An inorganic plasma exposure with short duration of the various glass substrate such as hard (Pyrex), neutral and soft glasses, generated stable paramagnetic centers, and were all detected by ESR spectra. The identical ESR spectra were also observed by UV irradiation using low pressure mercury lamp. Thus, UV radiation around 2537Å from the plasma is responsible for these param a gnetic centers. The electronic structure of the center was presumed to be a“hole trap”of the glass substrate. It was found that these centers lacked radical reactivities but had catalytic activities to generate the radical species of surface molecules.
On the other hand, an organic plasma exposure of the same glasses under th e similar conditions as above produced an ultrathin polymer film on the glass surface in the glow region, in addition to the UV-induced paramagnetic centers. Several kinds of these films can effectively trap the plasma-generated leftover radicals, resulting in the formation of long-lived organic free radicals. The PBN spin trapping techniques demonstrated that the long-lived free radicals thus formed were highly reactive to give intense ESR spectra of the spin adducts. Thus, the glass surface treated by organic plasma exposure can be functionalized w ith high catalytic acitivities for radical reactions and used for an initiation of the radical polymerizations.

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A porous silica, used as a support of metal catalysts, was thermally treated in an autoclave to modify its surface properties. When the silica was treated with water, ethanol, and 1-butanol at 250 ∼280°C and 10 ∼25 MPa, its surface area was fairly decreased, small pores less than 5 nm in diameter disappeared, and larger pores appeared. The temperature-programed desorption (TPD) of benzene indicated that there were weakly and strongly adsorbing sites on the original silica and the rate of benzene adsorption on the former sites was lower than that on the latter. On the treated silicas, however, there were only weakly benzene-adsorbing sites. The TPD of hydrogen showed that the nickel-loaded catalysts had two TPD peaks at ca.50°C and ca.270°C and the treatments of the silica caused the peak intensity at 50°C to decrease and the peak at 270°C to increase, while the platinum-loaded catalysts had a TPD peak at ca.100°C. For the nickel catalysts, the total amount of hydrogen desorbing up to 350°C was enhanced by the treatments of the silica, while it was decreased for the platinum catalysts. The catalysts on the silicas treated with the alcohols showed higher activities in benzene hydrogenation than those on the untreated silica. In benzene-to-cyclohexane conversion vs. temperature curves there were maxima, which appeared at 150°C for the nickel catalysts but they appeared at different temperatures (80 ∼450°C) depending on the support used for the platinum catalysts. The catalytic behavior of these catalysts was discussed in terms of the metal particle size, the benzene-adsorbing ability of the support, and the hydrogen-adsorbing ability of the catalyst.

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Surface processing of semiconductor materials was carried out in order to activate them for photocatalysis. There are two objectives in the present surface activation. One is to make them absorb visible lights and the other is to make them capable to oxidize water under illumination. Therefore, experiments were carried out to examine the possibility to prepare a composite material which has both the stability of an oxide and the light absorption capability of a sulfide. Titanium plate, zirconium plate, were processed. The processing consists of five cycles of heating in CS₂ (800∼900°C) and in O₂ (500∼600°C). Then Pt or Ni was combined with the product and the photocatalytic activity of the catalyst thus prepared was measured. Analytical data of X-ray diffraction, reflectance spectra, IR spectra and ESR spectra were recorded after each of the heating procedures of SrTiO₃ and SrZrO₃. In the cases of Ti plate and Zr plate, Xray diffraction and reflectance spectra were recorded after each heating procedure. The visible light absorption has been increased by the formation of multiple layers of sulfide and oxide on the surface of Ti and Zr plates. TiO₂ (anatase), ZrO₂, and HfO₂ after the processing generated hydrogen from the 1: 1 mixture of H₂O-2-propanol by visible light. SrTiO₃, SrZrO3and related compounds after processing generated H₂ and H₂O₂ from water when illuminated by visible light. The reason for the photolysis of the aqueous systems by the catalysts used in this work, when illuminated by visible light, will be due to formation of a new electronic energy band created by the doping of SO₂^-. The electrons may be excited from this band to the conduction band.

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Pretreatment of carbon electrodes through anodic oxidation resulted in enhancement of the oxidation peak of chlorpromazine (CPZ) on its cyclic voltammogram. The glassy carbon (GC)electrodes treated in phosphate, arsenate, tartrate, and citrate solutions exhibited especially marked enhancement. The peak current of CPZ was appreciably affected by the experimental conditions at pretreatment such as electrolyte, pH, and electrolysis potential and time. From ESCA and IR spectral observations and colorimetric analysis of the suspension of GC particles obtained from the electrode surface, modification of the electrode surface by formation of some species arising from such electrolyte anions was noticed. The newly formed species on the electrode surface are supposed to exert their activation effect on the oxidation of CPZ. These species are considered to function for accumulating CPZ by adsorption and for promoting the oxidation of CPZ with their catalytic action. The structural contribution of these anions to the effect was discussed.

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Formyl-substituted macroreticular polymeric resins were prepared by the Friedel-Crafts reaction of poly-(styrene-co-divinylbenzene) with dichloromethyl methyl ether followed by stirring in acid solution and removal of proteins from their aqueous solution by these resins packed in a glass column was examined. By the hydrophobic interaction and the Schiff base formation between proteins and polymeric resins, proteins were strongly bound to the resin. The adsorbed proteins cannot be eluted by acid, base or urea solution. The resin bound with alkaline phosphatase showed catalytic activity and good operational stability as a immobilized enzyme. Theoretical consideration were carried out to elution profiles of protein from the polymer-packed column.

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An electrochromic V₂O₅ film has been deposited onto a glass coated with an In₂O₃: Sn layer (ITO glass) and its electrochromic properties have been examined.
An aqueous solution of ammonium metavanadate (1/40 mol⋅dm-3) was passed through a cationexchange column to obtain monomeric decavanadic acid. Then it was concentrated by rotary evaporator and allowed to stand at 40°C for 100h. The monomeric decavanadic acid solution was gradually condensed to become a dark reddish, viscous colloidal solution of V₂O₅. This sol was then coated on the ITO glass and dried at 60°C. The V₂O₅ coated ITO glass was alternatively polarized anodically or cathodically in propylene carbonate-1 mole dm-3 lithium perchlorate mixture. On anodic polarization, orange color appeared, while on cathodic polarization, the color of green to gray appeared, reversibly.
Electron microscopic observation disclosed a th in oxide film with fibril structure of V₂O₅ microcristallites closely entangled with each other. These fibrils had a size of about 10 nm in diameter and about 1 pm in length, and contained an appreciable amount of water (about 15%by weight).

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Zn⁺, Cd⁺, Ti⁺, and Ar⁺ have been implanted into carbon for the surface modification. The doses of ions were 10¹⁶-10¹⁷ ions cm^-2 at an energy of 150 keV. In the case of diamond, distribution of the implanted element in the surface layer showed Gaussian-like distribution predicted by LSS range theory. An amorphous layer of twice thickness of the average projected range was formed by the ion beem bomberdment. Rutherford backscattering spectroscopy has been employed for these structural analysis. The amorphous surface layer shows high electrical conductivity, which is useful for inhibition of electrification of a diamond tool and a needle for disk-record. The concentration-depth profiles of the implanted element in glassy carbon substrates are also able to be predicted from the range theory, which was found from the results of a secondary ion mass spectroscopy. The zinc and titanium in the surface layer were defined as ZnO and TiO₂, respectivery, by a X-ray photoelectron spectroscopy. The amorphization of GC surface with ion implantation was found by a laser Raman spectroscopy. The electrochemical reactivity of ion-implanted elements in GC electrode surface has been investigated by means of a voltammetry. No oxidation and reduction of the elements were observed on the voltammograms. The electrode characteristics of ion-implanted GC have been evaluated from voltammetric behavior of the electrodes. The ion-implanted GC electrodes showed low residual current, high hydrogen overpotentials (except for Ti-implanted GC), and similar reactivities of redox reaction of [Fe(CN)₆]^3+/4+. These characteristics are useful for electroanalytical purpose of the electrodes.

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Amorphous Ni-B films were prepared by an RF glow discharge sputtering system that was discharged between the inside and outside electrodes of a reactor cell. It was used a high purity of Ar and B21-16d iluted with FI, as a sputtering atmosphere. The surface composition and the surface state of the films were examined by X-ray photoelectron spectroscopy (XPS). The amorphous state of the films was confirmed by X-ray diffraction measurement. It was found that the Ni-B films with various compositions were easily obtained and that the Ni-B films containing boron above 15 atom% became an amorphous state.
n Ni 2p 3/2 spectra of XPS a satellite peak appeared on the higher binding energy side of the main peak. With increasing the concentration of boron, the intensity of the satellite peakdecreased and the separation between the main and satellite peaks increased and the main peak became less asymmetric. This indicates that unoccupied d-holes of Ni are partly filled by the electrons transferred from B to Ni increasing electron density of nickel.
The hydrogenation of 1, 3-butadiene was carried out in a conventional clo sed circulation system over the amorphous Ni-B films. The product distributions was changed with the B concentration of the Ni-B films. This change could be associated with the electron density of nickel, that is, the hydrogenation ability of nickel increased with increasing the electron density of nickel.

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Well-defined graft copolymers having different kinds of backbones with hydrophilic, hydrophobic monomer units and a uniform molecular weight of polystyrene branches were prepared by a macromonomer technique to study their application as a surface modifier for polystyrene films. The polystyrene film specimens containing various amounts of these graft copolymers were fo rmed by means solvent casting on the micro glass slides and the surface properties of the specimens were studied by a contact angle measurement and X-ray photoelectron spectroscopy (XPS). The results are summarized as follows: ( 1 ) In the case of the graft copolymer having fluoroal kyl chains-backbone, the appreciable increase in the contact angle for water was obse rved with the increase in the graft copolymer concentration at the air side surface of the specime ns, whereas, on the glass side surface, the values of the contact angle were almost co nstant and the same as the pure polystyrene specimens. On the other hand, in the case of the gr aft copolymers having a backbone of hydrophilic monomer units, the remarkable increases in the wettability were observed at the glass side surface with the increase in the graft copolym er concentration, whereas, at the air side, the values of contact angle were almost the sa me as the pure polystyrene being independent of graft copolymer concentration except for a higher c oncentration region (above few %). ( 2 ) The amounts of hydrophilic backbone segments at the glass side surface detected by XPS were remarkably high compared with those in the bul k region, whereas none of the hydrophilic backbone segments could be detected at the air side surface, and the results of XPS were agreed with those of the contact angle measuremen t. ( 3 ) Both the values of the contact angle and XPS adruptly changed at about O.1 wt % and the change saturated at about O.5 wt % graft copolymer concentration at the glass side surfac e. Above this concentration these values were almost constant and the same as each of t he pure graft copolymers. ( 4 ) The amounts of hydrophilic backbone segments at the glass side surface also varied with the polystyrene branch length, and an optimum graft copolym er structure for surface accumulation is supposed to exist. These results were discussed in terms of the interfacial activity of graft copolymers in polystyrene matrix during the film format ion.

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Generally, good water wettability attained on hydrophobic polymer surfaces by exposing to a plasma discharge becomes poorer by aging in air and the contact angle gradually rises again. The following three explanations have been proposed as the reason contamination of the polymer surface, change in roughness of the surface, and overturn and migration of polar groups on the surface. In order to elucidate or examine which phenomenon is the most probable, we studied the wettability change of glow-discharged, hydrophobic polymer surfaces using a contact angle measurement with the sessile drop method. The most probable reason seems to be the overturn (e. g., for polyethylene) and the migration (e. g., for silicone) of the generated polar groups into the inside of the film, because the lowered wettability recovered again when the aged films were immersed in water for a prolonged duration.
n addition, the water wettability of poly(vinyl alcohol) (PVA) and cellulose hydrogels was studied by measuring advancing and receding contact angles by the inverted bubble method. A marked hysteresis of the contact angles was observed for PVA. This hysteresis is probably due to the overturn of the hydroxyl groups. On the contrary, no significant hysteresis was found for cellulose and both of the contact angles were as low as 13°. This fact was explained in terms of the chemical structure of the repeating unit of cellulose.

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Oxidation of titanium by additional O⁺-implantation and electrochemical properties of the Ti⁺-O⁺ implanted iron were studied for coloring and corrosion inhibition of an iron surface. The double-ion implantation with Ti⁺ and O⁺ in iron substrates was carried out with doses of 3×10¹⁶×10¹⁶, and 1×10¹⁷ Ti⁺/cm2 at 150 keV, and with 1×10¹⁶-2×10¹⁷O⁺/cm2 at 35 and 50 keV by means of a RIKEN 200 kV Low Current Implanter. Concentration-depth profiles of Ti were measured by secondary ion mass spectroscopy (SIMS). The profiles of Ti showed gaussian-like distribution which are predicted by the corrected LSS theory with sputtering effect. The oxidation state of the Ti in the surface layer were measured by X-ray photoelectron spectroscopy (XPS). The Ti is metallic in Ti⁺-implanted iron and TiO² is buried in the Ti⁺-O⁺ double-ion implanted iron. The anodic dissolution behaviour of the ionimplanted iron electrodes was studied by a cyclic voltammetry in acetate buffer solution of pH 5. The dissolution properties were related to the oxidation states of Ti and colors appeared with electrochemical oxidation. Depression of the anodic dissolution without coloring was seen for the Ti-implanted iron with the additional 1×10¹⁶ O⁺/cm2 implantation. Whereas, the color appeared after the anodic oxidation for the implanted iron with the oxygen closes higher than 1×10¹⁷ O⁺/cm2. implantation. Whereas, the color appeared after the anodic oxidation for the implanted iron with the oxygen closes higher than 1×10¹⁷ O⁺/cm2. The mechanism of the coloring has been explained by enrichment of Ti in the surface layer caused by the selective dissolution of iron from the Ti⁺-O⁺ im-planted iron surface. We concluded that the double-ion implantation will be applicable to the surface modification in order to achieve the coloring of iron surface as well as to inhibit the corrosion of iron.

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Chemical and physical properties of interlayered montmorillonite were determined by Xray diffraction and adsorption of N₂ and organic compounds. When Al₂O₃ and ZrO₂ were introduced into the interlayer of montmorillonite, the interlayered montmorillonite had the interlayer spacing of 8Å and showed a high surface area (>320 m²⋅g^-1) which was fifteen times that of montmorillonite. The surface areas calculated from adsorption of methyl -substituted benzenes were about one-half those determined by N₂ adsorption, indicating the presence of narrow pores.
Ru cat alysts supported on these interlayered montmorillonite were prepared from three Ru compounds and they were characterized by adsorption of H₂ and CO and by electron microscopy. When Ru₃(CO)₁₂ or Ru(NH₃)₆Cl₃ were utilized, fairly well dispersed Ru catalysts were obtained.
Hydrogenation of the methyl-substituted benzenes and CO were examined over the Ru cat alysts. It was found that 1, 2, 3, 5-tetramethylbenzene (molecular size; 8.0Å) was hydrogenated with very low efficiency as compared with non- to tti-methyl -substituted benzenes. This is considered to be due to the slow diffusion of tetramethylbenezene in the interlayer space. Thi s result presumably originates from the shape selectivity of the supports and shows th at most of Ru particles locates in the interlayer space.
In the CO hydrogenation, product distribution of hydrocarbons shifted to lower hydrocar bons such as methane as major product (>60%) as compared with Ru supported on Al₂O₃. Possible reasons of this result were discussed.

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There have been reported various types of silanol groups or hydroxyl groups contained in different types of colloidal silicas: they are absorbed water, silanol groups, geminal hydroxyl groups, inner hydroxyl groups, inactive hydrogen-bonded silanol groups on the surface, hydrogenbonded silanol groups between particle contacts and others. These hydroxyl groups, except for geminal hydroxyl groups which seem to be debatable, are found to be closely related with the pretreatment conditions or with surfaces and pore structures by a series of studies in this laboratory. This paper shows a review of these works and some of our new results.

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Three types of silica catalysts with sulfo groups were prepared. Silica was heated under reflux with 1, 3-propanesultone in toluene (type A). Silica was heated under reflux with sodium O, O'-diethyl(3-sulfonatepropyl)phosphonate in ethanol and then ion-exchanged Na for H (type B). Silica was heated under reflux with trichloro(phenethyl)silane in dioxane, and then heated under reflux with chlorosulfouric acid in chloroform (type C). These compounds were used as catalysts for 2-propanol dehydration and methyl t-butyl ether (MTBE) from methanol and isobutene. The activity, life, thermal stability of these catalysts were investigated.
On both react ions, the order of the catalytic activity were as follows; type C>type A>type B (Table 4 and 6). The rate constants of 2-propanol dehydration per acid site with type C and Amberlyst 15 were larger than these of type A and type B (Table 5). The rate difference may depend on the nature of their acid sites.
Type B catalyst was the most stable in thermal treat ment among the prepared catalysts (Fig.2, Table 3 and 4).
All of the prepared catalysts were active for MTBE synthesis. No deactivation was observed at 82°C for 6 h, When type A and type B were used. MTBE was synthesized with 100% selectivity (Table 6).

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A poly(ethylene terephthalate) film was treated with an argon plasma by low-frequency glow discharge and then exposed to the vapor of acrylic acid. The wettability of the film was measured by a contact angle of water and the effects of the treating conditions were examined. The treatment decreased the contact angle from 75° to 60∼35° (Fig.1); the discharge power and the duration of exposure to acid vapor were most influential. From XPS spectra, the surface layer formed was estimated to be less than 15∼20 Å. The electric conductivity along the surface increased by about one order (Fig.3), but it was insufficient to reduce the triboelectricity of the film.

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Silicon nitride powders of α- and β-types were activated by vibration ball milling, and the mechanochemical activation has been investigated by means of X-ray diffractometry and calorimetry. The specific surface area of two types of ground Si₃N₄ powders increased monotonically with the increase of grinding time. The fine grinding promoted the fragmentation of crystallites and an increase of lattice strain particularly in β-type. The surface energy of ground Si₃N₄ powders increased remarkably.

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In order to obtain new polymer film coated electrodes other than polyaniline electrode, the possibility of forming functional polymer films onto platinum electrodes by anodic oxidation of aniline derivatives has been examined. The products of electropolymerization of fourteen aniline derivatives can be classified as follows (Table 1): 1) Deposition of the electroactive polymer film which shows redox wave of polymer itself (o-phenylenediamine etc), 2) De- position of the electroactive polymer film which does not show any redox wave of polymer itself (N, N-dimethylaniline), 3) Formation of soluble products not adhering on an electrode surface (m-aminobenzenesulfonic acid etc), 4) Deposition of the electroinactive polymer film (o-chloroaniline etc). The basic characteristics such as conductivity, absorption spectra and redox potential of the electroactive polymer films were measured. Among the products obtained, poly(N, N-dimethyl aniline) and poly(o-phenylenediamine) electrodes showed unique properties compared with those of polyaniline (Table 3).

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Effects of codeposition conditions and surface chemical and electrochemical behavior in the electrodeposition of hard gold(gold-nickel)-alumina composite have been examined in order to clarify the codeposition mechanism. The alumina particles were scarcely codeposited in the absence of nickel ions in solution, but were codeposited in the presence of nickel ions owing to the adsorption of nickel ions onto the particles. Addition of caesium ions increased the amount of adsorbed nickel ions onto alumina particles and increased the codeposited alumina content: the codeposition of alumina particles from the acid gold-nickel electrolyte depends on the positive surface charge caused by the adsorption of nickel ions onto the particles. The positively charged alumina particle would be held by the electrostatic force of attraction on the negatively charged cathode electrode, and would be bound on cathode electrode by nickel atom produced by thereduction of adsorbed nickel ions and the electrodeposition of metal ions in solution. The codeposition process of alumina particle can be divided into the following three steps:
(1) Adsorption pro cess of nickel ions onto alumina particles;
(2) Holding process of alumina particle onto the cathode elec trode;
(3) Bonding process by the reduction of nickel ions onto alumina and the electrodeposition of metal ions in solution.
In the electrodep osition of hard gold-alumina composite, the codeposited alumina content was strikingly affected by the process (1).

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Electrochemical spectral sensitization has been attracting interest in connection with light energy conversion as well as the photosynthetic reaction in vivo. Recently we have found that the quantum efficiency of the photocurrent (q) for spectral sensitization depends largely upon the donor density (N_d) of the semiconductor substrate in SnO₂-xanthene dye systems. This phenomenon may provide us a key to understand the dynamics of spectralsensitization and to construct effective electrode systems for it. In this paper we tried to analyze the N_d dependence of q and the supersensitizing action of hydroquinone (HQ) (Fig.7) quantitat ively. A model for the reaction schemen was introduced as shown in Fig.9. Rate equations were derived (Fig.3) assuming that the electron, injected into the semiconductor surface from the excited dye, was trapped in the vicinity of the oxidized dye molecule. The solution for q was revealed to explain the experimental results as shown in Fig.11. The rate of electron re-injection (k₁ in Fig.9) and that of tunneling (k₃ in Fig.9) increases as Nd increases. The Nd dependence of q may be interpreted by a drift mechanism (Eq. (17)) when N_d is relatively small, and by field emission (Eq. (18)) or resonance tunneling when N_d exc eeds 10²⁰cm-3 (Fig.12). The process II in Fig.9 is deactivation of the injected electron, and its rate was estimated to be 3×10⁷s^-1. The value of q is determined by the competition between I and II in Fig.9 when N_d is small (Eq. (15)); q depends weakly in [HQ]. The pronounced dependence of q on [HQ] for high N_d's is explained by the suppression of the process III which being relatively slow (Eq. (13), Figs.7, 10 and 11).

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Monomeric and polymeric 1-alkylpyridinium compounds as redox mediators in the indirect electrochemical reduction of dihalo compounds were studied comparatively in aprotic solvents. A 4-ethoxycarbonyl-1-methylpyridinium cation was found to give two reversible cyclic voltammetric waves which may demonstrate the formation of corresponding neutral radical in acetonitrile and the anion at aat more negative potential. It was confirm ed by both cyclic voltammetry and preparative electrolysis that meso-1, 2-dibromo-1, 2-diphenylethane [3] and 1, 1-dibromo-2, 2-diphenylcyclopropane [4] could be reduced indirectly with electrogenerated and respectively. A platinum electrode which was chemically modified with 4-oxycarbonyl-1-methylpyridinium groups did not give any clear redox waves. At the next stage, a polymeric mediator having a molecular structure equivalent to monomeric one was examined in a similar way. Poly(4-vinyloxy-1-methylpyridinium cation) seemed to undergo reductive decomposition in DMF, while a coated pla tinum electrode mediated the reduction of [3] at the first wave potential in acelonitrile. The current at the second wave was so small that the coated-electrode could not be used for the the preparative electrolysis of [4]. As a conclusion, it was indicated that indirect electrochemical reactions were greatly affected by the status of mediators used.

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The heterojunction of CuO/ZnO is prepared by the chemical vapor deposition of ZnO on a CuO pellet or by contacting both sintered pellets by mechanical pressure and the currentvoltage characteristics (I-V characteristics) of heterojunctions are investigated. Only the mechanically contacted junction showed humidity-sensitive I-V characteristics. As the humidity increases, the current flow across the junction in forward bias increases markedly, resulting in highly rectifying character (Fig.2). This rectifying I-V characteristics is also observed when measured in distilled water (Fig.4). Therefore, it is assumed that the increase of the current in forward bias under high humidity is due to ionic conduction through physisorbed water at the interface of the junction. When the I-V Characteristics of the mechanically contacted junction were measured in various liquids, different I-V characteristics were observed, depending on the kind of liquids. The result suggests possibile application of this junction as a liquid-leakage sensor. However, metallic cupper was deposited on the ZnO surface after the application of high d. c. bias, resulting in considerable change in the I-V chracteristics (Fig.8).

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In order to find out a guiding principle for the improvement of the response of zirconia oxygen gas sensors below 500°C, measurements were made on the steady-state (Figs.3 and 7)and transient-state EMF (Fig.4 and Table 1), electrode interface conductance, σ_Ee (Figs.1and 8), and electrode capacitance, C_E (Figs.6 and 9), of oxygen concentration cells using HF treated and non-treated stabilized zirconia with Pt electrodes. With non-treated zirconia, the EMF of the cell abnormally deviated from the Nernst relation when temperature was abruptly changed (Fig.4). The response was improved remarkably by the use of HF treated zirconia. The EMF of this cell obeyed the Nernst equation as low as 240°C. The results were discussed based on the theory proposed before, and the followings were concluded. ( 1 ) Improvement of the response and prevention of abnormal EMF can be mad e by increasing a, and reducing CE (Eqs.3 and 4). ( 2 ) The GE is determined by the length of zirconia/Pt/O₂(g) triple phase boundary. The alternation of neither the chemical composition of zirconia surface nor the thickness of the Pt paste electrode affects the value of σ_E. ( 3 ) The C_E is determined by the amount of adsorbed oxygen on the zirconia surface in contact w ith the closed pores left at the zirconia/Pt interface (Eq.5. ). It can be reduced either by making the interface closely contacted or by changing the chemical composition of zirconia surface with, for example, HF treatment. ( 4 ) The improvement by HF treatment is due to the decrease in C_E. ( 5 ) It is suggested that the chemical modification of zirconia surface with a material which is less adsorptive for oxygen would result in the improvement of the response.

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An electrode was fabricated by covering a glassy carbon (GC) surface with a hydrophobic liquid membrane. The liquid membrane consisted of either a mixed membrane of plasticizer and poly(vinyl chloride) (PVC) or a microfilter impregnated with nitrobenzene. As the plasticizer for the PVC liquid membrane, diphenyl ether (DPE), dioctyl adipate (DOA), dioctyl phthalate (DOP), and nitrobenzene (NB) were tested on the basis of the required properties for the plasticizer such as nonvolatility, insolubleness in water, low viscostiy, and electrochemical inertness. Taking into account all of these requirements, it was concluded that DOP was the most appropriate, though it has one disadvantage that its viscosity was the highest among the plasticizer used.
On the electrode coated with, the D OP-PVC membrane, the cyclic voltammogram of an aqueous ferrocenecarboxylic acid solution showed a reversible redox wave, while that of hexacyanoferrate (II) solution showed no wave in the potential region around its equilibrium potential. This selective electrochemical reactivity for organic depolarizers against inorganic ones was also confirmed for the Fe²⁺-thionine system. Among the photochemical products of the Fe²⁺-thionine system, only organic leucothionine responded electrochemically on the gold optically transparent electrode (Au OTE) coated with the PVC liquid membrane. The result suggests that the present hydrophobic electrode is applicable to photogalvanic cells.
The electrode coated with the nitrobenzene impregnated microfilter also exhibited the similar selectivity.

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The electrochemical oxidation of o-phenylenediamine and N-methylaniline on basal-plane pyrolytic graphite electrodes in an acidic solution led polymeric film-coating of the electrode surfaces. The resulting poly(o-phenylenediamine) (PPD) and poly(N-methylaniline) (PMA)films showed reversible redox responses in aqueous solutions containing supporting electrolyte only. The film thickness and the surface concentration of the redox active site in films were proportional to the amount of the charge passed to prepare the films by a controlledelectrolysis. The PMA and PPD-coated electrodes revealed the selectivity for the redox reaction of dissolved substrates: in the case of the PMA-coated electrode, the oxidation of [Fe(CN)₆]^4- and the reductions of [Fe(CN)₆]^3- and [Irl₆]^2- could be mediated by the PM A film, while the film did not mediate the oxidation of [Ru(CN)₆]^4- and the reduction of N, N'-dimethy1-4, 4'-bipyridinium (MV²⁺) and functioned as a permselective film, ; in the case of the PPD-coated electrode, the reductions of [Fe(CN)₆]^3- and [IrCl₆]^2- could be mediated by the PPD film, but the oxidations of [Fe(CN)₆]^4- and [Ru(CN)₆]^4- and the reduc tionof MV²⁺ were not mediated. It is thus demonstrated that the PPD and PMA films can fun ction as electron-transfer mediators for the oxidation and reduction of dissolved substrates only in a limited range of potential, where dissolved substrates can be thermodynamically oxidized or reduced by the oxidized or reduced form of PPD and PMA films and that the electrodes coated with these films possess the property of“redox diode”.

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The mechanism of photocurrent generation in organic dye photodiode was studied by measuring both transient photocurrents with a nanosecond laser, and luminescence lifetimes with a picosecond laser and a time-correlated photon counting system. The photodiode consists of an evaporated merocyanine dye film sandwiched between two different metals such as Al and Ag. The lifetime of a singlet exciton in the evaporated merocyanine film determined from the fluorescence lifetime is about 200 ps. A simple analytical model of transient photocurrent was proposed. The model treats the system as a RC circuit with a rate constant for a recombination of charge carrier in the dye film. The intensity of the transient photocurrent gradually increases for several hundred nanoseconds after the excitation. From the analysis of the rise curves, it is concluded that the rise time is determined by the diffusion process of an exciton in the bulk of the dye film. These results infer that the charge carrier is generated from an intermediate species with a lifetime of more than several hundred nanoseconds.
Moreover, it is considered that the charge separation occurs not only at the inter face of the dye film and the metal but also in the bulk of the dye film. The decay time of the transient photocurrent was found to be determined by the RC constant of the circuit. The values of internal capacitances and internal resistances of the photodidodes were obtained. The rate constant of the recombination of charge carriers was also estimated to be about 5×10^-3 s^-1 Moreover, some interesting phenomena peculiar to pulse light excitation were observed.

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The cu rra t-d o ubling behavior of oxalate was studied at an n-type zinc oxide polycrystalline semiconductor photoanode. The increase in photocurrent due to oxalate was 92∼96% in a weak acidic electrolyte solution (pH 4.4∼5.6). However, it was found that in the weak acidic solution during the current-doubling reaction the zinc oxide photoanode dissolved.
On the other hand in the alkaline solution (pH 12.6), the photoanodic dis solution reaction of zinc oxide was completely suppressed and no current-doubling was observed. From the experimental results a reaction mechanism is proposed.

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Exsolution method was applied to the ceramics in the system Ni0-ZnO to control the microstructure in which the grain-boundary regions were rich in ZnO(n-type semiconductor)and the grains were NiO rich phases (p-type semiconductor) as detected by an electron probe microanalysis. The change in V-I characteristics with the change in relative humidity was measured at 25°C. Ni_0.2Zn_0.8O sintered at 1300°C for 5 h and further annealed at 800°C for 336 h was found to be the most sensitive to humidity.

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Effects of light intensity on the photoinduced potential changes across poly(vinyl chloride)(PVC) membrane entrapping a photoresponsive crown ether 4, 4'-bis[3, 4-(1, 4, 7, 10, 13-pentaoxatridecane1, 13-diyl)benzyloxycarbonyl]azobenzene [1] have been discussed. The photochemical isomerization reaction of [1] in the membrane proceeded rapidly when the membrane was exposed to higher intensity ultraviolet (UV) light, while longer time was required for attaining the photostationary state under weaker intensity light (Fig.3). The intensity of UV light as well as the membrane thickness affected the cis-[1] content in the photostationarystate mixture of the irradiated [1] in the membranes (Table.1).
The magnitude of the potential change was appreciably influenced by t he light intensity. The irradiation with higher intensity light resulted in the large potential shift, but the potential shift was small when the light intensity was low (Tables.2 and 3, Figs.5, 6 and 7). This trend of light-intensity dependence was significantly observed for thicker membranes, presumably because of the enhanced difference in cis-[1] content between the opposite surfaces of the thick membranes. These observations support that the photoinduced potential changes stem from the surface potential changes originating from the perturbation in charge density of the membrane surfaces.

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Chemical reaction at the surface of polyacrylonitrile (PAN) films by alkali treatment has been investigated by FT-IR-ATR spectroscopic method. The chemical species produced at the film surface were analyzed from the difference spectrum between the spectra before and after the reaction. The difference spectrum showed that the surface of the PAN film is partially hydrolyzed to produce polyacrylamide (PAAm) and poly(sodium acrylate) (PSA). A method was proposed to determine the chemical species at the surface of the film quantitatively. The quantitative determination was made by the use of the ratio of absorbances of the characteristic bands of each component at the treated film to those of each of component homopolymers in the ATR spectra. In the method errors caused by incomplete contact between the internal reflection element and the sample were corrected. It was found that PAAm was a chief product at the early stage of the reaction while the content of PSA increased with the progress of the reaction. When H₂O₂ was added into the reaction solution, PA Am was found to be a chief product at the film surface irrespective of the reactio n time. The reaction was limited to a very thin surface layer for PAN homopolymer. The alkali treatment was also investigated for copolymers of acrylonitrile and hydrophilic monomers such as N-vinyl-2-pyrrolidone or sodium 2-methyl-2-propene-l-sulfonate). In this case, the reaction occurred to a very large depth as compared with the homopolymer film.

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An imaging system based upon the peel apart procedure has been investigated. The imaging structure consists of a photochemically active layer comprising a polymer and a photosensitive material, a thin metal layer deposited on a substrate and a cover film laminated on the photosensitive layer. After imagewise exposure, following heating and peeling of the cover film off the base forms metal patterns on both the base and cover films.
In this paper, a possible imaging mechanism was proposed to explain the previous experimental results. In the positive working system, the adhesive strength between the photosensitive layer and metal interface was assumed to be increased by the formation of hydrogen bonds that are caused by light irradiation and heating. This result is the case in which poly(vinyl chloride) and 2, 6-bis(4-azidobenzylidene)-4-methyl-l-cyclohexanone were used for the photosensitive layer. In the negative working system of 1, 4-naphthoquinone and vinyl chloride-vinyl acetate-maleic acid terpolymer, the experimental results indicate the reduction of adhesion at the same interface by some photolyzed products.
In order to confirm the above mechanism, the photodecomposed products were separated by a liquid chromatographic procedure and the separated species were coated with the polymer onto the metal layer. It was found that adhesion between the polymer and matel interface was increased with increasing the amount and the polarity of added photoproducts. The proposed mechanism was demonstrated only for the positive working layer.
To clarify the negative working mechanism, electron spin resonance spectra of the photosensitive layer was measured after light exposure. A radical signal (g=2.0054) observed was decayed almost in the same manner as the dark change of imaging characteristics after illumination. The results suggest that the photoinduced radical in the photosensitive layer corresponds directly to the component which breaks hydrogen bonds at the interface.

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The effect of various ionic compounds (metal ions, ionic surfactants, lipid-soluble ions, and an antibiotic) on the electrostatic potential through the membrane-solution interface, has been studied using phospholipid monolayers and vesicles. Multivalent metal ions, ionic surfactants with long hydrocarbon chains, and a lipid-soluble anion have influenced effectively on the membrane surface potential.
Furthermore, the effect o f, metal ions on the uptake of organic ions through the phospholipid membrane has been studied for a lipid-soluble anion (tetraphenylborate; TPB) and an antibiotic (amphotericin B). It is found that metal ions control the adsorption behavior of thes e organic ions, i. e., the cations promote the adsorption of TPB and depress the rate of amphotericin B uptake. These effects are attributable to the change in membrane surface potential caused by the binding of metal ions.

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The X-ray photoelectron diffraction (XPED) method has been applied to the characterization of metal-semiconductor interfaces. For AufGaAs(110), Ge/GaAs(110) and Au/Ge(110) systems, the crystal regularity at the interface has been determined by the XPED method. The XPED patterns reveal that epitaxial growth of the deposited metal atoms takes place on the semiconductor surfaces in certain temperature ranges, while the structural regularity of these atoms disappears at elevated temperatures. The XPED patterns similar to those for the clean substrates are observed after the diffusion of the deposited metal atoms into the bulk. It is also shown that the XPED method can determine the atomic sites in the substitution reactions which take place at the interfaces: in the case of Au/GaSb(110), it is revealed that the Au atoms are substituted for Ga atoms after annealed at 540°C; in the case of Au/Ge/Ga As(110), it is found that both Ga and As atoms are replaced by Ge atoms, resulting in a Ge layer which has Ga and As atoms in its lattice sites. These investigations have proved that XPED is one of the most powerful and promising techniques for the characterization of the surface layer of metal-semiconductor contacts and will provide knowledge which will be useful for the practical device technology.

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The monolayer properties of bilirubin, known as one of bile conponents, and its binary mixtures with Cholesterol and lecithin were studied on the basis of their surface pressure-area isotherms obtained by varying pH values of substrate solutions with various concentrations of NaC1 in the presence and absence of 0.1 molls CaCl₂. The limiting area for bilirubin monolayer on 25 w/v% NaCl increased up to 1.3 nm2/molec. in the absence of CaCl₂, but by adding O.1 mol/l CaCl₂ to the substrate, it was reduced to 0.67 nm2/molec. Thiss uggests that both of the carboxyl groups of bilirubin molecule are anchored to the substrates and then bilirubin molecules orient in the condensed state to the water surface due to formation of monocalcium salt. In the case of binary mixture of bilirubin and cholesterol, the mean limiting area-mole fraction of bilirubin curve deviated positively from an ideal one independently from the presence or absence of calcium ion. This may be due to the repulsion between cholesterol and pyrrole rings. In the case of binary mixture of bilirubin and lecithin, the mean limiting area-mole fraction curve deviated negatively in the absence of calcium ion, but, by adding CaCl₂, the areas increased and the curve deviated positively. This may be due to an electrical repulsion force among calcium ions and lecithin molecules.

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Nylon membrane having hydrophilic poly(oxyethylene) side chains and cationic N⁺ sites was synthesized by allowing hydrophilic epoxy compounds containing ethylene glycol moieties to react with dimethylaminated Nylon 6 membrane. Amounts of cations and water content were varied by changing reaction time or kind of epoxy compounds. The membrane was further heparinized to obtain antithrombogenic membrane. The amount of heparin released from the membrane increased with increase in the water content of the membrane. The amount of heparin released from the membrane prepared by using bifunctional epoxy compounds was much smaller than that by monofunctional compounds.

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A unique membrane was developed by the reactive sputtering of a SnO₂ on a microporous Nucleopore film in an Ar-CH₄ atmosphere. The prepared membrane showed good oxygen permeation while preventing the permeation of water vapor. The gas permeability ratio (JO₂/J_H2O) of the typical membrane with the thickness of 0.1∼0.4μm is about 20. The service life of the zinc-air cell is improved remarkably by the application of the thin SnO₂ film as the O₂ permeation membrane.

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Cellulose diacetate was perfluoroacylated by straight-chain perfluoroalkanoyl chlorides, n-C_nF_2n+1COCl (n=4, 6, or 8), and by oligo(hexafluoropropene oxides), C_3n-1F_6n-1O_n-1COF (n=2, 3, 4, or 5). Critical surface tention values for the films prepared by these perfluoroacylated cellulose diacetates thus obtained were determined as γe 20∼21dyn/cm. In general, sufaces carrying a oligo(perfluoro ether) fraction gave lower γe values than those carrying a straight-chain perfluoroalkyl group with the same number of fluorine atoms.

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Homopolymers and copolymers composed of L-amino acids without charge were synthesized, and an interaction between these polymer membranes and cell was studied by a cell culture method. The cell line derived from a human gingival carcinoma (Ca.9.22) was used, and the initial cell attachment and rate of cell growth on the polymer membranes were measured, and morphology of cells attached on the polymer membranes was observed with a scanning electron microscope. The initial cell attachment, the rate of cell growth, and the morphology of cells were found to be considerably different among the polymers used, and the difference was attributable to that in the chemical structure of side chain of the polymers because all the polymers prepared had a-helical structure. Oxidized poly(L-methionine), hydrophobic copolymers containing L-leucine, and 3-amino-l-propanol-treated poly(γ-benzyl L-glutamate)had low percentage of the initial cell attachment (Table 2), and on these polymer surfaces filopodium of the cells could not be found and cells aggregated to form masses ( Fig.5).3-Amino-l-propanol-treated copoly(L-leucine, γ-benzyl L-glutamate), copoly(γ-methyl, glutamate, γ-benzyl L-glutamate), and poly(L-methionine) had high percentage of the initial cell attachment (Table 2), and on these surfaces filopodium of the cells could be found and the cells spread out extensively (Fig.5). The contact angle for water on the polymers with higher percentage of the initial cell attachment was in the range of 60 to 70degree (Fig.3). The rate of cell growth decreased with an increase in the percentage of initial cell attachment (Fig.4).

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Ethylene-vinyl alcohol copolymer derivatives were prepared by the reaction of 20 alcohols and 24 primary amines with the isocyanato group introduced into the copolymer side chain. Ca.9.22 epithelial cells were incubated on these copolymer films, and percentage of initial cell attachment, relative rate of cell growth and growth ratio were measured. The effect of the substituent groups in copolymer side chain on cell attachment, cell growth and contact angle of water were compared among the polymers prepared. The cell growth rate decreased with an increase in the initial cell attachment (Fig.3). The percentage of initial cell attachment showed a maximum at contact angle of around 60∼70° (Fig.5). The increase in the number of carbon atoms in alkyl groups resulted in the increase of contact angle, decrease in the cell attachment, and increase in the rate of cell growth (Fig.2). The aromatic ring effect to promote cell attachment was observed, and introduction of carboxyl group into the aromatic ring was even more effective. Introduction of long alkyl chains or water-soluble long molecular chains like poly(oxyethylene) group reduced the cell attachment remarkably.

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The surface-treatment of aluminum nitride was investigated by means of X-ray photoelectron spectroscopy, X-ray diffraction method, scanning electron micrography, as well as from dispersive and pyrolytic properties. The following results were obtained: (1) The surface of aluminum nitride was composed of aluminum oxide through the oxidation of aluminum nitride by an atmospheric oxygen or water, indicating that its surface was covered by hydroxyl groups; (2) The pyrolysis curve of the surface-treated aluminum nitride showed the same trend as that of the surface-treated aluminum oxide; (3) It was concluded that the surface group was formed by alkoxyl group of the alcohol used since the vapor evolved through the pyrolysis of the surface-treated aluminum nitride was mainly composed of the olefin corresponding to the alcohol. In conclusion, the surface of aluminum nitride could effectively be treated by the same method as that for aluminum oxide.

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The relationship between the microstructure and the humidity sensitive characteristic was studied for MaAl₂O₄ and MgFe₂O₄ elements. The microstructure of these elements was controlled by selecting starting materials and sintering conditions. The humidity sensitivity of the element for low relative humidity was enhanced with an increase in surface area and pore volume, expecially below 300Å in diameter. MaAl₂O₄ element, prepared by metal alkoxides and sintered at 1000°C for 5 h, exhibited a high humidity sensitivity. However, the response time was longer because the adsorption or desorption rate of water was controlled by the diffusion rate of water vapor through the micropores. As for MgFe₂O₄ elements, having a small surface area and a small pore volume, the impedance changes to the relative humidity changes were smaller than that of MaAl₂O₄ elements. The humidity sensitive characteristics of MgFe₂O₄ elements were influenced by both the microstructure and the impedance of the element at 0%1Z1-1. A theoretical calculation of the humidity sensitive characteristics was adapted for these element to clarify the relationship between the microstructure and the humidity sensitivity. In this calculation, all pores of the element were assumed to be filled with condensed water according to the Kelvin equation. The impedance of the element at a certain relative humidity was calculated by using the impedance of the element at 0%ZH, the porosity, the total pore size distribution, the conductivity of condensed water, electrode area and the thickness of the element. From the results obtained from the theoretical calculations, the conductivity of condensed water was found to be larger than 8.20×10^-7 S⋅cm^-1, which was an estimated value for the water exposed to the air containing 300 ppm of CO₂ at 20°C. This was confirmed by the conductivity enhancement of water after a boiling treatment of the specimen. Although the surface area and pore volume became larger after the boiling treatment, the impedance changes of the elements to relative humidity became smaller. This fact indicated that most of the dissolved ions existed on the surface of the element were washed out by this treatment. The theoretical calculation was also adapted for the elements after boiling treatment and the calculated values agreed approximately with experimental ones. Therefore, it was concluded that the humidity sensitive characteristics could be estimated by the theoretical calculation based on the pore size distribution.

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The removal of urea from dialysate or hemofiltrate is one of major problems for developing implantable or wearable artificial kidney systems.“Dialdehydestarch”(DAS)-Urease conjugates (DAS-DADPM-U and DAS-U) have been prepared to provide an effective chemisorbent for urea under physiological conditions. Urease immobilized on the surface of DAS particle hydrolyzes urea into ammonia (NH₃-ENH₄⁺). This ammonia then reacts with active formyl groups of DAS (Fig.2). DAS-DADPM-U was prepared by the coupling of diazotized DAS derivative with urease (Fig.3). DAS-U was prepared by the condensation of DAS with urease to form Schiff's base structure (Fig.3). When DAS having 80% of diformyl unit content was treated with a mild acidic solution of urease (ca. pH 5), the most active conjugate was obtained (Fig.4). The pH optimum of DAS-DADPM-U was at 7 (Fig.8). Its pH stability decreased in high pH range, when compared with that of native urease (Fig.9). Binding studies have shown that the capacity of urea uptake and the rate of urea uptake by DAS-U can reach 19.8 mg/g and 94%, respectively (initial concentration of urea, 2.00×10³mg⋅dm^-3; in dialysate; at 37°C; after 24 h) (Table 3). This capacity is 1.4 times greater than that of original DAS and far greater than that reported so far.

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The adsorption behavior of bovine serum albumin (BSA) onto styrene-acrylamide (AAm)copolymer(P(StfAAm)) latex was investigated as a function of pH and ionic streng th by determining the amount of BSA adsorbed. Polystyrene latex was used as a reference sample. First, the surface characteristics of P(St/AAm) and polystyrene latices were s tudied. Conductometric titration, viscosity and ζ-poetntial measurements of latex dispersions showed that the hydrated polyacrylamide (PAAm) layer existed on the surface of P(St/AAm) latex, and the thickness of its layer increased with increasing the amount of AAm used in the copolymerization (Table 2).
The plateau values of the adsorption isotherms (except the case of P(St/AAm20) latex)indicated, that BSA molecules adsorbed onto P(St/AAm) latex, as well as polystyrene l atex, in a side-on mode near the isoelectric point (iep) of this protein (pH about 5). The amount adsorbed showed a maximum near the iep of BSA. The pH at maximum adsorption shifted to a more acidic region with increasing ionic strength. Further, the amount of BSA adsorbed (particularly at ionic strength 0.1) decreased with increasing the amount of AAm used in the copolymerization, i. e., in the order, polystyrene>P(St/AAm₅)>P(St/AAm₁₀)>P(St/AAm₂₀), throughout the entire range of me asured pH (Fig.7). This result may be attributed to the effect of hydrated PAAm layer existed on the surface of P(St/AAm)latex. The most different point in BSA adsorption between P(St/AAm) and polystyrene latices was that the amount adsorbed onto P(St/AAm) latex was hardly discernible in alkaline region of pH.

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DSC, water absorption test, and X-ray photoelectron spectroscopy (XPS) were carried out in order to characterize the surface composition and microphase separated structure of segmented polyurethaneureas (SPUU's) composed of diphenylmethane-4, 4'-diyl diisocyanate ethylenediamine, and polyethers with different surface free energies and also various molecular weights, Mn. Polyethers used were poly(ethylene glycol) (PEG), poly (propylene glycol)(PPG), and poly(tetramethylene glycol) (PTMG).
DSC measurements revealed that the p hase mixing between the hard and soft segments proceeded with a decrease in Mn of polyether. The water absorption tests clarified the relative magnitude of surface free energy of each segment. The surface free energy increased in the order of PTMG≈PPG<hard segment<PEG. XPS revealed that an anisotropic distribution of the hard and soft segments existed on the air and substrate facing surfaces due to the difference in surface free energy of each component. This anisotropic composition became more distinct with an increase in degree of microphase separation. The concentration of the component with lower surface free energy increased with a decrease in sampling depth of XPS from the air facing surface. This result indicates that the interfacial free energy between polymer surface and air is minimized by concentrating the component with lower surface free energy on the air facing surface. Blood compatibility of SPUU's was evaluate d from the degree of interaction between blood platelets and the surface of SPUU.
Blood compatibility of SPUU was better than those of homopolymers composed of hard and soft segments. This means that the microphase separated structure may affect blood compatibility of SPUU. The Rn and surface concentration of polyether of SPUU, at which the minimum number of adhered and deformed platelets were observed, increased with a decrease in the magnitude of the surface free energy of the polyether components. It is concluded from the surface characterization and the test of blood compatibility that the blood compatibility of SPUU was affected mainly by the state of microphase separation, the surface composition, and the surface free energy of each segment.

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Effects of electric potential applied to a solid surface on cell adsorption were studied using sheep erythrocyte and semiconductive material such as In₂O₃ (or SnO₂)-evaporated transparent glass plate. The behaviors of erythrocyte on the semiconductive surface under potential application were directly observed with microscopic methods.
At the potential range from -0.2 to+0.5 V vs. AgAgCl erythrocyte cells came more frequently in contact with the surface depending on the applied potential. Some of the cells adsorbed on the surface. The number of the adsorbed cell became maximum on the, material surface whose potential was controlled at O.5V, whereas the number decreased gradually in the potential range from +0.5 to 1.5 V. When the electric potential of 1.3V or above was applied to the material surface, the adsorbed erythrocyte underwent degradation. Although the mechanisms of cell adsorption and cell degradation have not yet sufficiently been elucidated, the authors believe that electrochemical methods are very effective to the functionalization of material surface.

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Adsorptions of proteins (bovine pancreas trypsin, bovine serum albumin, and human rglobulin)as high-molecules onto various microspheres of homopolymer and styrene-2-hydroxyethyl methacrylate copolymer (P(S-HEMA)) were investigated in comparison with that of an emulsifier (sodium dodecylbenzenesulfonate) as a low-molecule onto them. All polymer microspheres were prepared by emulsifier-free emulsion polymerization technique. Plots of the maximum amount of the emulsifier adsorbed versus those of the proteins onto polyme r microspheres gave straight lines in the adsorption onto homopolymer, whereas no straight lines were obtained in the adsorption onto P(S-HEMA). These results may be attributable to the, surfaces of P(S-HEMA) microspheres having a phase separated structure which consists of both hydrophobic and hydrophilic parts.

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The dehydration and the dehydrogenation of 2-propanol took place over a graphite oxide catalyst to form propylene and acetone, respectively. The reactions proceeded by zeroth order kinetics. The formation of ether was not observed. Since the dehydration takes place over the acid sites and the dehydrogenation over the base sites, the presence of both acid. and base sites is suggested on the graphite oxide surface. The rate constants and the activation energies of dehydration and the dehydrogenation are: 3.61×10^-3 mol/⋅gmin and 100nwl for propylene and 2.07×10^-3mol/g⋅min and 104 k J/I-nol for acetone, respectively.

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Polyethylene glycol (PEG) is known to precipitate immune complexes in plasma and is use4, for the analytical determination of immune complexes. This interaction of PEG wa s used to separate immune complexes by incorporating PEG in network polymers. PEG with various molecular weights reacted with triisocyanate to form network polymers and the adsorption behavior of plasma proteins was investigated. It was found that the amount of adsorbed plasma proteins was dependent on the degree of swelling of the PEG-containing polymers and selective adsorption of immune complexes on the PEG-containing polymers was observed.

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Cobalt was deposited on poly(ethylene terephthalate) (PET) films by a RF ion-plating technique. The adhesion at the cobalt thin layer-PET film interface was investigated, and the following results were obtained:
By applying a RF power above 50 W and an accelerating voltage above 750 V on the ion plating process, the cobalt thin films adhered strongly on PET films were prepared. It was confirmed by XPS and FTIR-ATR techniques that the good adhesion of the ion-plated cobalt thin films was attributed to formation of a cobalt oxygen-carbon complex and a cobalt oxide layer at the cobalt layer-PET film interface.

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Isocyanato groups were introduced onto the surface of an ethylene-vinyl alcohol copolymer film by urethanation with hexamethylene diisocyanate. The films having amino groups or gelatin molecules on the surface were prepared by modifying the isocyanato group of the copolymer film. The adhesion through the covalent bonding of the two surface-modified films was studied. When the film with the isocyanato group was lapped over the film with the amino group under a pressure in dry state, no adhesion took place. This may be explained in terms of roughness of the surfaces which prevents the two films from effective molecular contact. When a gelatin-glutaraldehyde mixture was used as an adhesive for bonding the two films, both of which had amino groups, the peel strength was apparentl y higher than that estimated from the experimental error. For instance, the dry peel strength was 30 g⋅cm^-1 when the two gelatin-bound films were bonded with the adhesive. When adhesion was carried out after capping the functional groups, the peel strength became practically zero. The result strongly indicates that adhesion through the covalent bonding occurs between the two films having the functional groups on the surface, if the adhesive, capable of reacting with the groups, is used.

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