Water vapor sorption on collagen, which was extracted from chicken legs, was studied. A piezoelectric crystal is used as a microbalance in the sorption experiments. Two kinds of the collagen samples, namely film-type and fiber-type samples, were used for the sorption experiments. Film-type sample was prepared by casting an acetic acid (pH2.8) solution of the purified collagen onto a quartz crystal, and fiber-type sample was prepared by casting a phthalic acid-buffered (pH4.0) solution in which the purified collagen was dispersed. The sorption amount for the film-type sample was about twice as that for the fiber-type sample. The sorption behavior was analyzed by the cluster function, Flory-Huggins equation, and BET equation. The collagen sample was suitable for the application to humidity sensor.
The protein deterioration in mink hair under xenon arc irradiation was quantitatively evaluated by fourier transform infrared microspectroscopy (FTIR). Guard hairs of green skin of sapphire mink, tanned sapphire mink, green skin of dark mink and tanned dark mink were irradiated with a xenon lamp for 96 hours and subjected to FTIR analysis. Differential spectra taken in the wave number range of 1350_??_900cm-1 demonstrated that the absorption intensity at 1040cm-1 due to the -SO3- of the cysteic acid residues produced in irradiated hair was proportional to the irradiation time in the range of 12_??_96 hours. The relation between the both was expressed by a linear regression equation of y=ax (y: peak height or peak area of IR absorption, x: irradiation time, a: slope), the slope of the regression equation for dark mink was smaller than for sapphire mink, and so was for tanned skin than for green skin. The present method enables to evaluate the difference in the degree of deterioration among different and differrently processed mink hair samples.
A new preparation technique of cross-section for examining the fine structure of fiber and paper was investigated. A critical point in the structural characterization study of paper is to prepare cross-sections in a way the structure remains unchanged. However, the destruction of internal structure or creation of artifact in the thin sections during their preparation process even in a epoxy resin embedded sample is not avoidable. A focused ion beam (FIB) technique was applied as an improved method for a variety of papers. This technique has specially been used for fine processing of semiconductor or metals. Advantageous points of this method are as follows; (1) Sample temperature during the beam cutting is kept lower than 40°C, (2) Any optional area can be selected for sectioning, (3) A two step irradiation method is applicable for anisotropic composite materials. As a result, smooth cross-sections of a woodfree compressible paper and a double coated paper composed of materials with different hardness were successfully prepared and the micrographs with no structural change or artifact was satisfactory obtained. Further, a clear observation of printed ink transferred to paper was realized for the first time by this method.
The cellulase-hydrolysis of acetylcelluloses with acetyl substitution (DS) from 0.20 to 2.20 was assessed based on glucose and reducing end group production and changes in viscosity of substrate solution following enzymatic hydrolysis. The hydrolysis of water-soluble acetylcellulose by cellulase may be explained as due to DS, while that of water-insoluble acetylcellulose, not only DS but also the dissociation of substrate molecules brought about through solvation, swelling and dissolution of the substrate. Acetylcellulose with only DS=1.56 was found to undergo hydrolysis in aqueous cellulase solution subsequent to pre-swelling with 75 vol% aqueous ethanol. Acetylcellulose with higher DS (2.07) was hydrolyzed significantly in 80 vol% aqueous acetone by encapsulate cellulase. Acetylcelluloses with relatively high DS may thus be concluded to interact well with cellulase molecules and be hydrolyzed to varying degrees through the dissociation of solid substrates in appropriate organic solvents and cellulase can be used in such a way as to prevent it from coming into contact with the organic solvent.
PBZO's having average molecular length of 27, 49 and 128nm were crystallized from dilute solution in conc. H2SO4. At high crystallization temperature, the shorter PBZO (L_??_30nm) formed lath shaped lamellar crystals. Electron diffraction indicated that the long axis of the lamella to be along the crystallographic b-axis forming 100 twins, and that the molecular chains was perpendicular to the lamella. High resolution electron micrograph showed that 100 lattice fringe had an orientation distribution and curved within one crystallite. Decrease in crystallization temperature and/or increase in the chain length changed the morphology essentially into flat fibrils. Branchings through repetitive twinning across _??_100_??_ and _??_ planes lead to a square network. Vacancies in the fibrillar network were finally filled by post lamellar growth resuting in a mosaic structure, except with PBZO of the longest molecular chain. Oriented rigid cilia on the lamellar surface facilitated the growth rate of daughter crystals and regulated their orientation.
Sublimation/diffusion behaviour of a microencapsuled model disperse dye, 1-aminoanthraquinone (AAQ) into poly (ethylene terephthalate) (PET) film was evaluated applying the film roll method. Two kinds of microcapsules (smaller than 15μm in diameter) containing AAQ were prepared by using acrylate resin as capsul material. Fickian diffusion profiles of AAQ were obtained both from free state and from microcapsules in the measure temperature range from 170 to 200°C. Hence, the diffusion coefficients D could be calculated using the following equation: where Cis the concentration at distance x from surface after time t and A is a constant. From the temperature dependence of the D, the activation energy(ΔE) for diffusion was calculated. ΔE for diffusion from microcapsules was a little larger than that from free state. This fact indicates that the capsule wall affected as “a very low diffusion barrier”.
The contraction and recovery behavior of collagen film were observed in salt water and also water. The main results are as follows. 1. The collagen film showed contraction behavior in various salt water and showed recovery behavior in water. 2. The contraction behavior were shown remarkably under calcium ion and magnesium ion which were divalent ions especially. They were probably due to the volume changes of collagen film like ionic polymer gels. And these behavior were suggested that osmotic pressures of collagen film were different in monovalent and divalent ions. 3. The contraction rate was more than 40% of the value in almost saturated calcium chloride solution. 4. The relationship between contraction ratio and ionic strength of salt solutions was linear. It will be an important clue to explain the relationship between the contraction-relaxation of the gel and ionic strong. And this behavior was expected development ionic strong sensor. 5. The 90% response time of contraction or recovery was less than 1 minute. If the collagen film was used as sensing material to calcium ion, the response time satisfied the standard requirement for practical ion sensors. 6. The collagen film showed the contraction and the relaxation behavior under the loading which was loaded approximately in human almost muscle, and showed big work relatively.