Silica aerogels/acrylic resin composites were prepared to develop a heat insulating material. Silica aerogels are synthesized from TMOS and its oligomer. Silica aerogels from TMOS have uniform particle and pore sizes. Although those from the oligomer have a distributed particle and pore sizes, it was found that the silica aerogel with low thermal conductivity can be obtained from the oligomer by optimizing the reaction conditions. The mixture of the silica aerogel and an acrylic resin has a high viscosity and the composite film cannot be obtained. Additionally, the surface modification of silica aerogel was carried out. A composite film was prepared from a mixture of surface modified silica aerogel and acrylic resin. The addition of the surface modified silica aerogel reduces the thermal conductivity by about 44 per cent.

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The aim of this research is to evaluate the adhesive property of UV-curing ink on a non-porous surface. Generally speaking, it seems that surface tension and shrinkage of functional monomers are very important factors for a good adhesive property of the cured film. We found that the flexibility of the cured film is influenced by the chemical structure of both di- and tri-functional monomers. The flexibility seems to be crucial in improving bonding strength. It is important for the tri-functional monomer to have long-chain spacer groups in order to get a good adhesive property. Meanwhile, di-functional monomers having long-chain spacers, tend to form a dense network structure among the ink components. In this case, the cured films show a poor adhesive property.

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Preparation of N-chlorinated bacterial cellulose (BC) and its ultra-thin sheet-making were investigated. N-chlorinated BC was prepared by a three step reaction: cyanoethylation, carbamoylethylation and N-chlorination. Cyanoethylated BC of DS (degree of substitution) 0.05 was prepared Michael addition with acrylonitrile at 40°C for about 2.5 h. Carbamoylethylation of cyanoethylated BC readily proceeded by addition of H₂O₂ at room temperature (20°C) and reached DS 0.05 for about 1 h. In the third step, carbamoylethyleted BC easily reacted with NaClO and gave N-chlorinated BC. The dry tensile index of N-chlorinated BC sheet (10 µm thickness) was about 1.7 times higher than that of a BC sheet, and the wet tensile index was about 3.6 times higher. By N-chlorination of BC, we could prepare sheets down to a thickness of 3 µm. Increasing inter-fiber bond formation of N-chlorinated BC is the reason for improving the sheet-formation.

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In this paper, we have investigated the influence of the structure of carbon nanotubes (CNTs), polymers and solvents on the formation of honeycomb structure films of CNTs/polymers. Casting non-polar solvents that contain CNTs, a dispersant polymer and an amphiphilic polymer under high humidity produced honeycomb structure films on the substrate. Combination of narrow radius multi-walled CNTs and an acrylate copolymer-type dispersant bearing pyrene and long alkanes provided ordered honeycomb structured films. Using a dispersant that contains a hemiacetal as an acid-responsive function improved the properties of the formed composite honeycomb films by an acid treatment as a trigger.

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A simple statistical mechanical treatment of the behavior of resin materials during kneading is put forward in this paper. The concept of “entropy of structure diversity” (“diversity entropy”) is used to describe the origin of diverse structures of material particles that appear transitionally during the kneading process. The diversity entropy was calculated from the number of different complexions of the particle group caused during kneading of the materials. The diversity entropy was calculated for a linear series and a block of elemental particles during kneading, respectively. The equation of a kneading free energy of a multi-component system was derived, assuming that the kneading entropy is equal to the sum of mixing entropy and diversity entropy. The midpoint of the kneading transition range was shown to correspond to the kneading time of the maximum diversity entropy, calculated by using measured values of the curing heat for the kneaded compounds.

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Field-flow fractionation (FFF) is one of the promising alternative separation techniques to size exclusion chromatography (SEC). In this study, water soluble polymers including Bovine Serum Albumin (BSA), pullulan, poly(ethylene oxide) (PEO), sodium poly(styrene sulfonate) (NaPSS), and partially saponified poly(vinyl alcohol) (PVA) have successfully been characterized by a means of the FFF technique, fitted with a multiangle laser light scattering (MALS) detector in 0.1 M Na NO₃ as an eluent at 25°C. The factors which affect the retention time, t_r, and the separation factor, R_s, of the monomer and dimer of BSA are the thickness of spacer, w, channel flow rate, V_CHF, cross-flow rate, V_CRF, focusing time, injection volume, and polymer concentration, C_p. We found that the retention time, t_r, in the FFF follows the equation of t_r~[V_CHF]^−1.0[V_CRF]^1.0[w]^2.0, in agreement with theory. Several cross-flow rates were examined for the characterization of the water soluble flexible polymers and the polyelectrolyte, and an appropriate gradient method for these polymers is found to be described by the equation of V_CRF = A exp (−Bt_r), where A and B are constant. For the polyelectrolyte, the retention time significantly varies with salt concentration, due to the balance between change in the conformation of polyelectrolyte chains and the electrostatic exclusion from the membrane filter.

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Endotoxins are a major component of the outer membrane of Gram-negative bacteria. Since they lead to multiple pathophysiological effects, efficient removal of endotoxins from biological and pharmaceutical products is essential. We successfully prepared polymer hydrogel beads with endotoxin adsorption sites by applying a molecular imprinting technique, using a triazine derivative as a functional monomer, that was polymerized in an inverse-phase suspension. The gel beads showed a high adsorption capacity for endotoxin, and exhibited a preferential binding for endotoxin rather than BSA. These results suggest that the gel beads can be employed for an endotoxin adsorbent.

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