Relation between the form of assembly of carbon fiber strands and the amount of attached microorganism was studied by using an artificial waterway set up at the side of the pond AZAMI. A variety of rectangular sail-type carbon samples were prepared by arranging a definite number of the strands (N) in parallel to each other in width of A cm and in length of B cm. These samples were placed on a setting frame with a length of L0, and then immersed in the circulating water pumped up continuously from the pond during the period of each four months in winter and summer. The amount of microorganism attached and proliferated in carbon fiber entanglement network was evaluated by weight increase(Winc). It was found that Winc depends on the relative length, B/L0 and the value of N/A, namely, compactness of the strand consisting of 12, 000 monofilaments. The former value was closely related to easy separation of the strand into monofilaments that gives rise to an increase in effective surface area of carbon fibers for initial attachment of microorganism, while the latter was a function of an effective volume of network in water for proliferation of microorganism. A suggestion obtained was, further, that aerobe microorganism was preferential species within the carbon fiber network perturbed by water flow which leads to an increase in the rate of exchange of water in the network and this probably be related to the high bending modulus of carbon fiber filament. A most preferable result for proliferation of microorganism was obtained at the condition of B/L0=1.4 and N/A=2.7, and the average distance between neighboring carbon monofilaments entrapped in the aggregates of microorganism reached to about 750μm corresponding to ca. 100-folds of the diameter of carbon monofilaments.
Making use of infra-red spectra and ’H NMR spectra, we characterized the molecular structure of polytrimethylene terephthalate (PTT) which was synthesized by ourselves, and compared the resulting PTT with polybutylene terephthalate (PBT) and polyethylene terephthalate (PET). The crystallization kinetics for PTT was compared with those for PBT and PET. The crystallization activation energies of these three polyesters were weakened in the order of PET>PTT>PBT. It seems that the difference in the flexibility of molecular chains influences the crystallization activation energies.
The folded chain structures in cellulose molecule were investigated through molecular dynamics simulation technique. The chain molecules based on the flexible ring structure model of glucose residues were applied for the simulation. The conformational transitions of the ring structures were not detected during the simulation near room temperature. The optimized structures of cellulose chains did not have 2-fold screw axis symmetries that were usually observed in the cellulose chains in the crystallites, so that fairly large stress energies were to be retained in the cellulose crystallites. The comparatively loose folded chain structures were also confirmed to be possible in the cellulose molecules in a cellulose II crystallites that were formed after chain molecules were created.
A cotton yarn was treated with a softening agent and a lubricating agent and the properties were estimated by hand and by a tensile tester. By hand test, the yarn treated with a softening agent was found to become softer with increasing amount of the agent, and the yarn treated with a lubricating agent was found to become smoother with increasing amount of the agent. By the tensile test, the slopes of the approximated lines at high elongation from the apparent differential modulus-strain curves(the approximated lines) for the yarn treated with the softening agent were found to become smaller with increasing amount of the agent, whereas the intercept of the approximated lines were found not to change. However, the intercepts of the approximated lines for the yarn treated with the lubricating agent were found to become smaller with increasing amount of the agent, whereas the slopes of the approximated lines were found not to change. The relation between the hand properties and the tensile properties were discussed.
Cellulose fibers removed from water plants, Elodea Nuttallii, were refined using commercial enzymes, pectinase “PL AMANO”, and the influence of the treatment on the α -cellulose content and the molecular weight for refined ones were investigated. At the optimal treatment condition, the α -cellulose content of ca. 80 % and the viscosity-average molecular weight of ca. 237, 000 were obtained. These low values were mainly due to the low maturity of cell walls of the water plants. A severe enzymic treatment lowered the molecular weight since the commercial enzymes slightly have β -gulucosidase activity.