Small-angle neutron scattering studies of chemical reaction and reaction-induced self-assembly

Tanaka, Hirokazu; Koizumi, Satoshi; Hashimoto, Takeji; Kurosaki, Kazuhiro*; Omae, Masashi*; Kobayashi, Shiro*

We have investigated a self-assembling process of cellulose artificially synthesized via enzymatic polymerization by means of in-situ and time-resolved small-angle neutron scattering (SANS). The results elucidated the following: (1) cellulose molecules were synthesized at a special reaction site of the enzyme (cellulase) located on or near the smooth surface of the self-assembled enzymes formed in the reaction medium; (2) the synthesized molecules associated themselves via diffusion-limited aggregation (DLA) and crystallized into fibrils and (3) the fibrils formed the aggregates, which had the surface fractal dimension D increasing from 2 to 2.3 with the reaction time, on the smooth surface of the enzyme aggregates.