우수한 분산성을 갖는 CNF 분말 제조를 위한 화학적 표면 개질과 첨가제 투입

As cellulose nanofibrils (CNFs) are produced at a low concentration in water, they need to be dried to increase their shelf life and reduce transportation costs. However, when CNFs are dried, they are difficult to redisperse due to hornification. In this study, the chemical surface modification of CNFs and additive addition were investigated to fabricate a CNF powder that shows good redispersibility. The chemical modification was achieved by introducing additional carboxyl groups onto the surfaces of the CNFs. Electrolyte and polyelectrolyte were respectively added to the CNF suspension before they were dried. Then, the dispersibility, Turbiscan stability index, morphologies, and viscosities of the redispersed CNFs were measured. It was observed that upon an increase in the carboxyl group content, there was in improvement in the redispersiblity of the CNFs. When carboxymethylcellulose was used as an additive, the dispersion stability of the CNFs was much improved due to the electrostatic repulsion and steric hindrance that occur between the nanofibrils. However, mono- and di-valent electrolytes were found to not improve the dispersion of CNF powder. KCI Citation Count: 0