Peculiarities of cellulose nanoparticles

Abstract

The effects of sulfuric acid concentration and temperature have been studied to optimize the preparation of crystalline nanoparticles (CNP) and amorphous nanoparticles (ANP) of cellulose. To isolate CNP with increased yield (67%-70%) requires hydrolysis with warm 58-60 wt% sulfuric acid. CNP having average sizes of 150 × 15 nm and heightened yield can be obtained by using optimal hydrolysis conditions together with vigorous disintegration. Because of its highly crystalline structure, CNP have increased specific gravity and low hydrophility and accessibility. CNP potentially can be used as a nano-filler to improve properties of pastes, glues, paints, and coating compositions. To isolate ANP having an average diameter of 100 nm with the optimal yield (65-67%), cold 65-66 wt% sulfuric acid should be used in combination with vigorous disintegration. Because of their amorphous structure, ANP acquire such specific features as increased content of functional groups, high accessibility, enhanced sorption ability and hydrophility, and high viscosity and thickening ability. Given the specific features of ANP, their main application area might be for immobilization of biological active substances and drugs, filling and thickening of cosmetic and medicine remedies (e.g., pastes, creams, sprays, etc.).