Polymeric Flaky Nanostructures from Cellulose Stearoyl Esters for Functional Surfaces

Abstract

Herein, the preparation of polymeric flaky nanostructures (PFNS) from cellulose stearoyl esters as a novel platform for functional materials is reported. A temperature-induced crystallization process using solutions of cellulose stearoyl esters with a degree of substitution of 3 (CSE3) by decreasing the temperature from 55 °C to room temperature at a cooling rate of ≈1 °C min–1 is used. The molecular weights of CSE3, concentrations of polymer solutions, and cooling rates predominantly affect the formation of PFNS via this process. The PFNS are obtained as flakes within microsized flower-like particles or as organized patterns on diverse substrates (silicon wafers and glass fiber papers). The surface functional groups and surface roughness strongly affect the homogeneity and the amount of PFNS, allowing us to tune the structure of PFNS by varying these parameters. In particular, homogeneous flaky patterns of high amounts are formed on the surfaces containing aliphatic chains. By introducing sufficient amounts of flaky nanostructures on flat wafer surfaces or glass fibers within the glass fiber papers, superhydrophobic surfaces against diverse aqueous liquids and highly viscous glycerol are obtained. Thus, the formation of PFNS exhibits a robust and facile method for the fabrication of functional surfaces on diverse substrates.