Structure-Color of Iridescent Nanocrystalline Cellulosic CLC Films Varied with Input Sonication Energy
Chirality and repulsion interaction among sulfate cellulose nanocrystals (CNCs) have vital impacts on the formation of cholesteric liquid crystal (CLC) phase in the suspension or solidified film.In this work, a facile sonication treatment was applied to change the structure and repulsion interaction of CNCs and consequently tune the chiroptical properties of the resultant films.Results show that increasing sonication energy by improving input power or prolonging aging time caused the reduction of particle size, surface charge density, thereby increasing the cholesteric pitch and red-shifting the reflective wavelength of the iridescent films.The optical properties of the film followed the regulation of Bragg reflection and thin-film interference.However, over-energy input would cause multi-dispersion of CNCs according to the level of the surface charge density, thus leading to formation of polydomain CLC instead of planar CLC due to multi-distributed intra-axial drive forces.Hence, a schematic model was built up to describe the structure transition as well as the color variation and to make a connection between the mesoscopic behavior of CNCs and the microscopic interactions of electrostatic repulsion, hydrogen bonding affinity and chirality.Hence, we provided some meaningful information on building up hierarchical organization assembled from charged rigid biological rods, and help to recognize the structure-color mechanism of solidified polysaccharide nanocrystal films.
刘大刚 王硕 马忠实
南京信息工程大学化学系,南京,210044
国内会议
杭州
英文
249-249
2014-09-24（万方平台首次上网日期，不代表论文的发表时间）