Controlling the Reflection Wavelength of Iridescent Solid Films of Nanocrystalline Cellulose
Controlling the Reflection Wavelength of Iridescent Solid Films of Nanocrystalline Cellulose
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DOI：
10.1021/bm1010905
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发表时间：
2011-01-01
影响因子：
6.2
通讯作者：
Berry, Richard
中科院分区：
文献类型：
--
作者：
Beck, Stephanie;Bouchard, Jean;Berry, Richard
纳米晶纤维素（NCC）在悬浮液中自组装，干燥后形成彩虹色的手性纳米纤维素薄膜，可以反射特定波长的圆偏振光。现在已经发现，超声处理增加了悬浮液中的手性双折射螺距，并且随着施加能量的增加，NCC膜的反射波长发生红移。超声处理和电解质添加相结合，使膜的反射性能可预测地调整。超声处理NCC混悬液的影响是累积性和永久性的。可以将用不同能量输入超声处理的悬浮液混合，以得到具有介于从各个悬浮液获得的反射带之间的反射带的NCC膜。这些数据表明，超声波引起的红移是静电的性质。
Nanocrystalline cellulose (NCC) self-assembles in suspension to form iridescent chiral nematic films upon drying that can reflect circularly polarized light at specific wavelengths. Ultrasound treatment has now been found to increase the chiral nematic pitch in suspension and red-shift the reflection wavelength of NCC films as the applied energy increases. Sonication and electrolyte addition combined allow the reflective properties of the film to be predictably tuned. The effects of sonicating an NCC suspension are cumulative and permanent. Suspensions sonicated with different energy inputs may be mixed to give an NCC film having a reflection band intermediate between those obtained from the individual suspensions. The data suggest that the ultrasound-induced red-shift is electrostatic in nature.