Electric-Field Alignment of Chitin Nanorod鈥揝iloxane Oligomer Reactive Suspensions

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• 作者：Maria Yu. Boltoeva ; Ivan Dozov ; Patrick Davidson ; Krassa Antonova ; Laura Cardoso ; Bruno Alonso ; Emmanuel Belamie
• 刊名：Langmuir
• 出版年：2013
• 出版时间：July 2, 2013
• 年：2013
• 卷：29
• 期：26
• 页码：8208-8212
• 全文大小：301K
• 年卷期：v.29,no.26(July 2, 2013)
• ISSN：1520-5827

文摘

Uniaxially anisotropic chitin鈥搒ilica nanocomposite solids have been obtained thanks to the electric field-induced macroscopic alignment of liquid-crystalline reactive cosuspensions. We demonstrate how chitin nanorods (260 nm long, 23 nm thick) can be aligned upon the application of an alternating current (ac) electric field, and within water鈥揺thanol suspensions containing reactive siloxane oligomers (D_h 3 nm). The alignment at the millimeter length scale is monitored by in situ small-angle X-ray scattering (SAXS) and polarized light optical microscopy. The composition and state (isotropic, chiral nematic) of the cosuspensions are proven to be determining factors. For nematic phases, the alignment is preserved when the electric field is switched off. Further solvent evaporation induces sol鈥揼el transition, and uniaxially anisotropic chitin鈥搒ilica nanocomposites are formed after complete drying of the aligned nematic suspensions. Here, the collective response of colloidal mesophases to external electric fields and the subsequent formation of ordered nanocomposite solids would represent a new opportunity for materials design.