摘要
在香蕉形液晶分子B4相态中,非手性香蕉形液晶分子自组装形成层状结构,分子在层内倾斜,形成层手性和自发极化,并且造成层内不匹配,最终形成纳米螺旋丝.本文设计了NOBOW/十六烷混合体系,在高温时,香蕉形液晶分子溶解于十六烷,在低温时,香蕉形液晶分子自组装形成纳米螺旋丝,并最终形成三维网络,变成有机凝胶.为深入理解纳米螺旋丝有机凝胶的特性,拓展其在软物质领域的应用,本文通过流变实验对该有机凝胶的黏弹性质进行了系统研究.实验表明纳米螺旋丝有机凝胶与传统凝胶不同,纳米螺旋丝有机凝胶可以随温度变化形成凝胶-流体的可逆变化,并且通过测量NOBOW/十六烷混合体系在不同液晶分子浓度、温度、应变大小和应变速率下的流变特征,揭示了该有机凝胶的流变特性与纳米螺旋丝的性质密切相关.
In the B4 phase of bent-core liquid crystals, smectic layers of tilted achiral bent-core molecules are chiral and polar, which, driven by intra-layer structural mismatch, eventually twist into helical nanofilaments. We design a NOBOW/hexadecane organogel system, which is different from traditional organogel system, and the studied organogels show reversible gel-liquid transitions under temperature cycles. At high temperature, the NOBOW molecules dissolve in hexadecane and the storage modulus and viscous modulus show typical liquid characteristics. At low temperature, the mobility of NOBOW molecules decreases and the storage modulus of the organogels increases as the temperature decreases. We conduct a rheology experiment to systematically investigate the viscoelasticity of the organogel to understand the property of the organogel and develop the application in soft matter. The viscoelastic studies of the organogels reveal that the helical nanofilaments are internally strained and their 3 D networks are relatively stiff, which provides an in-depth insight into the properties of the organogels and paves the way for their applications in soft matter.
作者
王行政
杨晨静
蔡历恒
陈东
Wang Xing-Zheng;Yang Chen-Jing;Cai Li-Heng;Chen Dong(Institute of Process Equipment,College of Energy Engineering,Zhejiang University,Hangzhou 310027,China;College of Materials Science and Engineering,University of Virginia,Charlottesville 22904,United States of America)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第8期197-203,共7页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11704331,21878258)
稀土资源利用国家重点实验室开放课题基金(批准号:RERU2019008)资助的课题.
关键词
香蕉形液晶
螺旋纳米丝
有机凝胶
黏弹性
bent-core liquid crystal
helical nanofilament
organogel
viscoelastic property