向列相溶致液晶旋转黏度研究  

STUDY ON ROTATIONAL VISCOSITY OF NEMATIC LYOTROPIC LIQUID CRYSTAL

作　　者：陈凌峰[1] 于佳佳[1] 李友荣[1] 黄映洲 李谷元 Chen Lingfeng;Yu Jiajia;Li Yourong;Huang Yingzhou;Li Guyuan(Key Laboratory of Low-grade Energy Utilization Technologies and Systems of Ministry of Education,School of Energy and Power Engineering,Chongqing University,Chongqing 400044,China;Chongqing Key Laboratory of Soft Condensed Matter Physics and Smart Materials,College of Physics,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学能源与动力工程学院低品位能源利用技术及系统教育部重点实验室,重庆400044 [2]重庆大学软凝聚态物理及智能材料研究重庆市重点实验室,重庆400044

出　　处：《力学学报》2021年第4期998-1007,共10页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金青年科学基金(51806025);重庆市留学人员创业创新支持计划(cx2019053);油气藏地质及开发工程国家重点实验室(西南石油大学)开放基金(PLN2020-8);中央高校基本科研业务费(2018CDXYDL0001)资助项目。

摘　　要：溶致液晶具有良好的生物相容性、无毒性、生物降解性以及光学、电磁学各向异性等,在细胞相互作用、神经刺激传递、脂肪吸收、药物智能输运等生命活动研究、医药工程和液晶显示等领域有广泛应用.本文采用旋转磁场法测得溶致液晶日落黄在不同温度和溶液浓度下向列相时旋转黏度,并结合溶致液晶分子自组装过程,理论分析了溶致液晶向列相旋转黏度随温度和溶液浓度的变化规律.研究结果表明:溶致液晶旋转黏度与液晶分子自组装柱状体平均长度的平方呈正比增大关系,随溶液浓度的增大而增大,随温度的升高表现出指数减小的规律.构建了与向列相溶致液晶温度和浓度相关的旋转黏度经验表达式,经验表达式计算结果与实验值吻合较好,最大误差仅为18.56%.提出采用旋转流变仪间接获得溶致液晶剪切能的新方法,溶致液晶剪切能随溶液浓度的增大而增大,但在实验温度范围内,溶致液晶剪切能几乎不随温度而改变.利用旋转流变仪间接获得的溶致液晶剪切能与报道的利用X-Ray检测所得的结果之间最大误差仅为3%.成功地利用了液晶分子自组装能力随温度的变化规律来研究柱状体长径比对旋转黏度的影响规律,创新地提出了“一步法”测量研究,大大减少相关实验研究的成本和复杂性.Lyotropic liquid crystal exhibits excellent biocompatibility,non-toxicity,biodegradability,optical anisotropy,and electromagnetic anisotropy.It has been widely used in the areas of biology,medical engineering and liquid crystal displaying,such as cell interaction,nerve stimulation transmission,fat absorption and intelligent drug transport.In this paper,the rotational viscosity of the lyotropic liquid crystal Sunset Yellow in the nematic phase at different temperature and solution concentration is measured by the rotating magnetic field method.Combined with the self-assembly process of lyotropic liquid crystal molecules,the variation of rotational viscosity of lyotropic liquid crystal in the nematic phase with temperature and solution concentration is analyzed theoretically.The results show that the rotational viscosity of the lyotropic liquid crystal is positively correlated with the square of the average length of the self-assembled columns,increasing with the increase of concentration,but decreasing exponentially with the increase of temperature.The empirical expression of rotational viscosity related to temperature and concentration of nematic lyotropic liquid crystal is constructed.The calculated results of the empirical expression are in good agreement with the experimental values,with the maximum error of 18.56%.A new indirect method of obtaining the shear energy of lyotropic liquid crystal by using rotating rheometer is proposed.The shear energy of lyotropic liquid crystal increases with the increase of solution concentration,but it is hardly related with the change of temperature in the experimental range.The shear energy obtained in this paper is in good agreement with the results of Joshi et al.who used the X-ray detection method,with the maximum error of 3%.The influence of length-diameter ratio of the columns on the rotational viscosity is investigated by using the variation of self-assembly capacity of liquid crystal molecules with temperature.The“one-step method”measurement is proposed,which gre

关 键 词：溶致液晶 向列相 旋转黏度 剪切能 经验表达式 

分 类 号：O357[理学—流体力学] O373[理学—力学]