Phase behavior of rotationally asymmetric Brownian kites containing 90°internal angles  

作　　者：Huaqing Liu Yiwu Zong Zhanglin Hou Thomas G.Mason Kun Zhao 柳华清;宗奕吾;侯章林;Thomas G.Mason;赵坤(Key Laboratory of Systems Bioengineering(Ministry of Education),School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China;Wenzhou Institute,University of Chinese Academy of Sciences,Wenzhou 325001,China;Department of Physics and Astronomy,University of California-Los Angeles,Los Angeles,CA 90095,USA;Department of Chemistry and Biochemistry,University of California-Los Angeles,Los Angeles,CA 90095,USA;Physics Department,Tianjin University,Tianjin 300072,China)

机构地区：[1]Key Laboratory of Systems Bioengineering(Ministry of Education),School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China [2]Wenzhou Institute,University of Chinese Academy of Sciences,Wenzhou 325001,China [3]Department of Physics and Astronomy,University of California-Los Angeles,Los Angeles,CA 90095,USA [4]Department of Chemistry and Biochemistry,University of California-Los Angeles,Los Angeles,CA 90095,USA [5]Physics Department,Tianjin University,Tianjin 300072,China

出　　处：《Chinese Physics B》2021年第12期467-472,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.11874277 and 21621004,and 11704276);the Natural Science Foundation of Tianjin,China(Grant No.19JCQNJC14900)。

摘　　要：Previous Monte Carlo simulations have shown that ordered tetratic phases can emerge in a dense two-dimensional Brownian system of rotationally asymmetric hard kites having 90°internal angles.However,there have been no experimental investigations yet to compare with these simulation results.Here,we have fabricated two types of micron-sized kites having internal angles of 72°-90°-108°-90°and 72°-99°-90°-99°,respectively,and we have experimentally studied their phase behavior in two-dimensional systems.Interestingly and in contrast to the Monte Carlo simulations,the experimental results show a phase sequence of isotropic fluid-hexagonal rotator crystal-square crystal as the area fractionφA increases for both types of kites.The observed square crystal displays not only a quasi-long-range translational order but also(quasi-)long-range 4-fold bond-and molecular-orientational order;these characteristics confirm that tetratic order can emerge even in dense Brownian systems of rotationally asymmetric particles.A model based on local polymorphic configurations(LPCs)is proposed to understand the origin of the square lattice order in these dense kite systems.The results in this study provide a new route to realize custom-designed self-assembly of colloids by controlling LPCs.

关 键 词：tetratic order colloidal kites two-dimentional system phase behavior 

分 类 号：O552.1[理学—热学与物质分子运动论]