Zhiqiang Luo, Hongzan Song, Xiaorui Feng, Mingtao Run, Huanhuan Cui, Licun Wu, Jungang Gao, and Zhigang Wang
志剛等在此感謝Langmuir期刊編輯和審稿人對于我們研究工作的理解和支持！ 感謝啊！
摘要: 利用偏光顯微鏡（POM）, 宏觀觀察，流變儀，小角X-射線散射，掃描電鏡以及透射電鏡觀察了埃洛石納米管水分散體系的液晶相行為和溶液-凝膠相轉變。 通過POM和宏觀觀察發(fā)現(xiàn)在1%HNT濃度時液晶相開始形成，到25%HNT濃度時全部液晶相形成。流變學測試說明當HNT濃度高于20%時，該分散體系呈現(xiàn)典型的剪切流動行為，并進一步證明溶液-凝膠相轉變發(fā)生在HNT濃度為37%時。而且，當鹽酸（HCl）加入到HNT水分散體系中，會發(fā)生pH誘導的凝膠化現(xiàn)象并伴隨著更強的雙折射。上述發(fā)現(xiàn)可望闡明各種拓撲結構的HNT體系的相行為，從而為制備長程有序納米物質奠定基礎。
Abstract: The liquid crystalline phase behavior and sol–gel transition in halloysite nanotubes (HNTs) aqueous dispersions have been investigated by applying polarized optical microscopy (POM), macroscopic observation, rheometer, small-angle X-ray scattering, scanning electron microscopy, and transmission electron microscopy. The liquid crystalline phase starts to form at the HNT concentration of 1 wt %, and a full liquid crystalline phase forms at the HNT concentration of 25 wt % as observed by POM and macroscopic observation. Rheological measurements indicate a typical shear flow behavior for the HNT aqueous dispersions with concentrations above 20 wt % and further confirm that the sol–gel transition occurs at the HNT concentration of 37 wt %. Furthermore, the HNT aqueous dispersions exhibit pH-induced gelation with more intense birefringence when hydrochloric acid (HCl) is added. The above findings shed light on the phase behaviors of diversely topological HNTs and lay the foundation for fabrication of the long-range ordered nano-objects.