Structure-dependent re-dispersibility of graphene oxide powders prepared by fast spray drying  

作　　者：Yexun Shi Chang Li Liming Shen Ningzhong Bao 

机构地区：[1]College of Chemical Engineering,State Key Laboratory of Material-Oriented Chemical Engineering,Nanjing Tech University,Nanjing 210009,China

出　　处：《Chinese Journal of Chemical Engineering》2021年第4期485-492,共8页中国化学工程学报（英文版）

基　　金：the National Key R&D Program of China(2019YFD1101200,2019YFD1101204);Natural Science Foundation of China(51772150);the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Jiangsu Provincial Key Research and Development Program(BE2018008-1).

摘　　要：The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.

关 键 词：Graphene oxide powder Spray drying Re-dispersibility Oriented assembly Layered structure 

分 类 号：TQ127.11[化学工程—无机化工] TB383.3[一般工业技术—材料科学与工程]