6月9日:Functional and Responsive Macromolecular Brush Materials

  应固体润滑国家重点实验室邀请,美国田纳西大学教授Bin Zhao来我所交流访问,学术报告如下: 

  报告题目:Functional and Responsive Macromolecular Brush Materials 

  

 
报 告 人:Bin Zhao, Professor, Department of Chemistry, University of Tennessee Knoxville 

  报告时间:69日(星期五) 下午1500 

  报告地点:理化楼三楼多功能厅 

  报告摘要: 

  Linear  polymer chains densely  tethered by one end to a solid substrate  or a  polymer backbone are intriguing polymer systems, with the former being commonly called polymer brushes and the latter  being  descriptively  termed  molecular  bottlebrushes.  In  all  these  systems,  the  grafted polymer chains are highly stretched, exhibiting unique structures and  properties. In this talk, I will  present  two  types  of  macromolecular  brush  materials:  oil-soluble  polymer  brush-grafted nanoparticles (hairy  NPs) as  engine lubricant  additives  and  stimuli-responsive  shape-changing binary  molecular bottlebrushes.  While NPs  have been viewed as  potentially  effective  additives for  lubricants  for  friction  and  wear  reduction,  further  development  is  hindered  by  their dispersability and long-term stability in oils. By growing oil-soluble polymer brushes from NPs viasurface-initiated  polymerization,  we  have  shown  that  such  hairy  NPs  exhibit  excellent dispersability  and superior stability  in polyalphaolefin (PAO), the base oil  for  engine  lubricants. With addition  of 1 wt%  hairy NPs into PAO, significant reductions in friction  coefficient (up to  ~ 40%) and wear volume (up to ~ 90%) are achieved.  In the  second part of the talk, I  will present our recent work on stimuli-responsive  molecular bottlebrushes. A “grafting to” method  via  “click” reaction has been developed to synthesize molecular brushes; the modular nature and the high grafting  efficiency of this method allow  for  synthesis of  heterografted  molecular brushes  with two or more  distinct side chain polymers and facile tuning of the molar ratio of different side chain polymers. We show that thermosensitive binary heterografted molecular brushes undergo shape  changing  between  worm-like  and  collapsed  yet  stable  globular  conformations  upon temperature changes,  which  is  utilized to control  interactions between brushes  and environment. 

  报告人简介: 

  Bin Zhao 

  2013~ , Full professor, Department of Chemistry, University of Tennessee Knoxville. 

  2008-2012, Associate professor, Department of Chemistry, University of Tennessee Knoxville; 

  2002~2007, Assistant professor, Department of Chemistry, University of Tennessee Knoxville; 

  2000-2002, Postdoctoral research on microfluidics, University of Illinois at Urbana-Champaign; 

  2000, Ph.D. degree in polymer science, University of Akron; 

  1995, M.S. in polymer chemistry, University of Science and Technology of China; 

  1992, B.S. in polymer chemistry, University of Science and Technology of China; 

  His research interests include multicomponent polymer brushes, hairy particles, stimuli-responsive block copolymers and shape-changing molecular bottlebrushes, interfacial lubrication and adhesion. 

  He received Chancellor’s Award for Professional Promise in Research and Creative Achievement in 2010 and Paul and Wilma Ziegler Professorship from the University of Tennessee Knoxville, and Polymer Science Distinguished Alumni Award from the University of Akron in 2013. He was a member of Editorial Advisory Board of ACS journal Macromolecules (01/2009 – 12/2011). 

 

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