北京化工大学

 

Tel: 010-64455618 E-mail: liujun@mail.buct.edu.cn or lj200321039@163.com; Homepage: http://www.caem.buct.edu.cn/szll/jsjl/34903.htm

2013.7-现在          北京化工大学材料科学与工程学院副教授， C类人才海外引进

2011.7-2013.7      美国密西根大学化学工程专业， 博士后 ，导师：美国工程院院士Ronald Gary Larson

2003.9-2011.6    北京化工大学高分子材料科学与工程专业， 本硕博连读，导师：第一导师教育部长江学者、国家杰出青年基金获得者张立群教授; 第二导师教育部新世纪优秀人才支持计划曹达鹏教授

2015年09月 获第二届中国国际复合材料科技大会（CCCM-2）优秀论文奖

2013年09月 北京化工大学C类人才引进启动基金

2010年10月 获得中国石化 “英才奖学金”

2010年1月 获得第十六届全国复合材料学术会议优秀论文奖

2009年6月 获得北京化工大学 “十大学术之星”称号

2009年5月 获得北京化工大学 “优秀研究生(博士生)” 称号

2008年11月 获得日本住友橡胶奖学金

2008年4月 获得北京化工大学 “优秀研究生(硕士)”称号

三. 主要研究方向：

为实现高分子纳米复合材料具有优异的力学、物理与多功能性能，本人采用实验与计算机模拟手段相结合的方法，从分子水平上对纳米颗粒的特性、分散、界面物理化学结合、大分子链物理化学结构来设计制备新型纳米复合材料。围绕这些基础科学问题，目前以第一作者与通讯作者身份发表论文20余篇，包括Advanced Functional Materials, Macromolecules, Soft Matter, Langmuir, Nanotechnology等国际权威期刊，期间参加学术会议共10次，做口头报告6次。目前承担国家自然科学基金一项，国家973两项，北京市教委两项，企业项目一项，北京化工大学启动基金一项，累计共两百余万。

(a)通过计算机模拟技术首次考察了纳米颗粒在聚合物熔体中的扩散行为，并对Stokes-Einstein定律的正确性进行了检验(Journal of Physical Chemistry C, 2008, 112, 6653)。模拟结果发现在纳米颗粒尺寸大于分子链回转半径时( ), Stokes-Einstein方程能准确描述纳米颗粒的扩散行为， 而对 时，由于纳米颗粒只探测到nano-viscosity而导致 Stokes-Einstein出现较大的偏差。该模拟结果很好的解释了Mackay等人在实验上的观察结果(Nano Letters, 2007, 7, 1276)。 该文章目前已被引用70次，包括Progress in Polymer Science, Chemical Society Reviews, Soft matter, Macromolecules,  Physical Review E等国际著名期刊。

(b)模拟了聚合物纳米复合材料体系分子链动力学性能，首次发现了纳米颗粒对分子整链松弛(terminal relaxation)的影响存在时间-温度-浓度等效性(time-temperature-concentration)的关系(Macromolecules, 2009,  42, 2831)。实验上在研究炭黑(carbon black)填充的高密度聚乙烯(HDPE)时也证实了该结论(Journal of Rheology, 2009, 53, 1379)。该文章被包括Macromolecules与Soft matter等引用。

(c)系统模拟了纳米颗粒与表面接枝高分子链改性纳米颗粒在聚合物基体中的分散行为与机理(Langmuir, 2011, 27, 7926; 2011, 27, 15213)；聚合物分子链与纳米颗粒界面物理与化学相互作用(Physical Chemistry Chemical Physics, 2011, 13, 13058)以及首次采用计算机模拟对聚合物纳米复合材料的力学性能( )进行了考察(Physical Chemistry Chemical Physics, 2011, 13, 518)。结果表明对未接枝的纳米颗粒分散，理论上存在一个最佳的界面相互作用来实现其均匀分散，太强或太弱的界面相互作用都会导致一定程度的聚集。这与Schweizer等人采用聚合物参考作用点模型(polymer reference interaction site model, PRISM)研究纳米颗粒在聚合物中分散的结论是一致的(Macromolecules, 2005, 38, 8858)。对表面接枝改性的纳米颗粒也存在一个最佳的接枝密度(grafting density)来实现其均匀分散。同时通过分子模拟发现界面区不存在 “聚合物玻璃化层” (polymer glassy layer)。纳米颗粒对弹性体分子链力学性能增强的机理来自于两个方面，一个是拉伸过程中纳米颗粒诱导分子链的高度去向，另一个是在大变形下搭接在相邻纳米颗粒之间形成的桥链的有限链伸长(limited extensibility)。该成果促进了从整体上去理解与把握其结构与性能间的定量关系。这些文章被包括Progress in Polymer Science, Nanotechnology, Journal of Materials Chemistry, Soft Matter与Macromolecules等引用。

(d)通过计算机模拟与实验研究相结合，考察了炭黑填充丁苯橡胶的杨氏模量，拉伸强度与体积电导率随炭黑体积分数的变化，首次发现了类似于橡胶粒子提高塑料冲击强度的逾渗现象(Physical Chemistry Chemical Physics, 2011, 12, 3014)，。提出了临界粒子间距这一新概念(critical inter-particle distance), 并对纳米颗粒不能有效提高塑料基体的力学性能进行了解释。该文章被包括ACS Nano, Journal of Materials Chemistry与Physical Review E等引用。

(e)基于碳纳米弹簧，纳米环与单层石墨烯的弹性可回复变形，首次将其加入到弹性体网络中，模拟结果表明在良好分散与界面结合的情况下，碳纳米弹簧在有效提高其力学性能的同时，能显著的降低弹性体网络在拉伸-回复过程中的滞后损失(hysteresis loss)(Advanced Functional Materials, 2013, 23, 1156).在当前能源危机的背景下，该发现对有效降低汽车轮胎滚动过程中的滞后损失与油耗有着深远的意义，同时也为碳纳米材料(carbon nano-structured materials)的大规模的工业化提供了一条有效的途径。该研究成果在2013年的APS March Meeting上作为热点新闻被Highlight.

Humanity consumes an enormous amount of energy transporting people and goods. Material science can aid in the quest to make our cars and trucks more energy efficient. Researchers from the Beijing University of Chemical Technology in China added helically shaped carbon nanosprings to rubbery polymers like those found in car tires. The scientists found that the springs significantly reduced energy loss when the polymer deformed and then sprang back to its original shape. Deformation cycles occur when automobile tires travel over bumpy roads and the researchers say incorporating carbon nanosprings into tire materials might significantly improve vehicle fuel efficiency. C31.00009– http://meetings.aps.org/Meeting/MAR13/Event/183563

26. Jun Liu, Jianxiang Shen, Zijian Zheng, Youping Wu, Liqun Zhang, Revealing the toughening mechanism of graphene-polymer nanocomposite through molecular dynamics simulation; Nanotechnology, 26, (291003)2015.

25. Colon-Melendez Laura, Beltran-Villegas Daniel J, van Anders Greg, Jun Liu,  Spellings Matthew, Sacanna Stefano, Pine David J, Glotzer Sharon C, Larson Ronald G, Solomon Michael J, Binding kinetics of lock and key colloids; Journal of Chemical Physics, 142(174909)2015.

24. Maziar Mohammadi, Eric D. Larson, Jun Liu and Ronald G. Larson; Brownian dynamics simulations of coagulation of dilute uniform and anisotropic particles under shear flow spanning low to high Peclet numbers; Journal of Chemical Physics; 142, 024108(1-16)(2015).

23. Jun Liu, Liqun Zhang, Editorial corner - a personal view Proper molecular level tool to explore the structure-property relationships in elastomer nanocomposites; Express Polymer Letters, 9, (582-582)2015.

22. Yangyang Gao, Dapeng Cao, Jun Liu*, Jianxiang Shen, Youping Wu, Liqun Zhang;  Molecular dynamics simulation of the conductivity mechanism of nanorod filled polymer nanocomposites; Physical Chemistry Chemical Physics; 17,(22959-22968)2015.

21. Jianxiang Shen, Jun Liu, Haidong Li, Liqun Zhang, Molecular dynamics simulations of the structural, mechanical and visco-elastic properties of polymer nanocomposites filled with grafted nanoparticles, Physical Chemistry Chemical Physics; 17,( 7196-7207)2015.

20. Jun Liu, Jianxiang Shen, Yangyang Gao, Huanhuan Zhou, Youping Wu, Liqun Zhang*; Detailed simulation of the role of functionalized polymer chains on the structural, dynamic and mechanical properties of polymer nanocomposites; Soft Matter; 10, 8971-8984(2014).

19.Yangyang Gao, Jun Liu*, Jianxiang Shen, Youping Wu, Liqun Zhang*; Influence of various nanoparticle shapes on the interfacial chain mobility: a molecular dynamics simulation; Physical Chemistry Chemical Physics; 16, 21372-21382(2014).

18.Yangyang Gao, Jun Liu*, Jianxiang Shen, Dapeng Cao, Liqun Zhang*; Molecular dynamics simulation of the rupture mechanism in nanorod filled polymer nanocomposites; Physical Chemistry Chemical Physics, 16, 18483-18492(2014).

17. Jun Liu, Larson RG*; Brownian dynamics method for simulation of binding kinetics of patterned colloidal spheres with hydrodynamic interactions; Journal of Chemical Physics; 138, 174904(1-10)(2013).

16. Jun Liu, Yong-Lai Lu, Ming Tian, Fen Li, Jianxiang Shen,  yangyang Gao, Liqun Zhang*; The Interesting Adjusting of "Nanospring" on the Viscoelasticity of Elastomeric Polymer Materials: Simulation and Experiment; Advanced Functional Materials; 2013,23, 1156.

15. Jun Liu, Liqun Zhang*, Dapeng Cao, Jianxiang Shen, yangyang Gao; Computational simulation of elastomer nanocomposites: current progress and future challenges; Rubber Chemistry and Technology; 2012, 85, 450-481. (An invited review)

14. Jun Liu, Yangyang Gao, Liqun Zhang*, Dapeng Cao*; Nanoparticle Dispersion and Aggregation in Polymer Nanocomposites: A Molecular Dynamics Simulation; Langmuir, 2011, 27, 15213.

13. Jun Liu,Wu Yan, Jianxiang Shen, yangyang Gao, Liqun Zhang*, Dapeng Cao*; Polymer-nanoparticle interfacial behavior revisited: A molecular dynamics study;Physical Chemistry Chemical Physics, 2011, 13, 13058.

12.Jun Liu,Sizhu Wu, Liqun Zhang*, Dapeng Cao*, Wenchuan Wang;Molecular dynamics simulation for insight into microscopic mechanism of polymer Reinforcement;Physical Chemistry Chemical Physics, 2011, 13, 518.

11.Jun Liu, Dapeng Cao*, Liqun Zhang*; Static and dynamic properties of model elastomers with various cross-linking densities: A molecular dynamics study; Journal of Chemical Physics, 2009,  131, 034903.

10.Jun Liu, Dapeng Cao*, Liqun Zhang*, Wenchuan Wang; Time-Temperature and Time-Concentration Superposition of Nanofilled Elastomers: A Molecular Dynamics Study; Macromolecules, 2009,  42, 2831.

9.Jun Liu, Dapeng Cao*, Liqun Zhang, Wenchuan Wang*; Static, rheological and mechanical properties of polymer nanocomposites studied by computer simulation; Physical Chemistry Chemical Physics, 2009, 11, 11365. (An invited perspective)

8. Jun Liu, Sizhu Wu, Dapeng Cao*, Liqun Zhang*; Effects of pressure on structure and dynamics of model elastomers: A molecular dynamics study; Journal of Chemical Physics, 2008, 129, 154905.

7. Jun Liu, Dapeng Cao*, Liqun Zhang*; Molecular Dynamics Study on Nanoparticle Diffusion in Polymer Melts: A Test of the Stokes-Einstein Law; Journal of Physical Chemistry C, 2008, 112, 6653.

6. Zhenhua Wang, Jun Liu(contributing equally with the first author), Sizhu Wu, Wenchuan Wang, Liqun Zhang*, Novel percolation phenomena and mechanism of strengthening elastomers by nanofillers; Physical Chemistry Chemical Physics, 2010, 12, 3014.

5. Jianxiang Shen, Jun Liu, Yangyang Gao, Cao Dapeng*, Liqun Zhang*; Revisiting the Dispersion Mechanism of Grafted Nanoparticles in Polymer Matrix: A Detailed Molecular Dynamics Simulation; Langmuir, 2011, 27, 15213.

4. Zhenhua Wang, Yong-Lai Lu, Jun Liu, Zhi-Min Dang, Liqun Zhang*; Preparation of nanoalumina/EPDM composites with good performance in thermal conductivity and mechanical properties, Polymers for Advanced Technologies, 2011, 22, 2302.

3. Zhenhua Wang, Yong-Lai Lu, Jun Liu, Zhi-Min Dang, Liqun Zhang*; Preparation of Nano-Zinc Oxide/EPDM Composites with Both Good Thermal Conductivity and Mechanical Properties, Journal of Applied Polymer Science, 2011, 119, 1144.

2. Xiaohui Wu, Yiqing Wang, Jun Liu, Liqun Zhang*, Improved crack growth resistance and its molecular origin of natural rubber/carbon black by nanodispersed clay; Polymer Engineering and Science, 2012, 52, 1027.  

1. 刘军, 王振华, 吴丝竹, 卢咏来, 张立群,  橡胶纳米补强中的逾渗机理和界面相互作用的研究, 橡 胶工业, 2011, 58, 133.

1. 刘军，张立群；邀请报告; 绿色轮胎用弹性体纳米复合材料全链条与跨尺度基础科学问题；第116期“双清论坛”,中国北京；2014年7月。

2. Jun Liu, Liqun Zhang; Invited Speaker; Elucidating and tuning the non-linear behavior of elastomer nanocomposites through molecular dynamics simulation;  The 3rd International Conference on Nanomechanics and Nanocomposites (ICNN-3); Hongkong, China, May 2014.

3. Jun Liu, Liqun Zhang; Invited Speaker; Molecular dynamics simulation of elastomer nanocomposites: current achievements and future opportunities; 30^th International Conference of The Polymer Processing Society(PPS-30); Cleveland, Ohio, USA, July 2014.

4. Jun Liu, Larson RG; Oral Presentation; Brownian Dynamics method for simulation of recognition kinetics between lock and key colloids; the 86^th ACS Colloid and Surface Science Symposium; Baltimore, Maryland, June 2012.

5. Jun Liu, Larson RG; Oral Presentation; Brownian Dynamics Simulation of Recognition Kinetics Between Lock and Key Colloidal Particles; AICHE annual   meeting; Pittsburgh, Pennsylvania, October 2012.

6. Jun Liu, Larson RG; Oral presentation; Brownian dynamics method for simulation of binding kinetics of patterned colloidal spheres with hydrodynamic interactions; the 84^th Annual Meeting of the Society of Rheology; Pasadena, California, February 2013.

7. Jun Liu, Liqun Zhang, Dapeng Cao; Oral Presentation; The Interesting Influence of Nanosprings on the Viscoelasticity of Elastomeric Polymer Materials: Simulation and Experiment; 2013 APS March meeting; Baltimore, Maryland, March 18-22, 2013.

8. Jun Liu, Dapeng Cao, Liqun Zhang; Oral Presentation; Tuning the mechanical  and visco-elastic properties of elastomer nanocomcoposites: a molecular dynamics simulation; 2013 CCCM-1; Beijing, China, September 10-13, 2013.

9. Jun Liu, Dapeng Cao, Liqun Zhang; Oral Presentation; Tuning the mechanical and visco-elastic properties of elastomer nanocomcoposites: a molecular dynamics simulation; 2013 Joint Symposium about soft matter of Beijing University of Chemical Technology and University of Cambridge；Beijing, China, September 25, 2013.