北京化工大學高分子化學與物理專業研究生導師介紹：劉軍

 

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-現在          北京化工大學材料科學與工程學院副教授， C類人才海外引進

2011.7-2013.7      美國密西根大學化學工程專業， 博士后 ，導師：美國工程院院士Ronald Gary Larson

2003.9-2011.6    北京化工大學高分子材料科學與工程專業， 本碩博連讀，導師：第一導師教育部長江學者、國家杰出青年基金獲得者張立群教授; 第二導師教育部新世紀優秀人才支持計劃曹達鵬教授

2015年09月 獲第二屆中國國際復合材料科技大會（CCCM-2）優秀論文獎

2013年09月 北京化工大學C類人才引進啟動基金

2010年10月 獲得中國石化 “英才獎學金”

2010年1月 獲得第十六屆全國復合材料學術會議優秀論文獎

2009年6月 獲得北京化工大學 “十大學術之星”稱號

2009年5月 獲得北京化工大學 “優秀研究生(博士生)” 稱號

2008年11月 獲得日本住友橡膠獎學金

2008年4月 獲得北京化工大學 “優秀研究生(碩士)”稱號

三. 主要研究方向：

為實現高分子納米復合材料具有優異的力學、物理與多功能性能，本人采用實驗與計算機模擬手段相結合的方法，從分子水平上對納米顆粒的特性、分散、界面物理化學結合、大分子鏈物理化學結構來設計制備新型納米復合材料。圍繞這些基礎科學問題，目前以第一作者與通訊作者身份發表論文20余篇，包括Advanced Functional Materials, Macromolecules, Soft Matter, Langmuir, Nanotechnology等國際權威期刊，期間參加學術會議共10次，做口頭報告6次。目前承擔國家自然科學基金一項，國家973兩項，北京市教委兩項，企業項目一項，北京化工大學啟動基金一項，累計共兩百余萬。

(a)通過計算機模擬技術首次考察了納米顆粒在聚合物熔體中的擴散行為，并對Stokes-Einstein定律的正確性進行了檢驗(Journal of Physical Chemistry C, 2008, 112, 6653)。模擬結果發現在納米顆粒尺寸大于分子鏈回轉半徑時( ), Stokes-Einstein方程能準確描述納米顆粒的擴散行為， 而對 時，由于納米顆粒只探測到nano-viscosity而導致 Stokes-Einstein出現較大的偏差。該模擬結果很好的解釋了Mackay等人在實驗上的觀察結果(Nano Letters, 2007, 7, 1276)。 該文章目前已被引用70次，包括Progress in Polymer Science, Chemical Society Reviews, Soft matter, Macromolecules,  Physical Review E等國際著名期刊。

(b)模擬了聚合物納米復合材料體系分子鏈動力學性能，首次發現了納米顆粒對分子整鏈松弛(terminal relaxation)的影響存在時間-溫度-濃度等效性(time-temperature-concentration)的關系(Macromolecules, 2009,  42, 2831)。實驗上在研究炭黑(carbon black)填充的高密度聚乙烯(HDPE)時也證實了該結論(Journal of Rheology, 2009, 53, 1379)。該文章被包括Macromolecules與Soft matter等引用。

(c)系統模擬了納米顆粒與表面接枝高分子鏈改性納米顆粒在聚合物基體中的分散行為與機理(Langmuir, 2011, 27, 7926; 2011, 27, 15213)；聚合物分子鏈與納米顆粒界面物理與化學相互作用(Physical Chemistry Chemical Physics, 2011, 13, 13058)以及首次采用計算機模擬對聚合物納米復合材料的力學性能( )進行了考察(Physical Chemistry Chemical Physics, 2011, 13, 518)。結果表明對未接枝的納米顆粒分散，理論上存在一個最佳的界面相互作用來實現其均勻分散，太強或太弱的界面相互作用都會導致一定程度的聚集。這與Schweizer等人采用聚合物參考作用點模型(polymer reference interaction site model, PRISM)研究納米顆粒在聚合物中分散的結論是一致的(Macromolecules, 2005, 38, 8858)。對表面接枝改性的納米顆粒也存在一個最佳的接枝密度(grafting density)來實現其均勻分散。同時通過分子模擬發現界面區不存在 “聚合物玻璃化層” (polymer glassy layer)。納米顆粒對彈性體分子鏈力學性能增強的機理來自于兩個方面，一個是拉伸過程中納米顆粒誘導分子鏈的高度去向，另一個是在大變形下搭接在相鄰納米顆粒之間形成的橋鏈的有限鏈伸長(limited extensibility)。該成果促進了從整體上去理解與把握其結構與性能間的定量關系。這些文章被包括Progress in Polymer Science, Nanotechnology, Journal of Materials Chemistry, Soft Matter與Macromolecules等引用。

(d)通過計算機模擬與實驗研究相結合，考察了炭黑填充丁苯橡膠的楊氏模量，拉伸強度與體積電導率隨炭黑體積分數的變化，首次發現了類似于橡膠粒子提高塑料沖擊強度的逾滲現象(Physical Chemistry Chemical Physics, 2011, 12, 3014)，。提出了臨界粒子間距這一新概念(critical inter-particle distance), 并對納米顆粒不能有效提高塑料基體的力學性能進行了解釋。該文章被包括ACS Nano, Journal of Materials Chemistry與Physical Review E等引用。

(e)基于碳納米彈簧，納米環與單層石墨烯的彈性可回復變形，首次將其加入到彈性體網絡中，模擬結果表明在良好分散與界面結合的情況下，碳納米彈簧在有效提高其力學性能的同時，能顯著的降低彈性體網絡在拉伸-回復過程中的滯后損失(hysteresis loss)(Advanced Functional Materials, 2013, 23, 1156).在當前能源危機的背景下，該發現對有效降低汽車輪胎滾動過程中的滯后損失與油耗有著深遠的意義，同時也為碳納米材料(carbon nano-structured materials)的大規模的工業化提供了一條有效的途徑。該研究成果在2013年的APS March Meeting上作為熱點新聞被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. 劉軍, 王振華, 吳絲竹, 盧詠來, 張立群,  橡膠納米補強中的逾滲機理和界面相互作用的研究, 橡 膠工業, 2011, 58, 133.

1. 劉軍，張立群；邀請報告; 綠色輪胎用彈性體納米復合材料全鏈條與跨尺度基礎科學問題；第116期“雙清論壇”,中國北京；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.