Guojun Xie

Graduate Student

Education

Ph. D., Chemistry, Carnegie Mellon University, Pittsburgh, U.S. (GPA: 4.05/4.00)  08/2013-06/2018(expected)
B. S., Chemistry, Peking University, Beijing, P.R. China (GPA: 3.55/4.00)              09/2009-07/2013

Research

Ph.D. Candidate, with Prof. Krzysztof Matyjaszewski, Dept. of Chemistry, Carnegie Mellon University, Pittsburgh, US

 Synthesis and characterization of complex polymeric architectures               08/2013-present

• Designed the chemical structures and synthetic strategies of novel polymeric materials for various application including surfactants, lubricants, (ultra)soft elastomer, porous materials and templates for nanoparticles
• Optimized conditions for atom transfer radical polymerization (ATRP) via kinetic studies
• Performed multi-step syntheses through application of various polymerization techniques and post-polymerization modification methods to achieve targeted materials
• Evaluated the structures and properties of synthesized polymeric using various characterization techniques in inter-department and inter-university collaborations
• Extracted and rationalized the structure-property relations in materials based on analysis of experimental results

Research assistant, with Prof. Yuguo Ma, College of Chemistry, Peking University, Beijing, China 

 Developed heterobimetallic olefin polymerization phenoxy-imine catalysts        09/2012-06/2013

• Synthesized phenoxy-imine ligands with structural diversity for studying and tuning the property of catalysts
• Tested the performance of catalysts by polymerization procedures and polymer characterization

Research assistant, with Prof. Jianbo Wang, College of Chemistry, Peking University, Beijing, China

 Studied transition-metal-catalyzed isomerization of cyclopropene derivatives            09/2010-08/2012

• Synthesized organic substrates with different functional groups to test the functional group tolerance

Publications

• Xie, G.; Pawel, K.; Tilton, R. D.; Matyjaszewski, K. "Heterografted Molecular Brushes as Stabilizers for Water-in-Oil Emulsions" Macromolecules 2017, 50 (7), 2942-2950.
• Xie, G.; Ding, H.; Daniel, W. F. M.; Wang, Z.; Pietrasik, J.; Sheiko, S. S.; Matyjaszewski, K., "Preparation of titania nanoparticles with tunable anisotropy and branched structures from core–shell molecular bottlebrushes". Polymer 2016, 98, 481-486.
• Daniel, W. F. M.; Xie, G.; Vatankhah Varnoosfaderani, M.; Burdyńska, J.; Li, Q.; Nykypanchuk, D.; Gang, O.; Matyjaszewski, K.; Sheiko, S. S., "Bottlebrush-Guided Polymer Crystallization Resulting in Supersoft and Reversibly Moldable Physical Networks". Macromolecules 2017, 50 (5), 2103-2111.
• Wang, Z.; Pan, X.; Yan, J.; Dadashi-Silab, S.; Xie, G.; Zhang, J.; Wang, Z.; Xia, H.; Matyjaszewski, K., "Temporal Control in Mechanically Controlled Atom Transfer Radical Polymerization Using Low ppm of Cu Catalyst". ACS Macro Letters 2017, 6 (5), 546-549.
• Yuan, R.; Kopeć, M.; Xie, G.; Gottlieb, E.; Mohin, J. W.; Wang, Z.; Lamson, M.; Kowalewski, T.; Matyjaszewski, K. "Mesoporous Nitrogen-doped Carbons from PAN-based Molecular Bottlebrushes" Polymer accepted
• Faivre, J.; Shrestha, B. R.; Burdynska, J.; Xie, G.; Moldovan, F.; Delair, T.; Benayoun, S.; David, L.; Matyjaszewski, K.; Banquy, X., "Wear Protection without Surface Modification Using a Synergistic Mixture of Molecular Brushes and Linear Polymers". ACS Nano 2017, 11 (2), 1762-1769.
• Song, Y.; Ye, G.; Wang, Z.; Kopeć, M.; Xie, G.; Yuan, R.; Chen, J.; Kowalewski, T.; Wang, J.; Matyjaszewski, K., "Controlled Preparation of Well-Defined Mesoporous Carbon/Polymer Hybrids via Surface-Initiated ICAR ATRP with a High Dilution Strategy Assisted by Facile Polydopamine Chemistry". Macromolecules 2016, 49 (23), 8943-8950.
• Ding, H.; Yan, J.; Wang, Z.; Xie, G.; Mahoney, C.; Ferebee, R.; Zhong, M.; Daniel, W. F. M.; Pietrasik, J.; Sheiko, S. S.; Bettinger, C. J.; Bockstaller, M. R.; Matyjaszewski, K., "Preparation of ZnO hybrid nanoparticles by ATRP". Polymer 2016, 107, 492-502.
• Wang, G.; Schmitt, M.; Wang, Z.; Lee, B.; Pan, X.; Fu, L.; Yan, J.; Li, S.; Xie, G.; Bockstaller, M. R.; Matyjaszewski, K., "Polymerization-Induced Self-Assembly (PISA) Using ICAR ATRP at Low Catalyst Concentration". Macromolecules 2016, 49 (22), 8605-8615.
• Yan, J.; Kristufek, T.; Schmitt, M.; Wang, Z.; Xie, G.; Dang, A.; Hui, C. M.; Pietrasik, J.; Bockstaller, M. R.; Matyjaszewski, K., "Matrix-free Particle Brush System with Bimodal Molecular Weight Distribution Prepared by SI-ATRP". Macromolecules 2015, 48 (22), 8208-8218.
• Burdyńska, J.; Xie, G.; Li, Y.; Robertson, B.; Acosta, E.; Matyjaszewski, K.; Sheiko, S. “Molecular Bottlebrushes with bimodal side chain length” Poster session presented at: the 248th ACS National Meeting and Exposition; 2014, August 10-14; San Francisco, California.
• Zhang, H.; Li, C.; Xie, G.; Wang, B.; Zhang, Y.; Wang, J., "Zn(II)- or Rh(I)-Catalyzed Rearrangement of Silylated [1,1′-Bi(cyclopropan)]-2′-en-1-ols". J. Org. Chem. 2014, 79 (13), 6286-6293.
• Zhang, H.; Wang, B.; Wang, K.; Xie, G.; Li, C.; Zhang, Y.; Wang, J., "Pd-Catalyzed ring-opening cross-coupling of cyclopropenes with aryl iodides". Chem. Commun. 2014, 50 (59), 8050-8052.

Leadership and Activities

 Manager of GPC-related instruments, Matyjaszewski Group, Carnegie Mellon Univ.  10/2013-present

• Lead the maintenance team of 3 to ensure the proper operations of all 4 GPC systems which analyzes more than 500 samples each month by monitoring instrument parameters, trouble shooting and replacing consumable parts
• Leaded GPC-related instrumental upgrade within the research group by proposing the purchase plan cost up to 200K dollars, negotiating with suppliers to minimizing the cost-effectiveness ratio of purchased instruments and assembled 6 new GPC analytical systems.
• Regulated the large volume of GPC analysis in a research group with more than 25 members via setting users' rules, providing user training and coordination between users
• Attended bi-weekly meeting of manager committee to discuss potential safety issues and solutions

 President, United Network of Peking University for Alumni Abroad, Peking Univ.   10/2010-06/2013

• Established and maintained sustainable relationship with over 300 alumni in the United Network of Peking University for Alumni Abroad
• Hosted annual banquet for 200 plus students who just graduated from Peking University and would continue their studies abroad each year

Technical Skills

• Characterization techniques: Nuclear Magnetic Resonance (NMR), Gel Permeation Chromatography (GPC/SEC), Dynamic Light Scattering (DLS), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), UV-Vis Spectroscopy, Dynamic Mechanical Analysis (DMA), atom force microscope (AFM), Tensiometer.
• Computer skill: Microsoft Office Suite, Origin, MATLAB, ChemBioDraw, LaTeX, Python