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Jun 26 Niraj Ghimire- Density Matrix Renormalization Group studies of interacting dipoles in a zigzag chain- Ph. D. defense11:00am

Niraj Ghimire- Density Matrix Renormalization Group studies of interacting dipoles in a zigzag chain- Ph. D. defense

Wednesday, June 26th, 2019

11:00 AM - 01:00 PM

Storrs Campus
Gant West Room 103-A

Dissertation Defense

Niraj Ghimire
Physics Department
University of Connecticut

“Density Matrix Renormalization Group studies of interacting dipoles in a zigzag chain”

The goal of my research is to simulate quantum mechanics, which is known to be a very challenging problem even for the most advanced supercomputers of today. The system I have chosen consists of molecular dipoles in a quasi-one-dimensional optical lattice. For the first part of the talk, I will discuss the situation where the dipoles are polarized in the plane of the lattice at half-filling and double occupancy is not allowed on any lattice sites. The dipoles can hop around between sites and the interactions between them can be attractive or repulsive, with the hopping and interaction allowed up to second neighbors. I am particularly interested in the zero-temperature quantum phases induced by geometrical frustration, a situation where not all the interactions are satisfied. By mapping the dipoles in this lattice to a spin-1/2 model and by using the numerical approximation method known as density matrix renormalization group (DMRG), I have studied this system and produced a complex phase diagram.

For the second part of the talk, I will discuss the situation where a dipole is trapped in each lattice site such that the dipole moment vector can be oriented in any direction. The dipoles interact with one another via dipole-dipole potential and also interact with the external field, but they do not hop around between lattice sites. I will talk about some results for this classical model. Then I will explain how I have mapped it to a spin-2 model (which is quantum mechanical) and explain some results obtained using DMRG.

Major Advisor: Dr. Susanne Yelin
Wednesday, June 26, 2019
11:00 AM
Gant Science Complex
GW-103A

Contact Information: Susanne Yelin
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Jun 27 MCB PSM PIE Fellows Program Workshop II9:00am

MCB PSM PIE Fellows Program Workshop II

Thursday, June 27th, 2019

09:00 AM - 05:00 PM

Storrs Campus
Beach Hall 204

Sequencing and Analyzing the Microbiome - Partnership in Innovation & Education (PIE) Fellows learn how to use PCR to amplify 16S rRNA, prepare libraries for sequencing on an Illumina MiSeq, identify microbes present in the samples, and prepare figures. Instructors are Dr. Joerg Graf, Danielle Lesperance, and Todd Testerman. Funded through UConn Provost Office, UConn Department of Molecular and Cell Biology (MCB) Professional Science Master's (PSM) Programs, and Connecticut Innovations CTNext Initiative in Higher Education.

Contact Information: elaine.mirkin@uconn.edu
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Jun 28 MCB PSM PIE Fellows Program Workshop II9:00am

MCB PSM PIE Fellows Program Workshop II

Friday, June 28th, 2019

09:00 AM - 05:00 PM

Storrs Campus
Beach Hall 204

Sequencing and Analyzing the Microbiome - Partnership in Innovation & Education (PIE) Fellows learn how to use PCR to amplify 16S rRNA, prepare libraries for sequencing on an Illumina MiSeq, identify microbes present in the samples, and prepare figures. Instructors are Dr. Joerg Graf, Danielle Lesperance, and Todd Testerman. Funded through UConn Provost Office, UConn Department of Molecular and Cell Biology (MCB) Professional Science Master's (PSM) Programs, and Connecticut Innovations CTNext Initiative in Higher Education.

Contact Information: elaine.mirkin@uconn.edu
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Jul 1 MCB PSM PIE Fellows Program Workshop II9:00am

MCB PSM PIE Fellows Program Workshop II

Monday, July 1st, 2019

09:00 AM - 05:00 PM

Storrs Campus
Beach Hall 202

Sequencing and Analyzing the Microbiome - Partnership in Innovation & Education (PIE) Fellows learn how to use PCR to amplify 16S rRNA, prepare libraries for sequencing on an Illumina MiSeq, identify microbes present in the samples, and prepare figures. Instructors are Dr. Joerg Graf, Danielle Lesperance, and Todd Testerman. Funded through UConn Provost Office, UConn Department of Molecular and Cell Biology (MCB) Professional Science Master's (PSM) Programs, and Connecticut Innovations CTNext Initiative in Higher Education.

Contact Information: elaine.mirkin@uconn.edu
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Jul 3 Chemistry Colloquium: Si Wu, University of Science and Technology of China10:15am

Chemistry Colloquium: Si Wu, University of Science and Technology of China

Wednesday, July 3rd, 2019

10:15 AM - 11:30 AM

Storrs Campus
CHEM A304

Chemistry Colloquium: "Controlling Polymers with Light"

Dr. Si Wu, Department of Polymer Science and Engineering, University of Science and Technology of China
Host: Dr. Jie He

In this talk, I will present synthesis of photoresponsive polymers and controlling their properties and functions with light. My talk contains three parts. In the first part, I will show you that light can switch the glass transition temperature (Tg) of azobenzene-containing polymers (azopolymers) and induce reversible solid-to-liquid transitions of the polymers. [1,2] The azobenzene groups in the polymers exhibit reversible cis-trans photoisomerization. Trans azopolymers are solids with Tg above room temperature, whereas cis azopolymers are liquids with Tg below room temperature. Because of the photoinduced solid-to-liquid transitions of these polymers, light can repeatedly heal cracks in azopolymers, reduce the surface roughness of azopolymer films, and control the adhesion of azopolymers for transfer printing. In the second part, I will introduce red-light-responsive Ru-containing polymers and their applications in phototherapy and reconfigurable materials. [3-5] We synthesized Ru-containing block copolymers (BCPs). The Ru moieties act as light-cleavable groups , singlet oxygen sensitizers and anticancer agents. The BCPs assembled into micelles, vesicles, large compound micelles and other nanostructures. The BCP assemblies can be taken up by cancer cells. Red light can pass through tissue and activate the Ru-containing BCP assemblies. The photoactivated Ru-containing BCP assemblies can inhibit the growth of cancer cells. Photoresponsive Ru complexes were also used to construct reconfigurable surfaces . In the third part, I will present near-infrared light induced release and ligation of polymers assisted by upconverting nanoparticles (UCNPs). [6-8] UCNPs convert NIR light to UV or visible light that can trigger photoreactions Thus, near-infrared light-responsive materials can be fabricated using UCNPs.

References
[1] H. Zhou, C. Xue, P. Weis, Y. Suzuki, S. Huang, K. Koynov, G. K. Auernhammer, R. Berger, H.-J. Butt, S. Wu, Nature Chemistry 2017, 9, 145
[2] W.-C. Xu, S. Sun, S. Wu, Angew. Chem. Int. Ed. 2019, in press
[3] W. Sun, S. Li, B. Haupler, J. Liu, S. Jin, W. Steffen, U. S. Schubert, H. J. Butt, X. J. Liang, S. Wu, Adv. Mater. 2017, 29, 1603702
[4] W. Sun, Y. Wen, R. Thiramanas, M. J. Chen, J. X. Han, N. Q. Gong, M. Wagner, S. Jiang, M. S. Meijer, S. Bonnet, H. J. Butt, V. Mailander, X. J. Liang, S. Wu, Adv. Funct. Mater. 2018, 28, 1804227
[5] C. M. Xie, W. Sun, H. Lu, A. Kretzschmann, J. H. Liu, M. Wagner, H. J. Butt, X. Deng, S. Wu, Nature Communications 2018, 9, 3842
[6] S. Wu, H.-J. Butt, Adv. Mater. 2016, 28, 1208
[7] P. Lederhose, Z. Chen, R. Mueller, J. P. Blinco, S. Wu, C. Barner-Kowollik, Angew. Chem. Int. Ed. 2016, 55, 12195
[8] Z. Chen, S. He, H. J. Butt, S. Wu, Adv. Mater. 2015, 27, 2203

Refreshments will be served at 10:15am. All are welcome.

Contact Information: jie.he@uconn.edu
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EDUCATION
The Institute of Materials Science (IMS) supports over 100 graduate students in three primary fields of study, Materials Science and Engineering, Polymer Science, and Materials Science. In addition, graduate students in affiliated departments use IMS facilities to perform materials-related research.

RESEARCH
IMS provides superior graduate research education in the interdisciplinary fields of materials science and engineering, and provides materials-related technical outreach to Connecticut’s industries. IMS operates and maintains extensive state-of-the-art instrumentation including a wide range of laboratories. Support facilities include an electronics shop and an instrument and machine shop.

Over 100 faculty members from twenty departments including the UConn Health Center are affiliated with IMS, contributing to the Institute’s interdisciplinary research programs. Primary disciplines represented are chemistry, physics, chemical engineering, materials science and engineering, polymer science, pharmacy, molecular and cell biology, mechanical engineering, electrical engineering, biomaterials, and biosciences.

OUTREACH
The Institute is also home to the Industrial Affiliates Program, an industry outreach program which assists Connecticut companies in their research and development efforts to improve new and existing products. The Industrial Affiliates Program provides many benefits for member companies, including access to facilities and faculty at UConn, short courses, and other resources that can assist in materials-related problem solving for industry.