Center for Soft Matter and Biological Physics Friday Discussion Meetings

Spring 2019

Organizer: Vinh Nguyen

These meetings occur on Fridays from 4:00pm to 5:00pm in Robeson 304 (unless otherwise indicated)

January 2019
January 4

Friday 4:00pm
304 Robeson Hall

"No CSB Discussion Meeting Scheduled"

Organizer: Vinh Nguyen

January 11

Friday 4:00pm
304 Robeson Hall

"No CSB Discussion Meeting Scheduled"

Organizer: Vinh Nguyen

January 18

Friday 4:00pm
304 Robeson Hall

"No CSB Discussion Meeting Scheduled"

Organizer: Vinh Nguyen

January 25

Friday 4:00pm
304 Robeson Hall
(Flyer)

Center for Soft Matter and Biological Physics Workshop (Location Blacksburg Community Center)

"No Discussion Meeting"

Organizers: William Ducker & Katrina Loan

January 28

"Special Date and Time" Monday 5:30pm
304 Robeson Hall

Student discussion with Dr. Rui Zhang (University of Chicago)

Host: Shengfeng Cheng

February 2019
February 1

Friday 4:00pm
304 Robeson Hall

Student discussion with Dr. Ting Ge (Duke University)

Organizer: Shunsaku Horiuchi

February 8

Friday 4:00pm
304 Robeson Hall

Student discussion with Dr. Daniel Sussman (Syracuse University)

Organizer: Michel Pleimling

February 15

Friday 4:00pm
304 Robeson Hall

Student discussion with Dr. Antonia Statt (Princeton University)

Organizer: Uwe Tauber

February 18

"Special Date and Time" Monday 5:30pm
304 Robeson Hall


Student discussion with Dr. Cihan Nadir Kaplan (Harvard University)

Host: Rana Ashkar

February 22

Friday 4:00pm
304 Robeson Hall

"APS March Meeting Practice"

Organizer: Vinh Nguyen

February 25

"Special Date and Time" Monday 5:30pm
304 Robeson Hall


Student discussion with Dr. Trung Dac Nguyen (Northwestern University)

Host: Daniel Capelluto

March 2019
March 1

Friday 4:00pm
304 Robeson Hall

"Faculty Meeting"

Organizer: Vinh Nguyen

March 8

Friday 4:00pm
304 Robeson Hall

"APS March Meeting" (Boston)

"No discussion meeting scheduled"

Organizer: Vinh Nguyen

March 15

Friday 4:00pm
304 Robeson Hall

"Spring Break continuing ends March 17"

"No CSB Discussion Meeting Scheduled"

Organizer: Vinh Nguyen

March 22

Friday 4:00pm
304 Robeson Hall
(poster)


Organizer: Vinh Nguyen

March 29

Friday 4:00pm
304 Robeson Hall
(poster)

"Faculty Meeting"

"No Discussion Meeting"

Organizer: Vinh Nguyen

April 2019
April 5

Friday 4:00pm
304 Robeson Hall
(poster)

"Faculty Meeting"

:No Discussion Meeting"

Organizer: Vinh Nguyen

April 12

Friday 4:00pm
304 Robeson Hall
(poster)

Nicole Abaid (Biomedical Engineering and Mechanics, Virginia Tech)

"Passive and active sensing in the Vicsek model

While many social animals move in groups using passive senses like vision, bats form very large colonies while using on sonar for navigation. Sonar is a so-called active sense, which relies on a self-generated signal (sound) rather than one already present in the environment (e.g., light for vision). From an engineering perspective, using active sensing in large groups poses many challenges centered around interference between signals produced by peers. However, experimental work with bats suggests that these animals may be capable of using their peers' signals for passive sonar, which may ameliorate some of these complications.  Taking this system as inspiration, we explore the possibility of combining passive and active sensing in a well-studied model which shows collective behavior, the Vicsek model. The Vicsek model enforces a local alignment rule in groups of self-propelled particles perturbed by noise. Phase transition is observed in both the presence and absence of passive sensing, yet the range of parameters for which ordered and disordered group states exist dramatically changes when passive sensing is used. Notably, we find numerous cases of the model for which the implementation of passive sensing increases the robustness of the collective behavior to noise.

Organizer: Vinh Nguyen

April 19

Friday 4:00pm
304 Robeson Hall
(poster)

"Faculty Meeting"

"No Discussion Meeting"

Organizer: Vinh Nguyen

April 26

Friday 4:00pm
304 Robeson Hall
(poster)

Dr. Saptarshi Chakraborty (Physics, Virginia Tech)

"Polymer-Stabilized Colloidal Catalysts: Role of Polymers and Strategies for Recovery and Reuse"

Gold nanoparticles (AuNPs) have attracted enormous attention due to their unique catalytic activities. Colloidal AuNPs provides the benefit of selectivity, greater surface area per mass of catalyst compared to supported catalysts, catalyzes reactions under mild conditions and are very effective for chiral catalysis. On a per metal basis colloidal AuNPs demonstrate higher catalytic activity than their supported counterparts. Colloidal AuNPs however requires surface functionalization with ligands to prevent aggregation which causes surface passivation and significant reduction in catalytic activity. Colloidal AuNP catalytic activity is strongly dependent on ligand packing and conformation on the AuNP surface. Large polymeric ligands demonstrate increase in available surface area leading to increased catalytic activity, while small molecule ligands lead to complete AuNP surface passivation. A major drawback of colloidal AuNPs as catalysts is the catalyst recovery from the product stream. We have employed small pH sensitive ligands as AuNP stabilizers to show that AuNPs can be recovered from the product stream by altering the pH to selectively precipitate or phase transfer catalyst into organic solvents. However, due to the high small molecule packing density on AuNP surface, complete surface passivation was observed. Catalytic activity could be recovered by partially functionalizing the AuNP surface, however at the cost of recoverability. To maintain catalytic activity in recoverable catalysts, we have developed pH sensitive polymer ligands by synthesizing thiolated polymer ligands. AuNPs functionalized with thiolated polymer, demonstrate similar recoverability while retaining high catalytic activity. Application of colloidal AuNP as catalysts, thus entails fine tuning ligand MW, structure, catalytic activity and recoverability.

Organizer: Vinh Nguyen

May 2019
May 3

Friday 4:00pm
304 Robeson Hall
(poster)

Prof. Jonathan Boreyko (Mechanical Engineering, Virginia Tech)

"TBD"

Organizer: Vinh Nguyen

May 8

Wednesday 4:00pm
304 Robeson Hall
(poster)

Classes end


(No CSB Discussion Meeting)

Organizer: Vinh Nguyen

May 10

Friday 4:00pm
304 Robeson Hall
(poster)

Exams Begin


(No CSB Discussion Meeting)

Organizer: Vinh Nguyen

May 17

Friday 4:00pm
304 Robeson Hall
(poster)

University Commencement and College and Department Ceremonies


(No CSB Discussion Meeting)

Organizer: Vinh Nguyen

Center for Soft Matter and Biological Physics Friday Discussion Meetings

Summer 2019

Organizer: Vinh Nguyen

These meetings occur on Fridays from 1:30pm to 2:30pm in Robeson 304 (unless otherwise indicated)

May 2019
May 24

Friday 1:30pm
304 Robeson Hall
(poster)

"CSB Symposium Week"

"No Discussion Meeting"

Host:

May 31

Friday 1:30pm
304 Robeson Hall
(poster)

Ruslan Mukhamadiarov (Physics, Virginia Tech)

"TBD"

Host:

June 2019
June 7

Friday 1:30pm
304 Robeson Hall
(poster)

Host:

June 14

Friday 1:30pm
304 Robeson Hall
(poster)

Ruslan Mukhamadiarov (Physics, Virginia Tech)

"TBD"

Host:

June 21

Friday 1:30pm
304 Robeson Hall
(poster)

James Stidham (Physics, Virginia Tech)

"TBD"

Host:

June 28

Friday 1:30pm
304 Robeson Hall
(poster)

Ruslan Mukhamadiarov (Physics, Virginia Tech)

"TBD"

Host:

July 2019
July 5

Friday 1:30pm
304 Robeson Hall
(poster)

"Last day of Classes of Summer Session I"

No Discussion Meeting

Host:

July 12

Friday 1:30pm
304 Robeson Hall
(poster)

Ruslan Mukhamadiarov (Physics, Virginia Tech)

"TBD"

Host:

July 19

Friday 1:30pm
304 Robeson Hall
(poster)


Host:

July 26

Friday 1:30pm
304 Robeson Hall
(poster)


Host:

August 2019
August 2

Friday 4:00pm
304 Robeson Hall
(poster)

Ruslan Mukhamadiarov
(Physics, Virginia Tech)

"TBD"

Host:

August 9

Friday 1:30pm
304 Robeson Hall
(poster)

Host:

August 16

Friday 1:30pm
304 Robeson Hall
(poster)

"Exams Begins for Summer Session II

Host: