Squishy Physics

Next seminar: March 29th 2017, 5.30 PM in Pierce 301

Speaker: Prof. Peggy Cebe, Tufts University

Title: Unraveling Mysteries of the Silk Cocoon

 

Abstract:

Silk is a naturally occurring biopolymer which has been used in textiles for over 5000 years. The properties of silk protein are related to the secondary structures, such as helices, random coils and beta pleated sheet crystals. We have prepared the silk protein, fibroin, by extracting it from the native cocoons and use this as a starting material for our investigations into the structure of silk. In this presentation, I will describe our studies to quantify the amounts of the different secondary structures using X-ray diffraction, infrared spectroscopy, and high precision, high accuracy heat capacity measurements. Silk degrades before melting when heated at slow rates. We used fast scanning chip calorimetry to heat silk at 2000 K/s, thereby minimizing thermal degradation and demonstrating the melting behavior of beta pleated sheets. A first estimate of the thermodynamic heat of fusion of beta sheet crystals is presented.

 

Squishy Physics & Pizza Seminar Series

When: Wednesday Evenings - 5:30pm till...

Where: Room 301, Pierce Hall, 29 Oxford St, on the Harvard Campus. Directions and parking instructions are here.

What: These talks are informal, with emphasis on new results and ideas, rather than polished presentations. The Squishy audience members typically include soft matter scientists, physicists, engineers, chemists, and biologists.  The goal is to stimulate discussion with the audience.  Talks are typically about 45 minutes long, with lots of questions along the way.

Pizza: Only the finest! 

How to join the weekly Squishy Physics mailing list: please visit the Signup Page.

Directions: Where: Squishy Physics talks are held in Pierce Hall room 301, 29 Oxford Street, Cambridge, MA. See Harvard Campus map here.

Parking: Metered parking is available on Oxford Street.  Speakers, please contact Jill Susarrey to obtain a parking permit.  

Squishy Physics is sponsored by the Cabot Corporation, Dean Cherry Murray and the Weitz Research Group.

If you have comments or suggestions or would like to give a talk, please contact Liheng Cai or Joerg Werner.

Here is the upcoming schedule