crystallization

1. crystallization Silk Polymer Models for Structure-Function RelationshipsDavid Kaplan and Peggy Cebe, Tufts University - DMR-0402849 Background - Silk is a protein, a natural biopolymer, produced by silkworms and spiders that is formed into fibers with remarkable mechanical properties. Silk has similarities to synthetic polymers, including the ability to crystallize (beta sheet formation). The process of crystallization directly impacts mechanical properties and our ability to form new high performance materials from these proteins. Objective – To control the crystallization process of silk in order to better understand both the natural silk fiber formation process as well as to elucidate new approaches outside the organisms to form useful new materials from this protein. Figure - Depicts the fraction of beta sheet crystals formed during crystallization at two different temperatures, 198.8C (red) and 193.8C (blue). Crystals grow more quickly, and the amount formed is larger, at higher temperature. Insert illustrates the process of crystallization of the protein chains.

2. a Profs. Kaplan and Cebe provide research opportunities and mentoring for students interested in careers in science and engineering. a) High School student in Prof. Kaplan’s laboratory. b) During Career Day, Ryan (r) asks Prof. Kaplan (l) a question through the American Sign Language interpreter. c.) Prof. Cebe helps Jennifer, an REU summer student, performing thermal analysis. d.) An REU summer student in Prof. Kaplan’s laboratory. c d b Silk Polymer Models for Structure-Function RelationshipsDavid Kaplan and Peggy Cebe, Tufts University - DMR-0402849 Educational Aspects, and Outreach to the Deaf and Hard of Hearing