Long Chain Molecules in the Molten State: Surface Adsorption, Near Surface Structure, and Mutual-Diffusion

<p>The surface segregation in a binary mixture of polymer due to surface energy difference or end-grafting is studied. The surface energy difference induced segregation is compared with the mean-field theory. The end-labeling of chains strengthens the ability of the chain to bind to the surface, and the stretching of the end grafted chains is proved to be a controlling fact limiting the brush density. The structure of a chain near a surface needs to be known in order to make more quantitative analysis. Such knowledge is currently not available although a reflecting surface model is proposed.</p> <p>We also studied the mutual-diffusion of compatible linear chains. It is observed that the broadening of the interfacial width scales as the 1/4 power of the diffusion time for a time scale much longer than the reptation time. It is speculated that the anomalous behavior is either due to small molecular residue in the sample or due to the long chain nature of the polymer itself. If the former possibility can be ruled out, the validity of applying the reptation model to polymer diffusion over small distances might be under challenge.</p> <p>Dynamic secondary ion mass spectrometry (SIMS) is an established technique and its application in polymer science has been around for quite some time. However, the quantitative application in depth profiling was so far not very successful. The technique is reviewed and procedures that ensure correct extraction of depth profiles from raw SIMS data are discussed.</p>

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Physics

Grantor

The Graduate School and University Center of The City University of New York

Year dc:date.available

1993

Author dc:creator

• Zhao, Xiaofeng

Advisors dc:contributor.advisor

• Miriam H. Rafailovich (Advisor)
• Azriel Z. Genach (Chair of Examining Committee)

Committee members dc:contributor.committeemember

• Jonathan C. Sokolov
• Steven A. Schwarz
• Ronald Dickman

• Physics

Repository record dc:identifier

https://academicworks.cuny.edu/gc_etds/1644

OAI identifier oai:identifier

oai:academicworks.cuny.edu:gc_etds-2664