

@mastersthesis {7351,
	title = {A molecular dynamics study of alkane polymers: {In} polymer melts and at an alkane-water interface},
	year = {2005},
	note = {3183640},
	school = {Rensselaer Polytechnic Institute},
	type = {phdPh.{D}.},
	address = {Ann Arbor},
	abstract = {Theoretical treatment of polymer entanglements is complicated because a precise molecular definition of entanglements is not available. Entanglements can be thought of as topological constraints which act as temporary crosslinks between long polymer chains and thus have direct effect on their rheological properties. Given current simulation methods and limited computational resources molecular simulations of long chain polymers to study entanglements is a very daunting task. Here, we introduce a new methodology that self-consistently maps correlations observed from molecular simulations of oligomers to coarse-grained potential interactions for the simulation of polymeric species and accurately reproduces local chain correlations. We show that the coarse-grained simulations provide a reasonable description of the polyethylene melt structure. We also present an algorithm to translate from a coarse-grained polymer system back to atomistic detail. We use the polymeric structures generated using these methods to study polymer entanglements. We reproduce scaling behaviour of polymer viscosity using a novel polymer chain pulling technique and discuss the implications of our results for entanglements between long chain polymers. The crossover region from unentangled to entangled chains as a function of chain length is identified using this method and in good agreement with experiments. In addition, this method allows us to look at entangled polymer chains at a molecular level to observe the nature of entanglements. Oil/water interfaces play an important role in biological systems and industrial aspects such as drug delivery, food processing and detergents. We present results from atomically detailed molecular dynamics simulation of an octane-water liquid-liquid interface. We specifically focus on water structure, orientation, coordination numbers, and hydrogen bonding at the interface. In addition, we probe the interface through insertions of different nonpolar solutes at various locations in the system. We also study the interfacial activity of additives such as salts and surfactants. We use information theory for bulk systems and entend it to interfacial systems. Interfacial systems also provide excellent model systems to study heat transfer at nanoscopic length scale. A systematic study of thermal transport hydrophobic as well as hydrophilic interfaces is performed.},
	keywords = {0494:Chemistry, 0495:Polymers, 0542:Chemical engineering, Alkane polymers, Applied sciences, Chemical engineering, Chemistry, Molecular dynamics, Polymer melts, Polymers, Pure sciences},
	url = {http://search.proquest.com/docview/305426545?accountid=14270},
	author = {Patel, Harshit A}
}
