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oai:www.ideals.illinois.edu:2142/29463 2023-07-10 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

Effect of cross-linking on the diffusion of water, ions and small molecules in hydrogels Aluru, Narayana R. Wu, Yanbin 2012-02-01T00:47:23Z 2014-02-01T11:00:28Z 2011-12 2012-02-01T00:47:23Z 2011-12 Understanding the diffusion of small molecules in hydrogel system is of major importance in a variety of applications including drug delivery systems, tissue engineering and contact lens. Cross-linking density of hydrogels has been commonly used to tune key parameters like mesh size and molecular weight between cross-linkers, in order to change macroscopic properties of hydrogels. In this thesis, molecular dynamics investigations of chemically-cross-linked poly(ethylene glycol) (PEG) hydrogels are reported with the aim of exploring the diffusion properties of water, ions, and rhodamine within the polymer at the molecular level. The water structure and diffusion properties were studied at various cross-linking densities with molecular weights of the chains ranging from 572 to 3400. As the cross-linking density is increased, the water diffusion decreases and the slowdown in diffusion is more severe at the polymer-water interface. The water diffusion at various cross-linking densities is correlated with the water hydrogen bonding dynamics. The diffusion of ions and rhodamine also decreased as the cross-linking density is increased. The variation of diffusion coefficient with cross-linking density is related to the variation of water content at different cross-linking densities. Comparison of simulation results and obstruction scaling theory for hydrogels showed similar trends. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-11-29T19:45:26Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Wu_Yanbin.pdf: 652629 bytes, checksum: a1efb6b356724ef3d00a4b7bc2480381 (MD5) Made available in DSpace on 2012-02-01T00:47:23Z (GMT). No. of bitstreams: 2 Wu_Yanbin.pdf: 651351 bytes, checksum: bd895561ffe119029bc05d8d3619fad7 (MD5) license.txt: 4056 bytes, checksum: 9844b572b89ab156f1d335fb232bccb3 (MD5) Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by William Ingram (wingram2@illinois.edu) on 2012-02-01T00:50:36Z Item is restricted until 2014-02-01T00:50:07Z Item reinstated by Sarah Shreeves (sshreeve@illinois.edu) on 2014-02-01T11:00:28Z Item was in collections: Graduate Theses and Dissertations at Illinois (ID: 204) Dissertations and Theses - Mechanical Science and Engineering (ID: 675) No. of bitstreams: 3 Wu_Yanbin.pdf: 651351 bytes, checksum: bd895561ffe119029bc05d8d3619fad7 (MD5) license.txt: 4056 bytes, checksum: 9844b572b89ab156f1d335fb232bccb3 (MD5) Wu_Yanbin.pdf.txt: 94167 bytes, checksum: d7c81697deba3d3eff2deee501b13eca (MD5) Item released from any restrictions by Sarah Shreeves (sshreeve@illinois.edu) on 2014-02-01T11:00:28Z http://hdl.handle.net/2142/29463 en Copyright 2011 Yanbin Wu Cross-linking Diffusion hydrogel poly(ethylene glycol) rhodamine hydrogen bonding Dissertation / Thesis text Mechanical Sci & Engineering 1917 Mechanical Engineering 0133 University of Illinois at Urbana-Champaign Thesis M.S. PHD:Mechanical Enginerng -UIUC 10KS0133PHD