@article {4742,
	title = {Size exclusion chromatography does not require pores},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {97},
	number = {13},
	year = {2000},
	note = {ISI Document Delivery No.: 327UHTimes Cited: 16Cited Reference Count: 24},
	month = {Jun},
	pages = {7064-7067},
	type = {Article},
	abstract = {Separation of macromolecules on the basis of their molecular weight by size exclusion chromatography has long been considered to be caused by the geometry-dependent partition of macromolecules between a continuous phase and the porous interior of a gel or cross-linked bead. The volume of a pore accessible to a solute is limited by its relative dimensions, so larger molecules will have access to a smaller volume and will remain in a bead for a shorter time than smaller solutes. Our recent alternate picture proposes that the partition coefficient can be calculated from a thermodynamic model for the free energy of mixing of the solute with the gel phase. Size-dependent exclusion caused by the unfavorable entropy of mixing associated with the partition is predicted; the magnitude of the effect is modified by enthalpic: interactions between the solute and the gel phase. This concept is extended here to describe the partition of macromolecules into a layer of terminally attached polymer chains grafted onto a solid bead. Both simple mean field and self-consistent field theory calculations predict size-dependent entropic exclusion, Experimental results obtained with neutral polymer chains grafted onto solid polystyrene latex beads confirm the predictions.},
	keywords = {CHAINS, MODEL},
	isbn = {0027-8424},
	url = {<Go to ISI>://000087811600027},
	author = {Brooks, D. E. and Haynes, C. A. and Hritcu, D. and Steels, B. M. and Muller, W.}
}
@article {3703,
	title = {Interfacial thickness of liposomes containing poly(ethylene glycol)-cholesterol from electrophoresis},
	journal = {Biophysical Journal},
	volume = {70},
	number = {1},
	year = {1996},
	note = {ISI Document Delivery No.: TY683Times Cited: 29Cited Reference Count: 33},
	month = {Jan},
	pages = {313-320},
	type = {Article},
	abstract = {The electrophoretic mobilities of liposomes incorporating a polyethylene glycol (PEG) headgroup coupled to cholesterol for PEG of average chain index 3.0, 13.2, and 22.3 have been determined as a function of PEG-cholesterol mole fraction between 5\% and 40\% and ionic strength between 2 and 200 mM. The liposome compositions were 40 mole \% cholesterol plus PEG-cholesterol, 10 mole \% 1,2-dipalmitoyl-sn-glyerco-3-phosphoglycerol and 50 mole \% egg phosphatidylcholine. The mobilities were fit to a model in which the PEG forms a surface layer of polymer subject to viscous drag arising I from electroosmotic flow within this layer. The model provides estimates of the average layer thickness that are comparable to those determined from contemporary models of surface-attached polymer.},
	keywords = {CELLS, CHAINS, grafted polymer brush, mobility, PARTICLES},
	isbn = {0006-3495},
	url = {<Go to ISI>://A1996TY68300026},
	author = {Janzen, J. and Song, X. and Brooks, D. E.}
}
