Yao Wang

Publications (5)18.28 Total impact

• Article: An upside down view of cholesterol's condensing effect: does surface occupancy play a role?

  Vaclav Janout, Serhan Turkyilmaz, Minghui Wang, Yao Wang, Yuichi Manaka, Steven L Regen
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  ABSTRACT: The condensing action of cholesterol has been compared with that of a structural isomer having its hydroxyl group located at the C-25 position (i.e., 25-OH'), that is, an isomer favoring an "upside down" orientation in lipid membranes. Surface pressure-area isotherms of mixed monolayers made from 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/cholesterol and DMPC/25-OH' have established that 25-OH' has a weaker condensing effect than cholesterol. Nearest-neighbor recognition measurements in liposomes made from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) have also shown that 25-OH' has a weaker condensing effect in the physiologically relevant fluid bilayer state. These findings provide support for surface occupancy playing a role in the condensing action of cholesterol.
  Langmuir 03/2010; 26(8):5316-8. · 4.19 Impact Factor
• Article: Creating Poly(ethylene oxide)-Based Polyelectrolytes for Thin Film Construction Using an Ionic Linker Strategy

  Yao Wang, Vaclav Janout, Steven L. Regen
  01/2010;
• Article: Defects in a polyelectrolyte multilayer: the inside story.

  Yao Wang, Erwin Stedronsky, Steven L Regen
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  ABSTRACT: Moderate changes in the concentration of poly(sodium 4-styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) used in fabricating polyelectrolyte multilayers (PEMs) have been found to strongly affect the formation of defects (i.e., gaps) within these films, as revealed by gas permeation selectivity measurements. Thus, PEMs made from 14 alternating layers of PSS and PAH under "high" concentration conditions (15.0 mM in repeat units) exhibit He/N(2) permeation selectivities that are greater than 200. In sharp contrast, analogous films of similar thickness that are made from 24 alternating layers of PSS and PAH under "low" concentration conditions (1.0 mM in repeat units) showed no significant He/N(2) permeation selectivity, reflecting the presence of defects. Analogous PEMs that were fabricated from 14 alternating layers of PSS and PAH, using 1.0 mM PSS and PAH in the presence of added NaCl, where reduced viscosities and polymer conformations were matched with those found under high concentration conditions, exhibited the same thicknesses and very similar barrier properties.
  Journal of the American Chemical Society 01/2009; 130(49):16510-1. · 9.91 Impact Factor
• Article: Probing the gas permeability of an ionically cross-linked Langmuir-Blodgett bilayer with a "touch" of salt.

  Yao Wang, Erwin Stedronsky, Steven L Regen
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  ABSTRACT: The main barrier for gas permeation across ionically cross-linked Langmuir-Blodgett (LB) bilayers, made from a 5,11,17,23,29,35-hexakis[( N, N, N-trimethylamonium)-N-methyl-37,38,39,40,41,42-hexakis-n-hexamedecyloxy-calix[6]arene hexachloride (1) and poly(sodium 4-styrenesulfonate) (PSS), has been determined by measuring the effects of NaCl on the thickness of the PSS layer encased between the calixarene layers and the permeation characteristics of the resulting membrane. Specifically, the fact that NaCl increases the uptake of PSS by the LB film and increases the permeance of these membranes toward N2 and CO2 but not He provides compelling evidence that the main barrier for permeation is the calixarene layers and not the PSS layer that is encased between them. The effects of NaCl on ionic cross-linking, surface pressure, and surface viscosities are discussed.
  Langmuir 07/2008; 24(12):6279-84. · 4.19 Impact Factor
• Article: Polymer-Enhanced Stability of Glued Langmuir−Blodgett Monolayers

  Yao Wang, Vaclav Janout, Steven L. Regen
  01/2008;