Diffusion of Benzene through Poly(γ-benzyl L-glutamate)

Abstract

Permeability of benzene through polyfy-benzyl L-glutamate) (PBLG) film was found to be dependent on the solvent used for casting the membrane. Thin films of PBLG were cast from methylene chloride and benzene solutions. Permeability of benzene (liquid) through these membranes was measured at different concentrations of benzene, using heptane as diluent. Although the solubility coefficient of the film cast from benzene was only -~18% higher than that of the film cast from methylene chloride (densities being identical), the diffusion coefficient of benzene at infinite dilution, D0, of the former film exceeded that of the latter one by ~550%. These data indicate differences in the morphology of the membranes. The origin of these differences has been related to the different lyotropic solutions (cholesteric in the case of PBLG in methylene chloride and probably smectic in the other case) from which these films were cast.

Preparation and Properties of Phospholipid-Modified Polypeptide

“…Permeability of Na + and K + Ions to Cast Film. Some papers , on the transport properties of small molecules through synthetic polypeptides of rodlike, α-helical structure have been published. The studies on poly( n -alkyl- l -glutamate) 21,22 indicate that the diffusion of small molecules in polypeptide occurs through the side-chain region between helices.…”

“…Some papers 21,22 on the transport properties of small molecules through synthetic polypeptides of rodlike, R-helical structure have been published. The studies on poly(n-alkyl-L-glutamate) 21,22 indicate that the diffusion of small molecules in polypeptide occurs through the side-chain region between helices. Moreover, biomembranes consist of a continuous nonpolar hydrocarbon matrix from the phospholipid bilayer substantially impermeable to most polar substances and protein molecules capable of reversibly binding specific substrates and of transporting them across the membrane even against a concentration gradient.…”

Oriented Thin Film Formation by Surface Graft Polymerization of γ-Methyl l-Glutamate N-Carboxyanhydride in the Melt

“…The properties of these very thin grafted layers can be tuned very easily by functionalization of the glutamic acid monomer unit. Numerous LB studies indicated the applicability of polyglutamates in chemical sensors 12 and membranes for transport of ions, 13,14 electrons, 15,16 and other small molecules 17,18 to mimic biological functions. The optical activity of many polyglutamates 19 can lead to applications in the fields of waveguides, 20 data storage, 21,22 and nonlinear optics.…”

“…The properties of these very thin grafted layers can be tuned very easily by functionalization of the glutamic acid monomer unit. Numerous LB studies indicated the applicability of polyglutamates in chemical sensors and membranes for transport of ions, , electrons, , and other small molecules , to mimic biological functions. The optical activity of many polyglutamates can lead to applications in the fields of waveguides, data storage, , and nonlinear optics. , Recently, Whitesell and Chang published the polymerization of alanine NCAs initiated by amine-functionalized gold substrates, producing highly ordered polymeric films with α-helices oriented nearly perpendicular to the surface.…”