Ultrasonic measurements of membranes and membrane-associated proteins are reviewed. Ultrasonic properties reflect the modulus of membranes and reveal the magnitude and relaxation time of their structural fluctuation. The measurements of lipid bilayers indicated the critical softening as well as the critical slowing down in the vicinity of the gel-to-liquid crystal transition, leading to the conclusion that this phase transition is very near to the second order transition. The relaxation time of the critical structural fluctuation was as long as 100 nsec. The bulk modulus of membranes increased linearly with the increase of the protein content of membranes. The extrapolation of the bulk modulus to 100% of the protein content was 4X10¹⁰ dyn/cm², which has to be the bulk modulus of membrane protein. This value is in good agreement with the bulk modulus of soluble globular proteins. The frequency dependence of the ultra sonic properties indicated that there is no structural relaxation in the ultrasonic frequency region.

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Gas permeation and sorption in amorphous polymers above their glass transition temperature are adequately described by Henry's and Fick's laws. However, below the glass transition temperature, sorption is apparently composed of two mechanisms, the first described by Henry's law dissolution and the second by Langmuir's law of adsorption, known as the “dual sorption model”. The Langmuir mechanism evidently arises from the non-equilibrium nature of the glassy state and the capacity of Langmuir mode of sorption is related to the unrelaxed volume in the glassy state. Molecules sorbed by this mode have less diffusional mobility than molecules sorbed by the Henry's law mode. Because of these differences, the analyses of transient permeation expriments are more complex for glassy polymes compared to those used widely for rubbery polymers. The “dual mobility model” for transport of gases in glassy polymers is developed here which has been successfully used to interpret the observed dependence of the apparent permeability and diffusion coefficient on upstream gas pressure. The state of knowledge about gas permeation and sorption in glassy polymers is reviewed. It is seen that such observations provide a new approach to probe the physical structure of the glassy state.

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Photocontrol of polypeptide conformation was attempted by using polyaspartates containing azobenzene moieties in their side chains. It was found by circular dichroism (CD) measurements that trans-cisphotoisomerization causes conformational changes such as left-handed α-helix→right-handed α-helix and left-handed α-helix→random coil. The photoresponsive behavior was remarkably solvent dependent, marked conformational changes being induced in the mixed solvents of adequate solvent compositions. The polyaspartates showed no photoinduced conformational change in the solid films although heating caused conformational transitions.

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The sign of the membrane potentials across poly (vinyl chloride) /crown ether membrane was controlled by changing the direction from which UV light was irradiated to the membrane. The results were explicated in terms of the asymmetric distribution of the photo-generated cis form of the crown ether in the membrane.

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The behaviors of bi-active layer membrane composed of hydrophilic and hydrophobic polymers in pervaporation are studied with organic mixtures. It is shown that the component of the permeate is different when the mixture permeate this membrane from one face or the other.

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Reverse osmosis separation for inorganic ions were examined by anionic and cationic charged membranes. The solute permeation was carried out in single-solute aqueous solution (300 mg/l) under applied pressure of 80kg/cm²at 20°C.
In case of anionic charged membranes, the rejection of counter-ions (alkali cations) with common anion Cl- increased with the crystal ionic radius. The rejection of bi-valent cations were lower than one of uni-valent cations. The rejection of co-ions (halogen anions) with common cation Na⁺ increased with decrease in the crystal ionic radius.
In case of cationic charged membranes, the rejection of counter-ions (halogen anions) with common cation Na⁺ increased with decrease in the crystal ionic radius and with increase in enthalpy for hydration of ion. The rejection of co-ions (alkali cations) with common anion Cl^- increased with decrease in the crystal ionic radius. The rejection of bi-valent cations were higher than one of uni-valent cations.
From these facts, operated factors in reverse osmosis separation of inorganic ions by charged membranes were discussed.

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Reverse osmotic concentration of aqueous 1, 2 propanediol solution was carried out, using cellulose acetate asymmetric membranes and composite membranes, PEC-1000, NS-100, and FT-30. Separation of 1, 2 propanediol and flux through the membranes were measured within the following ranges : concentration; 1 to 10 wt%, operating presssres; 3.92 to 6.86 MPa.
PEC-1000 membrane shows the best performance among the membranes tested. Its separation at 5wt% and 4MPa was above 99% At the same experimental condition, separation of FT-30 BWwas 89%, FT-30 SW 89%, NS-100 90%, and cellulose acetate heat treated at 90°C 92%, at 87°C 87%, and at 85°C 79%.
An analysis of data with Spiegler-Kedem's transport model was carried out to obtain membrane constants such as reflection coefficient σ, solute and hydraulic permeabilitics ω and L_p, concentration induced compaction coefficients for ω and L_p, β_s and β_v. Values of σ for composite membranes are 1.0, but for cellulose acetate less than 1.0. PEC-1000 shows the largest value of β_v, then FT-30, NS-100, and cellulose acetate shows the smallest.
Energy and membrane area required using the best membrane PEC-100 were calculated to concentrate 1, 2 propanediol from 1.8 wt% to 16 and 12 wt% by reverse osmosis. The energy per one kilogram of concentrated 1, 2 propanediol is proportional to the operating pressure and slightly depends on final concentration and concentration polarization, and is found 0.1 to 0.18 kWh. The membrane area is inversely proportional to the operating pressure and found 0.15, 0.25 and 0.65 m²/kg 1, 2 propanediol/day for 10, 8 and 5 MPa at no concentration polarization.

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