Fibrinogen and lysozyme adsorption on amorphous carbon film surface detected by multilayer device from the back side of the film

To develop hydrogenated amorphous carbon (a-C:H) as a biocompatible coating, a-C:H was studied in terms of its protein adsorption during the initial process of cell adsorption. A multilayer surface plasmon resonance (SPR) device consisting of an a-C:H layer on Au was built in the Kretschmann configuration to detect protein adsorption on an a-C:H film surface. From the dependence of reflectivity on the laser incident angle, SPR angle was determined to the incident angle in which the light intensity was reduced drastically. The proteins considered were lysozyme (Lyz) and fibrinogen (Fib). The SPR angle increased from 58.09 to 58.69° upon the adsorption of Lyz when the nonadsorbed Lyz was removed after introduction of 20 μM Lyz-containing solution. Upon the adsorption of Fib, the SPR angle increased from 60.95 to 61.76° when the nonadsorbed Fib were removed after the introduction of 0.4 μM Fib-containing solution. The shift in the SPR angle was small for both cases. Obtained results suggested that the number of adsorbed Lyz was higher than that of adsorbed Fib.     

Crosslinking of PVC and NBR blends

The purpose of our work is to control the interfacial bonds between PVC and NBR using the ammonium salts of triazine thiols and dithiodimorpholine (DTDM) and thereby reveal the relation between the interfacial bonds and the final mechanical properties of products. In the experimental work a two-stage process was used. At first, an NBR/PVC blend was mixed with a mono-tetra-n-butylammonium salt of triazine trithiol at a temperature of 100°C on a two-roll mill to give the branching structure of triazine thiols into PVC. In the second stage branched NBR/PVC reacted with DTDM to afford the branched PVC containing trithiomorphonyl groups. In the presence of ZnO at 160°C trithiomorphonyl groups react with NBR to form a crosslinking structure between NBR and PVC. The mechanical properties of cured NBR/PVC blends were markedly improved by the treatment process and after addition of tetramethylthiuram monosulphide also. The mechanical properties were not improved by increasing the concentration of TT-TBA (tetrabutylammonium salt of 1,3,5-triazine-2,4,6-trithiol) over 4.2 phr.     

A Fail-safe Logic Operator Using an Insulated Planar Transformer

A fail-safe logic circuit must switch the output signal to the logical value “0” when an operation circuit fails. A transformer has such favorable characteristics for fail-safe logic circuits as only the magnetic flux change is transmitted and a superposition of magnetic flux is realized. Thus those characteristics arc applied to a failsafe logic operator. A new fail-safe logic operator using an insulated planar transformer was developed for a fail-safe majority operation and a fail-safe interlocking. In this paper, the principle, structure, design and fundamental characteristics of the new fail-safe logic operator are described.     

Preparation of plasma-polymerized membranes from fluoroalkyl acrylates and methacrylates and gas permeability through the membranes

Summary Plasma-polymerized membranes were prepared from fluoroalkyl acrylates and methacrylates by two different directions of monomer injection and the permeation rates of O₂ and n₂ through the membranes were investigated. The chemical structure and composition of the plasmapolymerized membranes varied significantly by the direction of monomer injection. The optimum plasma conditions to yield maximum gas separation characteristics was obtained by the remote plasma excitation at the W/FM value of 20 J/mg, where W is the discharge power, F is the monomer flow rate and M is the molecular weight of the monomer.     

Influence of physical relaxation on chemical stress–relaxation of natural rubber vulcanizates

Networks were prepared in the swollen and dry states to investigate the influence of physical relaxation on chemical stress–relaxation. The stress–relaxation behavior of solution-cured samples was different significantly from that of the samples crosslinked conventionally. The same result was also observed in the number of chain scission for both kinds of samples. On the other hand, the number of chain scission estimated by using the swelling method for samples crosslinked conventionally was in good agreement with that by the chemical stress–relaxation for solution-cured samples. It was found that there is little or no influence of the physical relaxation caused by entanglements, and no effect of dangling chains arising from scission in the equilibrium swelling. The relative change of network chain density determined by means of the swelling method was also consistent with that by sol fraction determination. These results indicate that the swelling method can be used as a measure of a degree of degradation on chemorheology. Taking into account the influence of physical relaxation on chemical stress–relaxation, a new relationship between the relative stress decay and the relative network chain density was experimentally proposed.     

Behaviour of the spin-spin relaxation time for natural rubber vulcanizates under large deformation

The spin-spin relaxation time, T₂, for DCP-cured natural rubber with various crosslink densities, v_e, has been measured under various deformation. T₂ is separated into two components: one is the long T₂ component, T_2L, for the mobility of amorphous network chains, the other is the short one, T_2S, for that of the strain-induced crystalline chains. T_2L decreased exponentially with increasing extension ratio,α, and the decreasing rate was more remarkable with increasing v_e. The α and v_e dependence of T_2L has been quantitatively explained by the equation experimentally derived by Nishi et al.T_2L under various extension increased and became almost constant with increasing temperature, while the corrected fraction of T_2S, T_2S (%), gradually decreased. The apparent melting point, T_m, at which the corrected T_2S (%) was zero under various deformation was determined. The α dependence of T_m, has been discussed by using Flory's equation.