Homogeneous copolymers films

Perhaps more important than cost is the solution to the crucial problem of interfacial contacts that always plagues homogeneous GPE films prepared from traditional approaches. Since both cathode and anode composite materials are coated on their substrates with the same PVdF—HEP copolymer as the binder, the in situ gellification following the electrolyte activation effectively fuses the three cell components into an integrated multilayer wafer without physical boundaries, so that the interfaces between anode and electrolyte or cathode and electrolyte are well extended into the porous structures of these electrodes, with close similarity to the interfaces that a liquid electrolyte would access. 

Mixtures of chemically homogeneous copolymers yield homogeneous films at Apmma below 25. 

The QCM-D response to mass uptake on the crystal oscillator is reflected in the changes in both the resonant frequency (Afi and dissipation factor (AD) at different overtones. In contrast to OWLS, the QCM-D approach is sensitive to viscoelastic properties and the density of any mass coupled to the mechanical oscillation of the quartz crystal. In this case, the adsorbed mass consists of the PLL- -PEG copolymer along with solvent molecules associated with it. A Voigt-based model was therefore used in the analysis (software Q-tools, version 2.0.1), where the adsorbed layer was represented as a homogeneous, viscoelastic film characterized by shear viscosity ((/shear), shear modulus (Eshear), and film thickness (htum) (20—22). 

The freeze-dried complexes and PEO-b-PLA copolymer were dissolved in chloroform to a concentration of 0.1 g/ml. The solution was vortexed and sonicated to ensure total dispersion and homogeneity. Then it was poured onto glass microslide and left to dry under room cmiditions for 2 days to cast copolymer films with approximately 0.1 mm thickness. The resulting dried film was immersed in an aqueous solution at a pH > 8 to initiate the disassembly of the polymeric micelles and promote their elimination. The films were later placed under vacuum for 24 h to ensure total evaporation of the solvent. However, the study of the films structure and morphology is still in a preliminary stage and thus no results will be shown in this study regarding the films. 

Another important result was the finding that inhomogeneous binary mixtures of chemically uniform copolymers did not homogenize upon adding a third copolymer capable of forming clear films with each of the two mixture components. As Molau (4) already found in the styrene-acrylonitrile system there is no homogenization. ... 

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