PMMA gels

Figure 4 Typical charge-discharge curve for Li/PMMA gel electrolyte/PPy battery. Charging and discharging current densities are 0.1 mA cnT2.

Figure 5 Dependence of coulombic efficiency ( ) and discharge capacity (O) of (a) Li/PMMA gel/PPy battery, (b) Li/PAN gel/PPy battery on number of cycles. Charging and discharging current densities are 0.1 mA cm-2.

Figure 6 Time dependence of Ri values which are estimated from the first semicircle (high frequency region) in the Cole-Cole plots of Li/PMMA gel/Li cell ( ) and Li/PAN gel/Li cell (O).

As mentioned above, a coin type Li polymer battery has high performance. In particular, the PMMA gel electrolyte is very stable toward lithium anodes. 

A secondary stereocomplex gel with the ratio [iso-PMMA]/[synd-PMMA] = 1/1 obtained from o-xylene solution showed an endothermic peak at 110 °C which was attributed to the melting point of the stereocomplex. The degree of crystallization was about 5-6%. Since this gel contained over 80% solvent, micro-Brownian motions of PMMA chains in the amorphous region were relatively unhindered. When the PMMA gel was cooled rapidly after melting above its Tm (i.e. above 145°C), first the loss modulus (c") changed relative to the viscosity of the system whereas the storage modulus began to increase after some time. This result confirms the assumption that first the polymer chains cannot be cross-linked but are weakly associated with one other, and then a... 

Network structure and its size inhomogeneity of poly(methyl methacrylate) (PMMA) gels through diffusional behaviour of probe PSs with different molecular weights... 

Figure 2 PFGStE hi NMR spectra of PMMA gel (PMMA gel sample 2) containing PS with...

PFGStE 1H NMR experiments for PMMA gel samples have been carried out at the diffusing time of A = 40 ms and then diffusional behaviour of PSs is observed in the PMMA gels. Figure 3 shows the plots of ln[A(y)/A(0)] against... 

Figure 3 Diffusional stimulated echo attenuations of PSs with different Mws in PMMA gels (PMMA gel samples 1-7) with CDCl3 as solvent, respectively, and PS in CDClj solution by varying field-gradient strength g. (O) PS in CDCl3 solution ( ) in PMMA gel prepared without PS (PMMA gel sample 1) (A) in PMMA gels prepared with PS (PMMA gel samples 2-7) The Mws of PSs are (A) 4000, (B) 19,000, (C) 29,000, (D) 50,000, (E) 170,000 and (F) 400,000.

Figure 4 Diffusional stimulated echo attenuation of PS (Mw = 4000) in PMMA gel sample 2 with CDCl3 as solvent by varying field-gradient strength g at room temperature, where A —40 ms (O), A = 60 ms ( ), A = 100 ms ( ), A = 300 ms ( ) and A = 500 ms (A).

TABLE 1 Determined diffusion coefficients of probe PS with Mw = 400,000 in PMMA gel sample 7 as a function of diffusing time A by PFGStE H NMR method... 

Diffusional behaviour of polystyrenes with different molecular weights in the same PMMA gel network... 

In Section 2.2,87 the network size inhomogeneity of PMMA gel was seen to be enhanced by increasing the PS Mw in other words, the most homogeneous network is obtained by PS-free cross-linking. In the case of the PMMA gel that is... 

TABLE 2 Diffusion coefficients of probe polystyrene (PS) molecules in the PMMA gel estimated by the PFGStE H NMR method... 

Figure 7 Mw dependence of diffusion coefficients of probe PSs (O) in deuterated chloroform solution, (A) fast diffusion component of PS in PMMA gel and ( ) slow diffusion component in PMMA gel.

Structural characterisation of inhomogeneous PMMA gels by time-dependent diffusion... 

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