Non-ionic polymer gel

Non-ionic polymer gel, swollen with dielectric solvent, can be extremely deformed as is the case for non-ionic polymer plasticised with non-ionic plasticiser. Instead of the charge-injected solvent drag as a mechanism of the gel actuation, the principle is based on local asymmetrical charge distribution at the surface of the gel18. The mechanism can also be applied to non-ionic elastomers in which the motion of the polymer chain is relatively free. In spite of their many difficulties for practical actuators, polyelectrolyte gels and related materials are the most interesting electroactive polymer materials. 

Hirai T., Zheng J., Watanabe M., Electrically active polymer materials - application of non-ionic polymer gel and elastomers for artificial muscles in Tao X. (ed.) Smart Fibres, Fabrics and Clothing, Woodhead Publishing, Cambridge. 2001. 

Electrically active polymer materials -application of non-ionic polymer gel and elastomers for artificial muscles... 

To overcome difficulties in polyelectrolytes, such as electrochemical consumption on the electrodes, we investigated the electroactive properties of the non-ionic polymer gel. 

Therefore, the authors tried to utilize non-ionic polymer gels as actuating materials with large deformation. The results show that the idea works in a far... 

Such a remarkable swift bending or crawling of a non-ionic polymer gel cannot be explained by osmotic pressure gradient, which is usually considered to be the reason for electrically induced bending in polyelectrolyte gel. As pointed out in the previous section, the solvent flow was suggested in the gel. We investigated the effect of an electric field on its flowing property. ... 

Non-ionic polymer gel swollen with dielectric solvent is shown to be extremely deformed, as is the non-ionic polymer plasticized with non-ionic plasticizer. 

As discnssed previously, HPMC is a non-ionic polymer and hence the polymer hydration and gel formation of its matrix is essentially independent of pH of a typical dissolntion media nsed. However, when drngs with pH-dependent aqneous... 

Wide span of large deforming non-ionic electro-active actuator materials from polymer gel, through plasticized polymer, to elastomer with no additives. A prosperous future for the conventional non-ionic polymer materials as autonomic materials can be expected. 

A new generation of mesoporous silica (SG) materials obtained by sol-gel technique where polymers and ionic or non-ionic surfactant act as stmcture - directed templates is widely developed during last year s. Final materials can be synthesized as thin films and used as sensitive elements of optical and electrochemical sensors. 

Sixteen solid-phase materials were tested on a laboratory scale and the antho-cyanin and sugar content of collected fractions were determined. Among these, reverse-phase silica gels and macroreticular non-ionic acrylic polymer adsorbents such as Serdolit PAD IV or Amberlite XAD-7 turned out to be most suitable. SPE was used to investigate these materials on an enlarged scale, improving elution gradient and column purification. Amberlite XAD-7 was successfully applied in a middle-scale separation. ... 

It is notable that the structure factors, proportional to the scattered intensity, for gels could be very different between gels composed of non-ionic neutral polymers and of ionized polymers. In the case of the non-ionic gels, the structure factor is characterized by the screening length of the polymer chains, which is the so-called correlation length, On the other hand, an additional screening... 

Kokufuta, Zhang and Tanaka developed a gel system that undergoes reversible swelling and collapsing changes in response to saccharides, sodium salt of dextran sulfate (DSS) and a-methyl-D-mannopyranoside (MP) [126]. The gel consists of a covalently cross-linked polymer network of W-isopropylacrylamide into which concanavalin A (ConA) is immobilized. As shown in Fig. 31, at a certain temperature the gel swells five times when DSS ions bind to ConA due to the excess ionic pressure created by DSS. The replacement of the DSS by non-ionic MP brings about collapse of the gel. The transition can be repeated with excellent reproducibility. 

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