Stimulus type polymers

Another factor also contributed to the appearance of new concepts in electrochemistry in the second half of the twentieth century The development and broad apphca-tion of hthium batteries was a stimulus for numerous investigations of dilferent types of nonaqueous electrolytes (in particular, of sohd polymer electrolytes). These batteries also initiated investigations in the held of electrochemical intercalation processes. 

The reversible nature of DNA hybridization in response to an external stimulus causes this type of DNA-polymer hydrogels to have special properties, such as sol-gel phase transition and responsive releasing capability [93]. Thus, potential applications of these materials as label-free DNA sensing device or for controlled drug delivery have been discussed. Just a small portion of DNA is needed to achieve hydrogel responsiveness. 

The two types of nanotubes were joined by a polymer spacer, PAES-l -PS-l7-PAES. It was observed that the different blocks of these assemblies segregated from one another in block-selective solvents, such as DMF or toluene, and also in the solid state. This work represents yet another extension of hierarchical assembly of nano-objects by providing covalent bonds between nano-objects. Presumably, the bonds formed can also be reversible to a specific stimulus to find wider applications. 

The general problem of selecting the optimum NDT method for polymers and PMC requires consideration and balancing of several aspects. These are (f) requirements on type and size of indications that have to be detected with specified confidence compared to size and shape of the test object (2) technical feasibility of the test method, including behavior of the material imder the applied stimulus (3) availability of the test method (4) (eventually) formal requirements, eg, operator certification, test facility accreditation, test method validation (5) (eventually) compatibility with previous measurements and (6) overall cost. It would be of interest to have more quantitatively evaluated, comparative tests applying different NDT methods to specimens with simulated, known defects (80) or to real test objects. A comparative study of the cost of different NDT methods for polymer and PMC would also be welcome. 

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