19-02-2017, 05:15 PM
which mterial used in polymer memory ...explain briefly pls
19-02-2017, 05:15 PM
which mterial used in polymer memory ...explain briefly pls
20-02-2017, 11:01 AM
Abstract Form-memory polymers (SMPs) as stimulus-sensitive polymers are of great interest for fundamental research and technological innovation. In this contribution, a brief review of the recent trends in the field of SMPs is presented, with special emphasis on its structure, effects of memory of form and mechanism of work. Special attention is given to SMP intelligent and multi functional materials as emerging technological class. They are mainly described as shape memory nano composites (SMCs) where the incorporation of functional organic nanocargas (in) into the SMP matrices is done on purpose. Finally, potential applications of materials based on SMCs such as biomedical and medical devices, self-healing systems, self-expanding structures, actuators, sensors, etc. are outlined. Or its direct implementation in the industry. Introduction An emerging class of new materials are so-called "shape memory" compounds that include shape memory polymers (SMPs), alloys, hybrids, ceramics and gels. The main focus for the moment lies on SMPs due to a multitude of desirable qualities: low density, potentially recyclable at relatively low cost, high recoverable strain within a wide range of stimuli, transparency, chemical stability and modification, easier processing , Biocompatibility and biodegradability with the opportunity to adjust the rate of degradation. SMPs also prove to be modifying polymers in a way sensitive to programmable (multi) stimuli and have the remarkable property of recovering their initial form by direct heating or by Joule effect, radiation and laser heating, microwaves and pressure, humidity, solvent vapors Or solvent and change in pH values .. Depending on the degree of forms to acquire the materials may belong to multi-form or bidirectional SMPs. The first group relates to materials which are capable of memorizing more than one temporary form with subsequent retrieval in a highly controllable irreversible unidirectional manner. The second can be programmable and reversible switching between two different forms. The growing interest in the production of SMP is well highlighted by the increase in the number of publications over the last fifteen years dowlod pdf |
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