Shape memory gel

Among the adaptive materials currently on the forefront are liquid crystals, electro- and magneto-rheological (ER/MR) fluids, thermo- and physioreponsive gels, and shape memory alloys. In all but the last case, these systems involve... 

Also, PVA hydrogels evidenced a very good behaviour in contact with skin and other tissues, mucosa, or blood. PVA exhibits a bioadhesive nature, shape-memory properties, avoid the protein adsorption onto the gel surface and is biocompatible. 

Shape-memory materials are those materials that return to a specific shape after being exposed to specific temperatures. In other words, these materials are able to remember their initial shape. This process of changing the shape of the material can be repeated several times. The shape-memory effect has been observed in different materials, such as metallic alloys, ceramics, glasses, polymers and gels. 

Temperature-sensitive materials shape-memory materials Temperature-sensitive gels... 

Among various SPs, the materials that can sense signals and produce a definite dynamic response in the form of a change in shape or volume are under active investigation, such as shape-memory polymers (Lendlein et al, 2005), polymer gels (Liu and Calver, 2000 Zriny et al., 2000 Osada and Gong, 1998 Suzuki et al.,... 

When the gel content was low (e.g., 40% or less), the samples did not recover fully upon heating. On the other hand, when the gel content was high, the complete final recovery rate was obtained indicating the requirement of a network structure to achieve the property of shape memory effect. 

Osada, Y., and Matsuda, X. 1995. Shape-memory gel with order-disorder transition. Nature 376 219-223. 

Stimuli-responsive materials have sparked enormous interest in recent years due to their potential applications in micro-machines, soft robots, biomedical systems, etc. [1-6]. A variety of intelligent polymeric materials such as shape memory polymers [7, 8], polymer gels [9, 10], conducting polymers [11, 12], and dielectric elastomers [13,14] have been developed for these applications. Compared to other stimulus-driven methods including pressure [15], heat [16, 17], electric field... 

Gianoncelh, A., Brisotto, M., Bontempi, E., and Ricco, T. (2013) One-way and two-way shape memory behaviour of semi-crystalline networks based on sol-gel cross-linked poly(e-caprolactone). Polymer, 54 (16), 4253-4265. 

At present, important commercial cellulose esters inelude eellulose acetate butyrate, cellulose acetate propionate, and eellulose aeetate. In recent developments, a variety of cellulose chemicals, such as quatemized cellulose, carbo>ymethyl cellulose, methyl cellulose, 3-allyloxy-2-hydroxypropyl cellulose, and the hydroxyalkyl celluloses, have been synthesized via etherification reactions. In addition, cellulose derivatives have many applications, including antioxidant agents, shape memory gels, photoactive materials, gene carriers, and in memory devices. ... 

Fig. 2 Literature and patent analysis for the time period 1907-2008 according to pubUcadon date for the scientific publications and filing date for patents/patent applications. In all cases plural and singular forms of search terms were considered, (a) Result of literature search for shape-memory polymer in CAPlus database performed with Scifinder on March 12th, 2009 white - publications in English, gray - publications in Chinese or Japanese, black - other languages (b) result of two literature searches shape-memory gel, heat shrinkable polymer (all languages) performed in CAPlus database with Scifinder on March 12th, 2009 black - shape-memory gel, white - heat shrinkable polymer (c) result of patent search (issued patents and patent applications) for shape-memory polymer performed in DEPATIS database on Feb 27th, 2009 white - shape-memory polymer (d) result of patent search (issued patents and patent applications) for shape-memory gel, heat shrinkable article performed in DEPATIS database performed on Feb 27th, 2009 black - shape-memory gel, white - heat shrinkable article ...

Shape-Memory Gels with One Switching Domain... 

Hydrogels with hydrophobic, crystallizable side chains formed by copolymerization of acrylic acid and stearyl acrylate crosslinked with methylenebisacrylamide (BIS) showed a strong temperature dependence in their mechanical properties [91-93]. Such shape-memory gels having Tians = 7m displayed a reversible order-disorder transition associated with the interactions between the alkyl side chains. While behaving like hard plastic below 25 °C, softening above 50 °C enabled the materials... 

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