Heat Treatment By Rajan And Sharma Pdf Free 161
Artificial muscles made of cytoskeletal proteins, polysaccharides and conducting polymers can be actuated electrically, mechanically and even thermally . Over the past two decades, cytoskeletal proteins have been widely used in the development of biomimetic motility devices . For instance, Kojima et al. fabricated a microfluidic patterning device composed of an actin-based muscle that can be actuated through heat-induced contraction by raising the temperature above the transition Tm . Recently, Folguni et al. demonstrated a thermal actuator based on thermo-responsive polymer gelation that can reversibly move, oscillate and rotate . Mechanical soft materials are highly desired in micro-nanoelectromechanical systems (NEMSs) due to their large surface area and adaptive properties at the nanoscale . For instance, the specific surface area of an aerogel can be of the order of 102m2/m3, which is huge compared to metal nanoparticles . Increasing the porosity of a material generally decreases the heat capacity . This could be a promising feature in the case of nanocomposite materials with NPs embedded in a porous matrix (e.g., polymer aerogels ). However, in the case of the micro-masses, the decrease in heat capacity, which is the hallmark feature, is not always realized when NPs are incorporated in a host material. This is due to the increase in the relative amount of particles, which is accompanied by the reduction in grain boundary area, as shown in Fig. 5.1.
The selection of biomimetic crystallization methods depends on the materials employed and the purpose of the product [84, 85]. To achieve nano-immobilized lipase from Rhizomucor miehei (nano-immobilized lipase-RML) on chitosan fibers as biocatalysts, cell suspension was lysed by ultra-sonication, and the resulting lipase solution was added to the pre-gelatinized chitosan fibers under stirring. The crystallization process was monitored via microscopic images of the immersed chitosan-lipase fibers.