- BSc, (2015-2019): Synthesis and Characterization of Biodegradable Triboelectric Nano generator Based on Polycaprolactone /Sodium Alginate for Medical Applications
Energy and environmental crises in recent years have made moving towards clean and renewable energies a number of important issues. On a small scale, such as medical implants in the body, batteries are nowadays considered the most common equipment for power supply. Limited battery life, the need for access to replacements, large dimensions and high weight (compared to the entire system) and environmental damage caused by disposal are major problems for batteries. The invention of the nanogenerator can be considered the answer to these problems. NanoGenerators consist of micro or nano-sized structures that utilize the mechanical vibrations in the environment such as body muscle movement, fluid flow (such as blood), heat dissipation, and so on to supply the energy needed by different systems. These converters use two separate layers with completely different electrical properties, one of which has the ability to induce positive charge and the other to induce negative charge. Currently, the use of biodegradable nanosensors in various applications, especially medical applications, has been considered. The purpose of the present study is to develop and develop a biodegradable Triboelectric NanoGenerator for converting mechanical energy into electrical energy. In this study, polycaprolactone and alginate layers were used as positive and negative charge layers, respectively. To improve the triboelectric properties of the layers, correction processes were performed on each layer. In this case, the alginate layer was modified with graphene oxide with a negative surface charge to improve the anionic properties of this layer. In contrast, calcified rice bran was used to improve the triboelectric properties of the positive charge polycaprolactone layer. In this regard, while preparing polycaprolactone / calcined rice bran nanocomposite film, this material was also used for surface modification of nanocomposite film. Scanning electron microscopy and X-ray diffraction were used to characterize the layers. The surface roughness of the layers was evaluated using a roughness tester. Zeta potential test was used to evaluate the surface charge of rice bran before and after calcination and the morphology of bran beads was evaluated by scanning electron microscopy. The results show that the alginate / graphene oxide layer was successfully fabricated. The roughness results showed the uniform distribution of graphene nanoparticles in the alligeneate field confirming the interaction between the two components. The calcination process also resulted in an increase in the crystallinity of the rice bran with the basic silicate compound. The calcination process resulted in a decrease in the surface charge of the bran particles. Microscopic images also showed that deposition of rice bran particles on the surface of the polycaprolactone / bran layer resulted in the formation of mud morphology. Certainly, the presence of this highly specific surface layer structure can be appropriate to enhance the triboelectric properties of the substrate.