Development of high functionality composites and nanocomposites for tissue engineering and energy conversion systems

在过去的十年中，功能性纳米复合材料将在各个领域发挥关键作用，包括可持续能源技术，如氢燃料电池，太阳能电池，组织工程等，它们可以提供相应的散装材料无法达到的性能。目前的重点放在控制其组成，形态，纳米结构和功能相对于其特定的应用。拟议的研究计划的目的是开发控制形态/功能纳米复合材料和生物相容性复合材料，特别是设计用于染料敏化太阳能电池（DSSC）光阳极，质子交换膜燃料电池（PEMFC）电极和双极板（BPP），以及用于软骨组织再生的生物相容性支架。 目前，软骨多孔支架，一旦开发，需要进一步的溶剂处理，以添加孔内的生物相容性材料，以促进细胞增殖，导致不需要的残留溶剂。我们建议首先 主题是无溶剂技术，以开发开放细胞支架，其中壳聚糖，一种生物相容性/生物降解性 天然聚合物，在支架发泡过程中被改性并直接投射在孔隙表面，由于壳聚糖改性而导致强粘附。 DSSC光阳极中二氧化钛（TiO 2）层的常规制造工艺需要高温烧结，导致脆性结构。那么，本提案第二个主题的目标-柔性结构的发展是一个挑战。基于我们在纳米结构TiO 2合成方面的专业知识，我们将使用室温静电纺丝技术从含有可控尺寸和形状的TiO 2-CdS纳米颗粒的聚合物基质中开发柔性纤维纳米结构。主要目的是通过提供大的光阳极表面积和增加与光敏染料的电子转移来增加光阳极柔性和电池效率。 作为本提案的第三个研究主题，我们将使用一个最近设计的实验装置与我们的战神流变仪兼容，以调查的“在线”演变的电导率行为在共同连续形态的纳米复合材料相对于他们的结晶动力学。这将有助于我们优化纳米复合材料的冷却曲线，以获得更高的电导率。我们还将进行一项原创性研究，研究动态剪切对熔融聚合物/聚合物系统电导率的影响。我们的目的是从这项研究中降低的阈值浓度的导电添加剂，从而提高纳米材料的可加工性和导电性，特别是需要基于聚合物的PEMFC电极和BPP。

During the last decade, functional nanocomposites are set to play a crucial role in various areas including sustainable energy technologies such as, hydrogen fuel cells, solar cells, tissue engineering, etc. They can offer performances that are not reachable by their corresponding bulk materials. The emphases are presently placed on the control of their composition, morphology, nanostructure and functionality with respect to their specific applications. The aim of the proposed research program is to develop controlled morphology/functionality nanocomposites and biocompatible composites particularly designed for dye-sensitized solar cell (DSSC) photoanodes, proton exchange membrane fuel cells (PEMFC) electrodes and bipolar plates (BPPs), and biocompatible scaffolds for cartilage tissue regeneration. Presently, cartilage porous scaffolds, once developed, need a further solvent treatment to add biocompatible materials inside the pores in order to promote cell proliferation, leading to unwanted residual solvents. We propose in this first theme a solvent-free technique to develop open cell scaffolds where chitosan, a biocompatible/biodegradable natural polymer, is modified and directly projected on the surface of the pores during scaffolds' foaming, leading to strong adhesion thanks to chitosan modification. The conventional manufacturing process of Titanium dioxide (TiO2) layer in DSSC photoanode requires a high temperature sintering, leading to a brittle structure. Then the development of flexible structures, object of the second theme in this proposal, is a challenge. Based on our expertise in the synthesis of nanostructured TiO2, we will use room temperature electrospinning technique to develop flexible fibrous nanostructures from a polymeric matrix containing TiO2-CdS nanoparticles of controlled size and shape. The main objective is to increase photoanode flexibility and cell efficiency by providing large photoanode surface area and increased electron transfer with the photosensitizing dye. As third research theme in this proposal, we will use a recently designed experimental setup compatible with our ARES rheometer in order to investigate the 'online' evolution of the electrical conductivity behavior in co-continuous morphology nanocomposites with respect to their crystallization kinetics. This will help us to optimize the cooling profile of the nanocomposites in order to attain higher electrical conductivity. We will also undergo an original study in which we will investigate the effect of dynamic shearing on the electrical conductivity of melted polymer/polymer systems. We aim from this study to decrease the threshold concentration of the conductive additives and consequently increase nanomaterials' processability and electrical conductivity, particularly needed for polymer-based PEMFC electrodes and BPPs.