Controlled Porosity Materials: Before, During and After Sintering

可控孔隙率材料：烧结前、烧结过程中和烧结后

• 批准号: 9500282
• 负责人: Rosario Gerhardt
• 金额: $ 19.6万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-07-15 至 1999-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9500282&HistoricalAwards=false
• 关键词: Controlled; Porosity; Materials; Before; During

9500282 Gerhardt The objective of the proposed research is to determine the relationship between pore microstructure and thermal treatment for the creation of controlled porosity materials. To accomplish that task the following activities will be carried out: (1) Fabricate colloidal silica/soluble silicate monoliths having systematically varied microstructures with respect to both average pore size(s) and polydispersity. The pore structure will be engineered by modifications in chemical processing. (2) Characterize the microstructure of the precursor materials fully before sintering using a combination of microscopy (optical, and electron microscopy), and several different measurement techniques. (3) Quantitatively characterize the evolution of the microstructure ex-situ by means of pore size, shape and distribution measurements on isothermally sintered and quenched samples. Extend the sintering studies to in-situ isothermal sintering and simultaneous scattering experiments by means of a unique small angle neutron scattering furnace at the NIST reactor. (4) Utilize computer simulation and modeling to help elucidate the microstructural mechanisms responsible for the observed pore structure evolution. %%% Numerous engineering applications such as superinsulators, filters, and sensors require porous materials. Understand- ing the pore structure evolution during sintering is essential for the fabrication and control of the final microstructure in porous materials. Materials such as those studied in this project offer a notable opportunity, to tailor thermal conductivity for insulating purposes, dielectric constant for sensing devices and elastic modulus for porous structural ceramics.

9500282 Gerhardt提出的研究的目的是确定孔隙微观结构和热处理之间的关系，以创造可控孔隙率的材料。为了完成这项任务，将进行以下活动：(1)制造在平均孔径和多分散性方面具有系统变化的微观结构的胶体二氧化硅/可溶性硅酸盐单体。孔隙结构将通过化学处理中的修饰来设计。(2)结合显微镜（光学显微镜和电子显微镜）和几种不同的测量技术，在烧结前充分表征前驱体材料的微观结构。(3)通过对等温烧结和淬火试样的孔隙大小、形状和分布的测量，定量表征了非原位组织的演变。利用NIST反应堆独特的小角中子散射炉，将烧结研究扩展到原位等温烧结和同步散射实验。(4)利用计算机模拟和建模来帮助阐明孔隙结构演化的微观结构机制。许多工程应用，如超绝缘体，过滤器和传感器需要多孔材料。了解烧结过程中孔隙结构的演变对制备和控制多孔材料的最终微观结构至关重要。在这个项目中研究的材料提供了一个显著的机会，为绝缘目的定制热导率，为传感设备定制介电常数，为多孔结构陶瓷定制弹性模量。