Understanding Mesoscale Structures of Nanocrystalline Domains in Silk using Sum Frequency Generation Vibrational Spectroscopy

使用和频产生振动光谱法了解丝绸中纳米晶域的介观结构

• 批准号: 2203635
• 负责人: Seong Kim
• 金额: $ 36万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2203635&HistoricalAwards=false
• 关键词: Understanding; Mesoscale; Structures; Nanocrystalline; Domains

With support from the Chemical Measurement and Imaging (CMI) program in the Division of Chemistry (CHE), and co-funding from the Biomaterials Program (BMAT) in the Division of Materials Research (DMR), Dr. Seong Kim and his team at Penn State University are developing powerful probes of the way living organisms assemble water-soluble materials to produce insoluble semi-crystalline polymers to serve various mechanical functions such as structural support and energy storage. Their work aims to advance current understanding of how structural order is exploited by living organisms to tailor mechanical properties of crystalline biopolymers like those found in silk fibers. The approach will utilize sophisticated spectroscopic tools to quantitatively probe structural order and assembly inside natural silk. Students from underrepresented groups, including first-generation college students, will be involved in these modern spectroscopic studies, working in close collaboration with Dr. Kim and his graduate students. The research motivations and methodologies will be integrated into a graduate-level materials characterization course. Outreach activities associated with the Frost Entomological Museum at Penn State will help familiarize the general public with the science of materials produced by arthropods The main characterization method of this work is vibrational sum-frequency-generation (SFG) spectroscopy - a nonlinear optical process originating from noncentrosymmetry. While SFG is typically considered to be a surface-sensitive tool, it can also distinguish noncentrosymmetric arrangements of molecules from their disordered surroundings. While potentially useful as a probe of nano- to meso-scale order of noncentrosymmetric crystals dispersed in an amorphous polymer matrix (e.g., beta-sheet domains in silk fibers), the challenges encountered in the analysis of multi-scale three-dimensional structures are far beyond the complexity of two-dimensional surfaces. To address this obstacle, the Kim group is working to: (i) establish the SFG spectral interpretation of beta-sheet moieties prevalent in natural silk fibers; (ii) decipher mesoscale three-dimensional order of crystalline beta-sheets in silk; and (iii) conduct operando SFG analysis of silk fibers under stress-free and tensile strain states in controlled humidity conditions. The operando SFG methodology and knowledge established from this study will likely be applicable to studies of other natural biopolymers such as chitin, collagen and elastin as well as biomimetic materials, highlighting the potential for broad scientific impact of this work.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学测量和成像（CMI）方案（CHE）（CHE）的支持下，并从生物材料计划（BMAT）共同​​基金会在材料研究部（DMR）（DMR）中，宾夕法尼亚州立大学博士和他的团队在宾夕法尼亚州立大学的团队中，正在开发出强大的材料的强大探针，以使水材料构成材料的各种机制，这些机制能够像材料一样，以供水材料来供应，以供材料供应，以供材料供应材料。和储能。他们的工作旨在促进当前对生物生物体如何利用结构秩序的理解，以量身定制晶体生物聚合物的机械性能，例如在丝纤维中发现的生物聚合物。该方法将利用复杂的光谱工具来定量探测结构秩序和天然丝中的组装。来自代表性不足的团体的学生，包括第一代大学生，将与Kim博士及其研究生密切合作，参与这些现代光谱研究。研究动机和方法将纳入研究生级的材料表征课程。 与宾夕法尼亚州霜冻博物馆相关的外展活动将有助于使公众熟悉该作品的Arthropods产生的材料科学。这项工作的主要特征方法是振动总和 - 频率生成（SFG）光谱 - 一种非线性光学过程，起源于非质子对象。 尽管通常认为SFG是表面敏感的工具，但它还可以将分子的非中心对称排列与其无序环境区分开。虽然有可能可作为探测纳米尺度的探针，但分散在无定形聚合物矩阵中的非中心对称晶体（例如，丝绸纤维中的β-片域域）中，虽然有用，但在分析多尺度的三维结构的分析中，遇到的挑战远远超出了两维型的复杂性。为了解决这一障碍，KIM集团正在努力：（i）建立对天然丝纤维中β-材料部分的SFG光谱解释； （ii）丝绸中的晶体beta表格中尺度三维序列； （iii）在受控的湿度条件下，在无压力和拉伸应变状态下，对丝纤维进行操作SFG分析。根据这项研究确定的Operando SFG方法和知识可能适用于其他天然生物聚合物（例如几壳，胶原蛋白和弹性蛋白）以及仿生材料的研究，突出了该工作对广泛的科学影响的潜力。该奖项反映了NSF的法定任务，并通过评估该基金会的智力效果，并通过评估了基金会的范围和广泛的范围。