Self-assembling Polysaccharide Polyelectrolytes

自组装多糖聚电解质

• 批准号: 0724126
• 负责人: Alan Esker
• 金额: $ 42万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0724126&HistoricalAwards=false
• 关键词: Self; assembling; Polysaccharide; Polyelectrolytes

The Analytical and Surface Chemistry Program in the Division of Chemistry will support the collaborative research program of Prof. Alan Esker and Prof. Maren Roman of Virginia Tech University and Prof. Thomas Heinze of the University of Jena, Germany. This award coordinates with a collaborative award funded by the Deutsche Forschungsgemeinschaft (DFG) through a joint program between the NSF and DFG that jointly funds collaborative projects between US and German investigators. Wood represents a complex composite material comprised of three principle components: cellulose, hemicelluloses, and lignin. All three of these materials are polymers, large molecules made up of multiple units of similar chemical structure. Furthermore, cellulose and hemicelluloses are polysaccharides with sugar subunits, whereas lignin has a very different chemical structure. Even though cellulose and lignin prefer to form separate phases, like oil and water, wood has some material properties that are superior to composites of cellulose and manmade plastics. Hemicelluloses contribute to wood's superior properties by migrating to the interface between cellulose and lignin (self-assembly) and effectively "glue" them together during the formation of the tree's cell wall. The collaborative studies between the Esker and Roman groups and the Heinze group will focus on trying to mimic nature to create new biomaterials. The Heinze group will prepare new molecules that have properties of both hemicelluloses and lignin, while the Esker and Roman groups will prepare cellulose nanocrystals, cellulose fibers that are about ~20 nanometers thick (~1000 times thinner than a human hair) and several hundred nanometers long. These building blocks are polyelectrolytes, which contain multiple charges. Therefore, they will enable the researchers to use the principle that "opposites attract" to create complex structures in water from oppositely charged building blocks. Once the structures are formed, the researchers will use chemical reactions to lock the structures in place and study the mechanical and surface properties of the resulting composite materials. These composites should provide deep insight into the design of better membranes, sensors, medical materials, and additives for pulp and paper products. The project will provide excellent training opportunities to students in a highly multi-disciplinary area. It will will include international research experience for US students in Germany and for German students in the US.The award is co-funded by the Office of International Science and Engineering at NSF.

化学系的分析和表面化学项目将支持弗吉尼亚理工大学的Alan Esker教授和Maren Roman教授以及德国耶拿大学的托马斯海因策教授的合作研究项目。 该奖项与由德国研究共同体（DFG）通过NSF和DFG之间的联合计划资助的合作奖协调，该计划共同资助美国和德国研究人员之间的合作项目。木材代表由三种主要成分组成的复杂复合材料：纤维素、半纤维素和木质素。 这三种材料都是聚合物，是由化学结构相似的多个单元组成的大分子。 此外，纤维素和半纤维素是具有糖亚基的多糖，而木质素具有非常不同的化学结构。 尽管纤维素和木质素更喜欢形成单独的相，如油和水，但木材具有优于纤维素和人造塑料的复合材料的上级材料特性。 半纤维素通过迁移到纤维素和木质素之间的界面（自组装）并在树的细胞壁形成期间有效地将它们“粘合”在一起而有助于木材的上级性质。 Esker和Roman小组与Heinze小组之间的合作研究将集中在试图模仿自然创造新的生物材料。 Heinze小组将制备具有半纤维素和木质素性质的新分子，而Esker和Roman小组将制备纤维素纳米晶体，纤维素纤维约20纳米厚（比人类头发薄约1000倍），长数百纳米。 这些结构单元是聚电解质，含有多个电荷。 因此，它们将使研究人员能够利用“异性相吸”的原理，在水中从带相反电荷的积木中创造出复杂的结构。 一旦结构形成，研究人员将使用化学反应将结构锁定到位，并研究所得复合材料的机械和表面特性。 这些复合材料应该为设计更好的膜、传感器、医疗材料以及纸浆和纸制品添加剂提供深入的见解。 该项目将在一个高度多学科的领域为学生提供极好的培训机会。该奖项将包括为在德国的美国学生和在美国的德国学生提供的国际研究经验。