RUI: Supramolecular main-chain liquid crystalline networks as a probe of mesogen formation and stability

技术摘要：由固态和材料化学（SSMC）计划资助的初步研究表明，超分子液晶网络的创建产生了具有非常有趣性质的材料-简单的单环吡啶体系产生的网络将液态结晶度的降低与氢键受体的统计相关性联系起来。同样，更严格的群体允许更高浓度的干扰物包含。由简单的4-烷氧苯甲酸基形成的非大分子体系在干扰物负载超过99%时保持液态结晶度。SSMC的继续资助将允许开发具有不同功能的破坏氢键受体基团（双、三和四）的新系统，增加氢键受体组分（单环吡啶基或更长，二苯基结构）的刚性和尺寸。该研究将包括在所有氢键接受系统中引入灵活性：用于二键性的乙基糖氧基链，中间体形成受体（3、4和5）和烷基链（2、4、6和11个碳），用于增加柔性网络点的产生。这些系统将使用光谱学、热学和x射线分析技术进行研究。特别注意的是系统的组成，只是消除液体结晶度，因为这些将被用作中间相稳定性的探针。这些新液晶系统的创建将为中间相在不利的、受限的（网络化的）条件下稳定的能力提供有价值的见解，为中间相形成的本质提供见解，并比较涉及液晶形成的超分子力的数量和强度。这一研究成果将对超分子液晶领域产生广泛的影响。结合链结构的脆弱性限制了氢键介质的应用。赋予超分子液晶系统新的特性将提供新的材料，将共价体的稳定性与氢键结合链结构的稳定性和愈合能力结合起来。这项支持的工作将研究可逆键对液晶聚合物和网络的影响。这些材料将有助于理解非永久性连接对光学显示行业重要材料形成的影响。根据这项工作的结果，可以设计出新的可视化设备。除了该项目的科学影响外，活动还将用于加强研究基础设施，并为本科生提供进行潜在工业重要工作的机会。威斯康辛大学欧克莱尔分校超过一半的学生是低收入家庭（11%）或第一代学生（41%），其中约60%是女性，所有这些在科学界的代表性都不足。根据美国化学协会的数据，威斯康星大学欧克莱尔分校最近在化学专业毕业生数量上排名全国第三，是威斯康星州所有学院或大学中最高的。此外，几乎一半的UW- Eau Claire化学本科生进入研究生或专业课程。所描述的研究活动将极大地加强学生的训练和智力发展，通过对先进技术，设备的实践经验，并有机会发展他们的工作，以便在专业期刊上发表，并在国际会议上向该领域的专家展示他们的发现。

TECHNICAL SUMMARYInitial investigations funded by the Solid State and Materials Chemistry(SSMC) Program have indicated that the creation of supramolecular liquid crystalline networks produce materials with very interesting properties - simple one-ringed pyridyl systems produce networks that tie the reduction of liquid crystallinity in with statistical correlations of hydrogen bond acceptors. Similarly, more rigid groups allow for higher concentrations of disruptor inclusion. Non-macromolecular systems, created from simple 4-alkoxybenzoic acid groups retain liquid crystallinity at disruptor loadings above 99%. Continuation of funding from SSMC will allow for the development of new systems of varying functionality of the disrupting hydrogen bond acceptor groups (bis, tris and tetrakis), increasing rigidity and size of the hydrogen bond acceptor components (one ring pyridyl groups or longer, stilbazole structures). The study will include introduction of flexibility into all hydrogen bond accepting systems: ethyleneglycoxy chains for distonic, mesogen-forming acceptors (three, four and five) and alkyl chains (2, 4, 6 and 11 carbons) for increasing flexible netpoint creation. These systems will be studied using spectroscopic, thermal and x-ray analytical techniques. Special attention will be paid to the compositions of systems that only just eliminate liquid crystallinity, as these will be used as a probe for mesophase stability. The creation of these new liquid crystalline systems will provide valuable insight into the ability of a mesophase to stabilize in unfavorable, constrained (networked) conditions, providing insight into the nature of the formation of a mesophase, and a comparison of the quantity and strength of supramolecular forces involved in the formation of liquid crystals. The results from this work will have a broad impact on the field of supramolecular liquid crystals. The applications of hydrogen bonded mesogens are limited by the fragility of the associative chain structure. Imparting new characteristics to supramolecular liquid crystalline systems would provide new materials, combining the stabilities of covalent species with the lability and healing capabilities of hydrogen bonded associative chain structures. NON TECHNICAL SUMMARYThis supported work will study the effects of reversible bonding on liquid crystalline polymers and networks. These materials will aid in understanding the effects of non-permanent linkages on the formation of materials important to the optical display industry. New visualization devices could be designed from the results of this work. Beyond the scientific impact of this project, activities will be used to enhance research infrastructure and give undergraduate students opportunities to carry out potentially industrially significant work. Over half of the student body at the University of Wisconsin- Eau Claire is low-income (11%) or first generation (41%) and about 60% are female, all of which are underrepresented in the scientific communities. According to the American Chemical Society UW-Eau Claire was recently ranked third nationally in the number of chemistry graduates -the highest of any Wisconsin college or university. Also, almost half of all UW- Eau Claire Chemistry undergraduates matriculate into graduate or professional programs. The research activities described will greatly enhance student training and intellectual development through hands-on experience with sophisticated techniques, equipment and the opportunities to develop their work for publication in professional journals and to present their findings at international meetings to an audience of the experts in the field.