RUI: Surface functionalization of photopolymerized organic-silica hybrid monoliths by photoinitiated grafting.

为了对当前分离科学和相关整料技术的进步做出重大贡献，所提出的研究的目的是制备和表征高效和保持性的光聚合有机-二氧化硅混合整料毛细管，每个毛细管具有光接枝聚合物涂层的纳米层。在这些类型的多孔整料材料中，整料的益处将与具有多种官能团的直接UV引发的表面改性相结合。这种新颖的方法允许简单和快速地制备具有不同化学性质的分离介质，这些化学性质是无法以其他方式实现的，因此为改进和创新的分离提供了机会。单块的独特双峰孔结构在低柱背压下的分离性能和选择性方面提供了增强的性能，从而能够进行快速和高通量的分析。目前可用的混合整料因其良好的机械稳定性和明确的多孔性质而闻名。在这项研究中，我们建议采用光接枝表面改性。这种技术代表了一种快速简单的紫外线引发方法，能够聚合，产生支化和交联结构。因此，聚合物纳米层的均匀分布允许高效屏蔽残留的硅烷醇基团，并因此增强混合整料的水解稳定性。此外，该方法受益于具有各种官能度的单体的商业可用性。因此，制备具有不同表面化学性质的高效且保持性的分离介质允许广泛的分离机制和多种选择的应用。将在UV透明熔融石英毛细管柱内制备整料。毛细管液相色谱法将用于毛细管的分离性能的评估，它将是一个直接测量的聚合物纳米层的表面覆盖。将通过一组关于保留、效率、渗透性和再现性、机械、热和pH范围稳定性的试验模型来评价制备的毛细管的性质。然后将这些新制备的毛细管与具有类似效率的柱的特性进行比较。各种技术，如扫描电子显微镜和氮气孔隙率测定法，将用于结构表征和测量的孔的物理化学性质。提出了一项研究，其中的物理化学特性和色谱性能的一系列整料，每个与光接枝的纳米层的各种聚合物涂层之一。更具体地，将制造具有各种光接枝氟化官能团的光聚合有机-二氧化硅混合整料，并且将确定它们对广泛极性的分析物的反相分离的适用性，以及密切相关的卤化化合物。该设计为开发快速、简单和有效的化学修饰奠定了基础。表面化学的选择允许制备用于反相、阴离子或阳离子交换、手性识别或更精细形式的色谱的分离介质。在更广泛的范围内，该模型保证了选择各种具有不同官能团的有机单体，用于制备具有不同表面化学的整体固定相，以在广泛的分离机制中发挥作用。诸如色谱分离、多相催化和固相萃取等依赖于与固体表面相互作用的应用将极大地受益于多功能的引入。该项目代表了与加州伯克利劳伦斯伯克利国家实验室（LBNL）分子铸造用户设施的有机和大分子设施现有合作的延续。该项目将主要在巴里大学和LBNL部分执行。巴里大学是一所联邦指定的西班牙裔服务和少数民族服务高等教育机构，学生中有67%是女性。本科科学专业的学生将在PI的直接指导下获得实践经验。参与研究将扩大他们的教育，并将大大有助于他们的科学成长。研究结果将通过在科学会议上的介绍以及在与拟议专题有关的科学期刊上发表的形式传播

1066113ZajickovaIn an effort to contribute significantly to the progress of current separation science and related monolith technology, the objectives of the proposed studies are to prepare and to characterize highly efficient and retentive photopolymerized organic-silica hybrid monolithic capillaries each having a nanolayer of photografted polymer coating. In these types of porous monolithic materials the benefits of monoliths will be combined with straightforward UV-initiated surface modification with a wide variety of functional groups. This novel approach allows for simple and fast preparation of separation media with diverse chemistries that are not otherwise achievable and therefore provides opportunities for improved and innovative separations. The unique bimodal pore structure of monoliths provides enhanced properties in terms of separation performance and selectivity at low column back pressure thus enabling fast and high throughput analyses. Currently available hybrid monoliths are known for their good mechanical stability and well-defined porous properties. In this study we propose to employ photografting for surface modification. This technique represents a fast and simple UV-initiated approach that enables polymerization, creating branched and crosslinked architecture. As a result, the homogeneous distribution of the polymer nanolayer permits highly efficient shielding of the residual silanol groups and therefore enhanced hydrolytic stability of the hybrid monolith. In addition, this process benefits from the commercial availability of monomers with various functionalities. As a consequence preparation of highly efficient and retentive separation media with diverse surface chemistry permits a wide range of separation mechanisms and selection variety of applications. Monoliths will be prepared inside UV-transparent fused silica capillary columns. Capillary liquid chromatography will be utilized for the assessment of the separation performance of capillaries and it will be a direct measure of the surface coverage with the polymer nanolayer. The properties of the prepared capillaries will be evaluated by means of a model set of tests with respect to retention, efficiency, permeability, and reproducibility, mechanical, thermal and pH-range stability. These newly prepared capillaries will then be compared to the characteristics of columns of similar efficiency. Various techniques, such as scanning electron microscopy and nitrogen porosimetry, will be used for the structural characterization and the measurement of the physico-chemical properties of the pores. A study in which the physico-chemical characteristics and the chromatographic performance of a series of monoliths each with a photografted nanolayer of one of a variety of polymer coatings is proposed. More specifically, photopolymerized organic-silica hybrid monoliths with various photografted fluorinated functionalities will be fabricated and and their suitability for reversed-phase separation of analytes of wide range of polarities, and closely related, and halogenated compounds will be determined. This design establishes a foundation for the development of fast, simple and efficient chemical modifications. Selection of surface chemistry permits the preparation of separation media for reversed-phase, anion- or cation-exchange, chiral recognition, or more refined forms of chromatography. In a broader scope, this proposed model warrants selection of a variety of organic monomers with different functional groups for the preparation of monolithic stationary phases with diverse surface chemistries to function in a wide range of separation mechanisms. Applications such as chromatographic separations, heterogeneous catalysis, and solid phase extraction that rely on interactions with a solid surface will greatly benefit from the introduction of multiple functionalities. This project represents the continuation of an existing collaboration with the Organic and Macromolecular Facility at the Molecular Foundry User Facility at the Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA. This project will be mainly executed at Barry University and partially at LBNL. Barry University is a federally designated Hispanic-Serving and Minority-Serving Institution of higher education with a student body that is 67% female. Undergraduate science majors will gain hands on experience under the direct mentorship of the PI. Involvement in research will broaden their education and will significantly contribute to their scientific growth. The results will be disseminated through the presentations at scientific conferences and in the form of publications in scientific journals related to the proposed topic