CAREER: Developing New Polymer Supported Catalysts with High School, Undergraduate, and Graduate Students

在这个由化学系(CHE)化学催化计划(CAT)资助的项目中，山姆休斯顿州立大学(SHSU)的克里斯托弗·霍布斯教授与本科生和研究生合作开发新型和可回收的化学催化剂。化学催化剂加快了化学反应的速度。催化剂通常用于制备塑料和药物等重要材料。人们希望制造寿命长的催化剂，以避免与经常使用的金属元素相关的高成本和环境问题。在这项研究中，聚合物载体(“塑料骨架”)被用来从反应中回收催化剂，以便它可以重复使用。根据聚合物载体的不同，开发了不同的分离策略。就像油和水分离的方式一样，霍布斯教授和他的学生开发的聚合物支撑催化剂是“相选择性的”，因此在促进化学反应后，它们在物理上与产物分离。这种绿色化学方法避免了浪费和耗时的净化步骤。该项目的教育方面旨在通过为实验室课程开发新的实验以及本科生参与研究实验室来扩大上海理工大学聚合物科学教育的范围。其他社会福利包括招募和参与温德姆学区未被充分代表的学生(高中生、本科生和研究生)的研究项目和志愿工作，担任数学和科学导师，为被关押在德克萨斯州刑事司法部(TDJC)的人提供公立学校系统。霍布斯教授和他的学生开发新的聚合物支撑的配体和催化剂，这些配体和催化剂是非极性和相选择性可溶的。这些聚合物负载的催化剂是通过开环歧化聚合(ROMP)、无环二烯歧化聚合(ADMET)和原子转移自由基聚合(ATRP)相结合的方式制备的。所有这些技术都提供了对聚合物体系结构的高水平控制。该项目的具体目标是聚合物支撑的Salen、N-杂环卡宾(NHC)和N-杂环的配体和催化剂。霍布斯教授正在进一步制备第一批相选择性单链纳米粒子(SCNP)和单分子配体/引发剂体系(ULIS)负载的催化剂。由于它们的非极性相选择性，这些催化剂可以在简单的液/液分离条件下回收和循环使用，从而避免了层析纯化。清除和回收的能力减少了溶剂浪费，并突出了该项目作为绿色和可持续化学的典范所产生的影响。这项工作的更广泛影响包括从代表不足的群体中招募学生进入STEM(科学、技术、工程和数学)职业，以及促进针对被关押在德克萨斯州刑事司法部(TDJC)系统的个人的外联和志愿服务。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In this project funded by the Chemical Catalysis Program (CAT) of the Division of Chemistry (CHE), Professor Christopher Hobbs of Sam Houston State University (SHSU) works with undergraduate and graduate students to develop new and recyclable chemical catalysts. Chemical catalysts increase the speed of chemical reactions. Catalysts are commonly used for preparing important materials such as plastics and medicines. It is desirable to make catalysts with long lives to avoid the high costs and environmental problems associated with the metallic elements that are often used. In this research, polymers supports ("plastic backbones") are used to recover a catalyst from a reaction so it can be re-used. Varied separation strategies are developed, depending on the polymer support. In much the same way that oil separates from water, the polymer-supported catalysts developed by Professor Hobbs and his students are "phase-selective" so they physically separate from the products after facilitating a chemical reaction. This green chemistry approach avoids wasteful and time-consuming purification steps. Educational aspects of this project are aimed at broadening the scope of polymer science education at SHSU through the development of new experiments for laboratory courses as well as hands-on participation in the research lab by undergraduates. Additional societal benefits include the recruitment and participation of under-represented students (high school, undergraduate, and graduate) in research projects and volunteer work as math and science tutors in the Windham School District, the public-school system for those incarcerated in the Texas Department of Criminal Justice (TDJC).Professor Hobbs and his students develop new polymer-supported ligands and catalysts which are nonpolar and phase-selectively soluble. These polymer-supported catalysts are prepared using a combination of ring opening metathesis polymerization (ROMP), acyclic diene metathesis (ADMET) polymerization, and atom transfer radical polymerization (ATRP). These are all techniques that offer high levels of control over polymer architecture. Specific goals of the project target polymer-supported salen, N-heterocyclic carbene (NHC), and N-heterocycle-based ligands and catalysts. Professor Hobbs is further preparing the first examples of phase-selective single chain nanoparticle (SCNP) and unimolecular ligand/initiator system (ULIS) supported catalysts. Because of their non-polar phase selectivity, these catalysts may be recovered and recycled under simple liquid/liquid separation conditions, thus avoiding chromatographic purifications. The ability to remove and recycle diminishes solvent waste and highlights the implications of this project as a model for green and sustainable chemistry. Broader impacts of this work include recruitment of students from under-represented groups to STEM (science, technology, engineering and mathematics) careers, as well as promoting outreach and volunteerism aimed at individuals who are incarcerated in the Texas Department of Criminal Justice (TDJC) System.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.