Biological fouling occurs everywhere in the marine environment and is a significant problem for marine vessels. Anti-fouling coatings have been used effectively to prevent fouling; however, these coatings harm non-targeted sea-life. Fouling-release coatings (FRC) appear to be an alternative way to combat fouling. FRC do not necessarily prevent the settlement of marine organisms but rather allow their easy removal with application of shear to the coatings surface. These coatings must be non-toxic, non-leaching, have low surface energy, low modulus, and durability to provide easy removal of marine organisms. Here the goal is to develop FRC based on thermosetting siloxane-polyurethane, amphiphilic polyurethane, and zwitterionic/amphiphilic polyurethane systems. A combinatorial high-throughput approach has been taken in order to explore the variables that may affect the performance of the final coatings. Libraries of acrylic polyols were synthesized using combinatorial high-throughput techniques by either batch or semi-batch processes. The design of the experiments for the batch and semi-batch processes were done combinatorially to explore a range of compositions and various reaction process variables that cannot be accomplished or are not suitable for single reaction experiments. Characterization of Rapid-GPC, high-throughput DSC, and gravimetrically calculated percent solids verified the effects of different reaction conditions on the MW, glass transition temperatures, and percent conversion of the different compositions of acrylic polyols. Coatings were characterized for their surface energy, pseudobarnacle pull-off adhesion, and were subjected to bioassays including marine bacteria, algae, and barnacles. From the performance properties results the acrylic polyol containing 20% hydroxyethyl acrylate and 80% butyl acrylate was selected for further siloxane-polyurethane formulations and were subjected to the same physical, mechanical, and performance testing. Amiphiphilic copolymers based on PDMS molecular weight and the addition of PEG based polymer blocks on the properties of acrylic-polyurethane coatings were explored. The key properties screened were surface energy, determined by contact angle measurements using water and methylene iodide, dynamic water contact angle, and pseudobarnacle adhesion properties. The data from all of the biological assays indicates that the novel coatings were able to resist fouling and have low fouling adhesion for the broad variety of fouling organisms tested.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22471号 / 工博第4732号 / 新制||工||1739(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 秋吉 一成, 教授 大内 誠, 准教授 松岡 秀樹 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Electric fields influence reactions by stabilization of charge-separated transition states. While this has been a longstanding hypothesis supported computationally, recent experimental confirmations highlight the potential for leveraging electric field effects to drive small molecule reactions far from equilibrium. Herein we report electric-field catalysis of an alkane solvent-derived acylation reaction in the scanning tunneling microscope-break junction (STM-BJ), providing additional support for this hypothesis. Additionally, the design and reactivity of an internally charged zwitterionic ligand are disclosed. Synthetic access of metal ligands bearing opposing charged functional groups permitted the examination of stochiometric metalation and catalytic behavior of electric field-bearing ligands.While traditionally computation has been used to rationalize why a particular catalyst is successful descriptively, it has been rarely used to screen candidates and prescriptively provide optimal catalyst structure. We report a neural network-enabled catalyst screening platform that dramatically reduce the resource intensity for examining a large chemical space. We leverage this platform to examine azolium N-heterocyclic carbene (NHC) precursors to address the lack of compatibility for electron-rich aryl aldehydes in the NHC-catalyzed Stetter reaction. This led to the discovery of a new class of azolium NHC precursor: oxadiazoliums that proved competent in achieving the target reaction addressing current limitations in Stetter catalysis.