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oai:www.ideals.illinois.edu:2142/105111 2023-07-11 col_2142_5131 com_2142_5130

Zimmerman, Steven C. Zimmerman, Steven C. Braun, Paul V. Cheng, Jianjun Sottos, Nancy R. Wang, Hsuan-Chin 2019-08-23T20:44:16Z 2019-08-23T20:44:16Z 2021-08-24T09:15:38Z 2017-10-23 2017-12 The strong research interest in encapsulation chemistry for functional chemical species (commonly referred to as active ingredients or actives) arises from the need to devise tailored strategies to protect precious actives from premature degradation or leakage. Furthermore, to maximize the performance of the encapsulated actives, a controllable method is needed to release the materials at the desired time, location, and rate. To address these challenges, scientists look to stimuli-responsive polymers as a solution because polymers can be designed with tailored properties thanks to advancement in polymer chemistry and engineering. This dissertation discloses a collaborative effort between the Zimmerman group and Dow Chemical to develop novel pH-responsive polymeric materials for encapsulation and triggered-release. As a release trigger, pH is attractive because of the prevalence of environments with specific pH levels. In the first part of the dissertation, a diester diacid chloride monomer, PDDC, was utilized in the preparation of a novel pH-responsive polyamide microcapsule. PDDC was selected for its susceptibility to hydrolysis as well as simplicity in structure and synthesis. A mixture of polyamine monomers, which includes a triazine trisamine crosslinker and the commercially available DETA, reacted with PDDC to afford toluene-loaded (ca. 95% by weight), free-flowing microcapsules through interfacial polymerization. Through dye release experiments, the triazine-DETA-PDDC microcapsules exhibited a unique pH-dependent release behavior: similarly fast, first order like release profiles at pH 5 and pH 10 and a steady, linear release profile at pH 7.4. In a dry or hydrophobic environment, the microcapsules remained stable without UV-Vis detectable dye release or rapid loss of the volatile core solvent. In summary, the PDDC polyamide chemistry utilizes a single set of synthetically scalable monomers to prepare multi-pH responsive microcapsules that could see applications in different pH environments. The second portion of the dissertation concerns a novel polyacetal that utilizes a new mechanism to facilitate degradation. A small molecule model compound containing the novel acetal moiety was synthesized and confirmed by NMR to show the expected degradation products under an acidic environment. Linear polymers bearing the novel acetal repeat unit were synthesized, with molecular weight up to 50 kDa as calibrated by PS standards. Crosslinked microcapsules bearing the novel acetal repeat unit were fabricated by interfacial polymerization. Encapsulation of a hydrophobic photoacid generator (PAG) in the core of the microcapsules demonstrated UV-triggered degradation. Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-12-01 The student, Hsuan-Chin Wang, accepted the attached license on 2017-10-19 at 02:45. The student, Hsuan-Chin Wang, submitted this Dissertation for approval on 2017-10-19 at 02:49. This Dissertation was approved for publication on 2017-10-23 at 15:57. DSpace SAF Submission Ingestion Package generated from Vireo submission #11690 on 2019-08-22 at 16:17:30 Made available in DSpace on 2019-08-23T20:44:16Z (GMT). No. of bitstreams: 3 WANG-DISSERTATION-2017.pdf: 3730408 bytes, checksum: b0954c90836ea31bc907a848dc50f613 (MD5) LICENSE.txt: 4212 bytes, checksum: 82c2098fcc0db0a98e4435e6b37aab8b (MD5) PROQUEST_LICENSE.txt: 4558 bytes, checksum: 821b86dfcf563a54f1be92537d331392 (MD5) Previous issue date: 2017-10-23 Embargo set by: Seth Robbins for item 112230 Lift date: 2021-08-23T20:44:50Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 112230 Lift date: 2021-08-23T20:46:41Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 112230 Lift date: 2021-08-23T20:47:38Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 112230 Lift date: 2021-08-23T20:48:32Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Limited Restriction Lifted for Item 112230 on 2021-08-24T09:15:38Z. application/pdf http://hdl.handle.net/2142/105111 en Copyright 2017 Hsuan-Chin Wang pH-responsive acid degradable microcapsules interfacial polymerization depolymerization PH-responsive polymeric materials for encapsulation and triggered release text text Chemistry Chemistry University of Illinois at Urbana-Champaign Dissertation Ph.D.