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Full-Text Articles in Chemistry

Protein Detection And Structural Characterization By Mass Spectrometry Using Supramolecular Assemblies And Small Molecules, Bo Zhao Oct 2019

Protein Detection And Structural Characterization By Mass Spectrometry Using Supramolecular Assemblies And Small Molecules, Bo Zhao

Doctoral Dissertations

Mass spectrometry (MS) has played an increasingly prominent role in proteomics and structure biology because it shows superior capabilities in identification, quantification and structural characterization of proteins. To realize its full potential in protein analysis, significant progress has been made in developing innovative techniques and reagents that can couple to MS detection. This dissertation demonstrates the use of polymeric supramolecular assemblies for enhanced protein detection in complex biological mixtures by MS. An amphiphilic random co-polymer scaffold is developed to form functional supramolecular assemblies for protein/ peptide enrichment. The influences of charge density and functional group pKa on host-guest interactions …


Providing Molecular Insight For Understanding Anion Exchange Membrane Conductivity, Michael Kwasny Oct 2019

Providing Molecular Insight For Understanding Anion Exchange Membrane Conductivity, Michael Kwasny

Doctoral Dissertations

Anion exchange membranes (AEMs) are notorious for having both low alkaline stability and poor ion conductivity in fuel cell operation conditions, with solutions to these two challenges often being developed independent of each other. The chemical instability of an AEM is viewed through degradation of the polymer backbone and the cationic species and improving a material’s stability is approached by altering the polymer backbone, the cation, or both. On the other hand, poor ion conductivity is typically addressed by modifying bulk membrane properties such as increasing the ion exchange capacity (IEC), changing the morphology, or increasing the water uptake. These …


Designing Ion-Containing Polymers With Controlled Structure And Dynamics, Joshua Enokida Oct 2019

Designing Ion-Containing Polymers With Controlled Structure And Dynamics, Joshua Enokida

Doctoral Dissertations

Ion-containing polymers are a unique class of materials for which strong electrostatic interactions dictate physical properties. By altering molecular parameters, such as the backbone chemical structure, the ion content, and the ion-pair identity, the structure and dynamics of these polymers can be altered. Further investigation of the molecular parameters that govern their structure-property relationships is critical for the future development of these polymeric materials. Particularly, the incorporation of ammonium-based counterions into these polymers offers a facile method to tune their electrostatic interactions and hydrophobicity. Applying this concept, a bulky dimethyloctylammonium (DMOA) counterion was used to modify the organic solubility of …


Double-Network Materials Via Frontal Polymerization & Supercritical Co2 Processing, Matthew Joseph Lampe Jul 2019

Double-Network Materials Via Frontal Polymerization & Supercritical Co2 Processing, Matthew Joseph Lampe

Doctoral Dissertations

This dissertation presents work focused on producing materials in non-equilibrium states by taking advantage of novel processing techniques. First, epoxy-based resins which can undergo radically promoted, cationic, thermal, frontal polymerization are investigated for their potential use as adhesives. These resins are found to be capable of sustaining propagating polymerization fronts between several different substrate materials, resulting in high levels of adhesion in some cases. In addition, a similar frontal resin was developed that can undergo sequential gelation and frontal polymerization. The gels are formed by radically crosslinking acrylate monomers within the epoxy resin. These gels can then be manipulated, and …


Reactive And Stimuli-Responsive Sulfonium-Based Polymer Zwitterions, Cristiam Santa Chalarca Jul 2019

Reactive And Stimuli-Responsive Sulfonium-Based Polymer Zwitterions, Cristiam Santa Chalarca

Doctoral Dissertations

This dissertation describes the synthesis and characterization of novel monomers and (co)polymer zwitterions that incorporate trialkylsulfonium cations. The novel materials presented herein constitute a unique type of polymer zwitterions that exhibit salt- and temperature-dependent water solubility as well as inherent reactivity. The behavior of these polymers in aqueous solutions, as nanostructures, and at liquid-liquid interfaces was studied; in all cases, the inherent reactivity of the polymers was harnessed towards the fabrication of novel polymers and soft materials. Following an introductory chapter, Chapter 2 describes the synthesis of sulfonium sulfonate monomers and polymer zwitterions. Both styrenic and methacrylic monomers were synthesized …


Design, Synthesis And Study Of Functional Amphiphilic Polymers And Their Applications, Huan He Jul 2019

Design, Synthesis And Study Of Functional Amphiphilic Polymers And Their Applications, Huan He

Doctoral Dissertations

Amphiphilic homopolymers with high densities of functional groups are synthetically challenging. Thiol-yne nucleophilic click reactions have been investigated to introduce multiple functional groups in polymers with high density. An electron deficient alkyne group bearing methacrylate monomer was polymerized using reversible addition−fragmentation chain-transfer (RAFT) polymerization. Subsequently, the electron deficient alkyne group on polymer side chain was readily reacted with a thiol reagent using triethylamine (TEA) as the organocatalyst. This reaction was found to be very efficient under mild conditions. The resultant homopolymer bearing thiol vinyl ether functional groups could perform a second thiol addition with a stronger base, such as triazabicyclodecene(TBD), …


Modification Of 2d Materials Utilizing Functional Polymer Interfacial Layers, Ryan Selhorst Jul 2019

Modification Of 2d Materials Utilizing Functional Polymer Interfacial Layers, Ryan Selhorst

Doctoral Dissertations

This dissertation describes the modification of 2D transition metal dichalcogenides (TMDCs). These materials exhibit unique electronic properties, ranging from metallic to insulating, and can transport either electrons (n-type) or holes (p-type). Polymers containing electronically-active moieties offer a path to control the electronic properties of a 2D material without altering the inherent structure of the semiconductor. This dissertation focuses on the synthesis of polymers bearing chalcogen-rich or zwitterionic moieties to alter the electronic and solution properties of 2D materials. Chapter 2 describes polymers containing sulfur-rich tetrathiafulvalene (TTF) and their effects as electroactive coatings on the TMDC molybdenum disulfide (MoS2). …


Bio-Inspired Polymers That Bind And Deliver Protein Cargo, Nicholas D. Posey Mar 2019

Bio-Inspired Polymers That Bind And Deliver Protein Cargo, Nicholas D. Posey

Doctoral Dissertations

Delivering functional proteins and antibodies into cells can allow researchers to probe the intracellular environment, discover new cellular pathways, and pioneer new therapeutics. However, the entry of exogenous, charged molecules, like proteins, into the cell is usually restricted by the membrane, thereby hindering intracellular delivery. Membrane permeable molecules such as cell penetrating peptides (CPPs) and protein transduction domains (PTDs) can be used to bypass the cell membrane and deliver protein into the cell, but these peptides involve iterative and laborious syntheses and are limited in terms of their chemical diversity. This dissertation work overall focuses on the design and synthesis …


Enhanced Mass Spectrometric Analysis Of Peptides And Proteins Using Polymeric Reverse Micelles, Mahalia Adelina Corazon Paningbatan Serrano Mar 2019

Enhanced Mass Spectrometric Analysis Of Peptides And Proteins Using Polymeric Reverse Micelles, Mahalia Adelina Corazon Paningbatan Serrano

Doctoral Dissertations

Mass spectrometry (MS) has become a key and indispensable tool in the identification, characterization, and quantitative analysis of proteins owing to its universality, sensitivity, specificity, and its capability for multiplexed detection. Because biological samples containing these protein analytes are almost always complex systems, various techniques are employed in conjunction with MS to fully harness its analytical potential and enhance its detection capabilities. This dissertation explores the use of amphiphilic polymeric reverse micelles in enriching proteins and peptides from complex biological mixtures and in enhancing their mass spectrometric analysis. Fundamental studies that elucidate the molecular basis for the observed MS signal …


Design And Self-Assembly Of Responsive Scaffolds For Food And Sensing Applications, Uma Sridhar Mar 2019

Design And Self-Assembly Of Responsive Scaffolds For Food And Sensing Applications, Uma Sridhar

Doctoral Dissertations

Developing an understanding of how molecules, materials and complex systems contribute to biological functions is important since the interpretation of such mechanisms paves the way to further the development of materials that replicate natural functions or impart the observed properties to synthetic materials. The self-assembly of stimuli-responsive scaffolds based on micelles, liposomes, hydrogels and thin films has been of considerable interest. These systems need to be endowed with certain design features which influence the self-assembly and the responsiveness of the scaffold when subjected to external stimuli which could be physical, chemical or biological in nature. This kind of insight is …


Amphiphilic Assemblies With Responsive Characteristics At Surfaces And Interfaces, Piyachai Khomein Mar 2019

Amphiphilic Assemblies With Responsive Characteristics At Surfaces And Interfaces, Piyachai Khomein

Doctoral Dissertations

Amphiphilic self-assembly has gained a lot of interest in both academic and industrial fields. Amphiphiles have a unique ability to self-assemble in water, providing a range of nanosized materials of various morphologies. Many efforts have been dedicated to developing responsive amphiphilic assemblies by introducing responsive characteristics into the amphiphile building blocks. Responsive assemblies have been utilized in many promising applications such as targeted drug delivery systems, smart sensors, and electronic devices. Here, we reported four different types of responsive assemblies created via the incorporation of different responsive groups either at the material’s surface or interface. To achieve the responsive characteristics …