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Öğe Block Copolymers by Mechanistic Transformation from PROAD to Iniferter Process(Wiley-V C H Verlag Gmbh, 2018) Çiftçi, Mustafa; Yagci, YusufA facile strategy for synthesizing block copolymers by the combination of two different living polymerization techniques, namely, photoinduced radical oxidation/addition/deactivation (PROAD) and iniferter processes is described. In the first step, PROAD polymerization of isobutyl vinyl ether using bromotriphenylmethane, dimanganese decacarbonyl (Mn-2(CO)(10)), and diphenyliodonium bromide (Ph2I+Br-) is carried out to yield polymers with triphenylmethyl (trityl) end groups. These prepolymers are used as macroiniferters in thermally induced free radical polymerization of vinyl monomers such as methyl methacrylate, tert-butyl acrylate, and styrene, resulting in the formation of corresponding block copolymers free from homopolymers. The precursor polymer and final block copolymers are characterized by H-1 NMR, FT-IR, GPC, and DSC analyses.Öğe Controlled Synthesis of Block Copolymers by Mechanistic Transformation from Atom Transfer Radical Polymerization to Iniferter Process(Wiley-V C H Verlag Gmbh, 2019) Aydogan, Cansu; Çiftçi, Mustafa; Yagci, YusufA straightforward transformation protocol combining two distinct living polymerization methods for the controlled synthesis of block copolymers is described. In the first step, bromo-terminated poly(methyl methacrylate) is prepared by atom transfer radical polymerization (ATRP). Then, a bromide end group is substituted with a triphenylmethyl (trityl) functionality under visible light irradiation using dimanganese decacarbonyl (Mn-2(CO)(10)) photochemistry. The resulting polymers with trityl end groups are used as macroiniferter for the polymerization of styrene and tert-butyl acrylate (tBA) to yield desired block copolymers with narrow molecular weight distribution. Moreover, the amphiphilic copolymers with acrylic acid functionalities are obtained by the hydrolyzation of poly(tert-butyl acrylate) containing block copolymers with trifluoroacetic acid.Öğe Controlled Synthesis of Hyperbranched Polymers by TEMPO-Mediated Radical Polymerization(Technical Assoc Photopolymers,Japan, 2020) Çiftçi, MustafaBranched polymers with tunable branching densities are prepared by TEMPO-mediated radical polymerization. Thus, styrene is copolymerized with 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO methacrylate) by using 2,2'-azobis(2-methylpropionitrile) (AIBN) as initiator at 125 degrees C. The method is based on the use of TEMPO methacrylate as branching unit that possessing a nitroxyl stable radical moiety as propagation radical trap and a polymerizable methacrylate group. Depending on the concentration of TEMPO methacrylate and polymerization time, hyperbranched polymers with different branching densities are obtained.Öğe Designing with Light: Advanced 2D, 3D, and 4D Materials(Wiley-V C H Verlag Gmbh, 2020) Jung, Kenward; Corrigan, Nathaniel; Çiftçi, Mustafa; Xu, Jiangtao; Seo, Soyoung E.; Hawker, Craig J.Recent achievements and future opportunities for the design of 2D, 3D, and 4D materials using photochemical reactions are summarized. Light is an attractive stimulus for material design due to its outstanding spatiotemporal control, and its ability to mediate rapid polymerization under moderate reaction temperatures. These features have been significantly enhanced by major advances in light generation/manipulation with light-emitting diodes and optical fiber technologies which now allows for a broad range of cost-effective fabrication protocols. This combination is driving the preparation of sophisticated 2D, 3D, and 4D materials at the nano-, micro-, and macrosize scales. Looking ahead, future challenges and opportunities that will significantly impact the field and help shape the future of light as a versatile and tunable design tool are highlighted.Öğe Hyperbranched Polymers by Light-Induced Self-Condensing Vinyl Polymerization(Wiley-V C H Verlag Gmbh, 2018) Aydogan, Cansu; Çiftçi, Mustafa; Yagci, YusufHyperbranched polymers (HBPs), a unique class of dendritic macromolecules, have received continuous interest from macromolecular scientists due to their inherent properties such as high level of functional terminal units, high solubility, and low viscosity. Despite enormous efforts devoted to the synthesis of HBPs by traditional methods such as single and double monomer strategies involving step-growth polymerization and self-condensing vinyl polymerization (SCVP) processes, there have been limited attempts to employ light-induced processes. Photochemical methods, however, exhibit distinct advantages not characteristically disclosed by traditional ones, such as spatial and temporal control, low energy, and site-specific activation. This review, after a brief summary of the conventional methods, presents the unique features and the key functionalities of the inimers for photoinduced SCVP and strategies for preparing HBPs.Öğe Mediating Reaction Orthogonality in Polymer and Materials Science(Wiley-V C H Verlag Gmbh, 2021) Corrigan, Nathaniel; Çiftçi, Mustafa; Jung, Kenward; Boyer, CyrilleSelective control of chemical reactions is critical for the proper regulation of processes ranging from intricate biological systems to large scale industrial manufacturing. The progression of synthetic chemistry toward the complexity seen in Nature requires increased control over many concurrent chemical reactions in a non-interfering (orthogonal) fashion. Fortunately, the practically endless pool of synthetic chemical reactions developed to date can often be combined in an orthogonal manner to provide elegant solutions to complex chemical problems. In this review, we first highlight some of the many photochemical reactions that have been applied in orthogonal reaction protocols; the highly selective nature of photochemical reactions makes them well-suited for independent activation in the presence of other reaction components. The application of these orthogonal reactions, especially photochemical reactions, for the synthesis and modification of polymers and polymeric materials is also summarized. Importantly, the use of orthogonal chemical reactions can provide additional opportunities for synthesizing advanced and functional polymeric materials compared to traditional synthetic procedures.Öğe Photoinduced Synthesis of Block Copolymers by Combining Atom Transfer Radical Polymerization and Photoinduced Radical Oxidation/Addition/Deactivation(2018) Çiftçi, MustafaA new polymerization mechanistic transformation strategy, combining two different techniques of controlled polymerization modes, namely atom transfer radical polymerization (ATRP) and photoinduced radical oxidation/addition/deactivation (PROAD), is effectively used for the block copolymers’ formation. Thus, mono- or bi- bromide functional polystyrenes (PS-Br or Br-PS-Br) synthesized by light-induced ATRP were used as a macroinitiator on isobutyl vinyl ether in the living cationic polymerization via PROAD process to give the corresponding block copolymers. Thus, depending upon the macroinitiator’s surface, AB/ABA type block copolymers (PS-b-PIBVE or PIBVEb- PS-b-PIBVE) were formed. The final polymers and precursor polymers were characterized by spectral and chromatographic analyses.Öğe Polydiacetylene for the Detection of alpha-Hemolysin in Milk toward the Diagnosis of Bovine Mastitis(Amer Chemical Soc, 2020) Weston, Max; Çiftçi, Mustafa; Kuchel, Rhiannon P.; Boyer, Cyrille; Chandrawati, RonaEarly diagnosis of mastitis is essential to reduce the expenses it imparts on the dairy industry. Existing techniques fail to provide rapid and pathogen-specific information to direct the prescription of antibiotics. Polydiacetylene (PDA)-based colorimetric sensors have emerged as promising bacterial screening tools that show potential for application in the diagnosis of bacterial infections. However, there are challenges in operating PDA sensors in complex samples, as identified in our recent work. To overcome this challenge, herein, we design and synthesize a custom diacetylene monomer via a copper-catalyzed cross-coupling reaction to yield 6,8-tricosadiynoic acid. Photopolymerization of 6,8-tricosadiynoic acid monomers yields blue-phase PDA with superior chromatic stability to milk constituents and reduced chromatic response to temperature fluctuations, which diminish the likelihood of false positives. We then form functionalized PDA vesicles by insertion of 1,2-dimyristoyl-sn-glycero-3-phosphocholine phospholipid and cholesterol in the PDA membrane. This allows the detection of alpha-hemolysin, a hemolytic toxin excreted by Staphylococcus aureus, a predominant causative pathogen of bovine mastitis. We demonstrate the detection of alpha-hemolysin in phosphate-buffered saline (limit of detection (LOD) = 3.62 mu g/mL) and milk samples (LOD = 6.62 mu g/mL) by a blue to red color change visible to the naked eye. The color change is studied by absorption spectroscopy and digital colorimetric analysis of photographs. We attribute the color change to pore formation in the PDA membrane and lysis of the vesicles due to the action of the S. aureus alpha-hemolysin. This is evidenced by vesicle membrane destruction in transmission electron microscopy micrographs of PDA vesicles before and after incubation with the toxin. The specificity of the sensor is demonstrated by discrimination between alpha-hemolysin and other toxins and biomarkers for mastitis. This is the first custom-designed PDA for point-of-care application in bovine milk samples and the first documented detection of alpha-hemolysin using a PDA-based sensor.Öğe Synthesis of graft copolymers by combination of radical photopolymerization and iniferter process(Wiley, 2019) Çiftçi, MustafaVarious PS-based graft copolymers including polystyrene-graft-poly(methyl methacrylate) and poly(styrene-graft-poly(ethylene glycol) methacrylate) are prepared via subsequent visible light radical photopolymerization and iniferter processes. Thus, poly(styrene-co-4-chloromethylstyrene) P(S-co-VBC) is synthesized by light induced free-radical polymerization. Then, chloride moieties are substituted with triphenylmethyl (trityl) groups to give trityl-substituted PS (PS-trityl) under visible light irradiation using dimanganese decacarbonyl (Mn-2(CO)(10)) photochemistry. Side chains are then grafted from PS-trityl backbone via iniferter process to give desired graft copolymers in a controlled manner. The precursor intermediates and the final graft copolymers are analyzed by H-1 NMR, FT-IR, and GPC measurements. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1344-1348Öğe Synthesis of Polysulfone Based Amphiphilic Graft Copolymers by a ‘Grafting to’ Approach(2019) Çiftçi, MustafaSynthesis of amphiphilic polysulfone graft copolymers by ‘‘Click’’ chemistry is described. First, a commercial PSU was chloromethylated to give chloro-funtional PSU (PSU-Cl). Subsequently, chloride groups were converted into azide moieties by nucleophilic substitution. Hydrophilic poly(N,Ndimethylacrylamide) (PDMA) side chains were then attached via a “grafting to” approach by using coppercatalyzed azide–alkyne cycloaddition (CuAAC). Precursor polymer and the final amphiphilic copolymers were characterized by proton nuclear magnetic resonance ( 1H NMR), fourier-transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC) and contact angle measurements.Öğe Visible light induced one-pot synthesis of amphiphilic hyperbranched copolymers(Elsevier Sci Ltd, 2018) Aydogan, Cansu; Çiftçi, Mustafa; Asiri, Abdullah Mohamed; Yagci, YusufDimanganese decacarbonyl (Mn-2(CO)(10)) and alkyl halide combination has unique visible light radical generating property which is useful in the fabrication of many complex macromolecular structures. Herein, we present a generic simple and rapid synthetic approach for the preparation amphiphilic hyperbranched macromolecular structures with controlled branching density and hydrophilicity. The method is based on the visible light induced self-condensing vinyl copolymerization of methyl methacrylate (MMA), 2-(2-bromoisobutryloxy) ethyl methacrylate (BIBEM) and poly(ethylene glycol) methyl ether methacrylate as monomer, inimer and hydrophilic comonomer, respectively, in the presence of Mn-2(CO)(10). The resulting polymers possess both hydrophobic and hydrophilic sequences offering many potential bio applications such as controlled drug delivery and release. Moreover, the resulting polymers contain also unreacted bromide groups in the final structure which allow postfunctionalization through copper(I)-catalyzed alkyne-azide cycloaddition "click" reactions.Öğe Visible light-induced synthesis of polysulfone-based graft copolymers by a grafting from approach(Wiley, 2020) Çiftçi, Mustafa; Tasdelen, Mehmet AtillaThe synthesis of polysulfone (PSU) graft copolymers by a two-step "grafting from" approach is described. First, a chlorofunctional PSU (PSU-Cl) is formed via chloromethylation of a commercial PSU. The formed polymers are used macroinitiator for the dimanganese decacarbonyl assisted free-radical polymerization of tert-butyl acrylate, methyl methacrylate, and styrene to give the desired graft copolymers. Moreover, amphiphilic graft copolymers are also formed via posthydrolyzation of poly(tert-butyl acrylate) containing graft copolymers. The intermediates at various stages and the ultimate graft copolymers are characterized by various analysis techniques. (c) 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 412-416
