Photomediated Atom Transfer Radical Polymerization (photoATRP) is an activator regeneration method, which allows for the controlled synthesis of well-defined polymers via light irradiation. Traditional photoATRP is often limited by the need for high-energy ultraviolet or violet light. These could negatively affect the control and selectivity of the polymerization, promote side reactions, and may not be applicable to biologically relevant systems.
View Article and Find Full Text PDFIn atom transfer radical polymerization (ATRP), dormant alkyl halides are intermittently activated to form growing radicals in the presence of a Cu/L/X-Cu/L (activator/deactivator) catalytic system. Recently developed very active copper complexes could decrease the catalyst concentration to ppm level. However, unavoidable radical termination results in irreversible oxidation of the activator to the deactivator species, leading to limited monomer conversions.
View Article and Find Full Text PDFSolid-phase polymer synthesis, historically rooted in peptide synthesis, has evolved into a powerful method for achieving sequence-controlled macromolecules. This study explores solid-phase polymer synthesis by covalently immobilizing growing polymer chains onto a poly(ethylene glycol) (PEG)-based resin, known as ChemMatrix (CM) resin. In contrast to traditional hydrophobic supports, CM resin's amphiphilic properties enable swelling in both polar and nonpolar solvents, simplifying filtration, washing, and drying processes.
View Article and Find Full Text PDFObjective: This study aimed to compare the criminal, sociodemographic and clinical characteristics, paraphilic behaviors, sexual attitudes, gender perceptions, and rape-related beliefs of people assessed for criminal liability for rape against adults and children.
Method: The study compared 40 people investigated for criminal liability for rape against an adult (RAA) with 40 individuals investigated for criminal liability for crime of rape against a child (RAC), and 43 age, sex and education matched individuals without any sexual crime history using the Structured Clinical Interview form for DSM-5 disorders, Hendrick Brief Sexual Attitude Scale, Gender Perception Scale, Illinois Rape Myth Acceptance Scale, and Barratt Impulsiveness Scale-11.
Results: All participants were male.
Carbon nanomaterials, specifically carbon dots and carbon nitrides, play a crucial role as heterogeneous photoinitiators in both radical and cationic polymerization processes. These recently introduced materials offer promising solutions to the limitations of current homogeneous systems, presenting a novel approach to photopolymerization. This review highlights the preparation and photocatalytic performance of these nanomaterials, emphasizing their application in various polymerization techniques, including photoinduced i) free radical, ii) RAFT, iii) ATRP, and iv) cationic photopolymerization.
View Article and Find Full Text PDFA straightforward approach is employed to synthesize methylene-bridged poly(hetero aromatic)s based on furan, pyrrole, thiophene, and thiophene derivatives. The process involves an electrophilic aromatic substitution reaction facilitated by a visible light-initiated system consisting of manganese decacarbonyl and an iodonium salt. The approach mainly relies on the formation of halomethylium cation, the attack of this cation to heteroaromatic, regeneration of methylium cation on the heteroaromatic, and reactivity differences between halomethylium and heteroaromatic methylium cations for successful polymerizations.
View Article and Find Full Text PDFFast bulk depolymerization of poly(-butyl methacrylate) and poly(methyl methacrylate), prepared by atom transfer radical polymerization (ATRP), is reported in the temperature range between 150 and 230 °C. Depolymerization of Cl-terminated polymethacrylates was catalyzed by a CuCl/TPMA complex (0.022 or 0.
View Article and Find Full Text PDFIntroduction: Despite the similarities in poor social competence and clinical manifestations of poor social behavior, no study has compared the theory of mind performance between social anxiety disorder (SAD) and schizophrenia, considering the effect of social-evaluative anxiety and neurocognitive functions. In our study, we aimed to compare the theory of mind functions and social-evaluative anxiety between patients with SAD and schizophrenia and healthy controls and to examine the relationship between the theory of mind, neurocognitive skills, and social-evaluative anxiety.
Methods: Thirty-four consecutive patients with schizophrenia, 29 patients with SAD, and 30 controls matched by age, education level, and sex were enrolled in the study.
This study aims to compare the Theory of Mind (ToM) functions in the siblings and offspring of female Schizophrenia patients in an evaluation of the association between neurocognitive functions and ToM. A battery of ToM tests (Reading the Mind in the Eyes Test, Hinting Test and Faux Pas Test) and neurocognitive tests (Digit Span Test, Corsi Block Test, Digit Symbol Substitution Test, Rey's Auditory Verbal Learning Test, Trail Making Test, The Stroop Test, Wisconsin Card Sorting Test) were used to assess 31 offspring, 29 siblings of female schizophrenia patients and 28 healthy controls (HC). When the ToM functions of the offspring, siblings and HC groups in the present study are compared, no significant difference is identified between the offspring and sibling groups in Hinting, Faux Pas and Eyes tests, while Hinting test performance of the sibling group was significantly lower than those of the HCs.
View Article and Find Full Text PDFA versatile strategy for the fabrication of block copolymers by the combination of two discrete living polymerization techniques─reversible complexation mediated living radical polymerization (RCMP) and photoinduced radical oxidation addition deactivation (PROAD) processes─is reported. First, RCMP is conducted to yield poly(methyl methacrylate) with iodide end groups (PMMA-I). In the following step, PMMA-I is used as macroinitiator for living PROAD cationic polymerization of isobutyl vinyl ether.
View Article and Find Full Text PDFIn the drive toward the development of efficient and stable inorganic semiconductor materials with broadband solar absorption ability to induce various photochemical processes is a highly attractive research field. In this study, two-dimensional (2D) few-layer black phosphorus (BP) exfoliated in a solvent is utilized as photocatalyst to initiate the polymerization of various monomers under visible and near-IR (NIR) light irradiation. Upon the light exposure, few-layer BP generates excited electrons and holes, which undergo electron transfer reactions with the onium salts to form free radicals capable of initiating free radical polymerization.
View Article and Find Full Text PDFThe application of photochemistry in polymer synthesis is of interest due to the unique possibilities offered compared to thermochemistry, including topological and temporal control, rapid polymerization, sustainable low-energy processes, and environmentally benign features leading to established and emerging applications in adhesives, coatings, adaptive manufacturing, etc. In particular, the utilization of photochemistry in controlled/living polymerizations often offers the capability for precise control over the macromolecular structure and chain length in addition to the associated advantages of photochemistry. Herein, the latest developments in photocontrolled living radical and cationic polymerizations and their combinations for application in polymer syntheses are discussed.
View Article and Find Full Text PDFVarious ligation processes have recently become a powerful tool in synthetic polymer chemistry. Herein, the use of a new photochemical ligation process as a versatile approach for the cross-linking polymerization, functionalization of polymer chain ends, and surface modification of various materials such as silica and graphene oxide, is demonstrated. The process is based on the formation of urethane linkages by the reaction of photochemically in situ generated isocyanates from benzoyl azides with hydroxyl moieties in the presence of organobase, bicyclo[2.
View Article and Find Full Text PDFA novel visible light induced step-growth polymerization to form poly(phenylene methylene) by electrophilic aromatic substitution reactions is described. The effect of different nucleophilic aromatic molecules on polymerization has been investigated. The possibility of combining step-growth polymerization with conventional free radical and free radical promoted cationic polymerizations through photoinduced chain-end activation has been demonstrated.
View Article and Find Full Text PDFMacromol Rapid Commun
April 2021
A new visible light induced step-growth polymerization of dibromoxylene, and diols using dimanganese decacarbonyl and diphenyliodonium salt is described. The polymerization is suggested to proceed by substitution reaction between dixylenium cations formed upon visible light irradiation in the presence of dimanganese decacarbonyl and diphenyl iodonium salt. For the described substitution reaction with diols as nucleophilic component, the scope of the process is studied.
View Article and Find Full Text PDFDes Monomers Polym
August 2020
A completely metal-free and environmentally friendly strategy is demonstrated for the preparation of graft copolymers by combining photoinduced Atom Transfer Radical Polymerization (ATRP) and Ring Opening Polymerization (ROP). Polymerizations are simultaneously realized in a one-pot manner. For this purpose, bare vinyl monomers, vinyl monomers with hydroxyl functional groups, and lactone monomers were simultaneously polymerized under visible light using specific catalysts.
View Article and Find Full Text PDFPolymers (Basel)
September 2019
A completely metal-free strategy is demonstrated for the preparation of star copolymers by combining atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) for the syntheses of block copolymers. These two different metal-free controlled/living polymerizations are simultaneously realized in one reaction medium in an orthogonal manner. For this purpose, a specific core with functional groups capable of initiating both polymerization types is synthesized.
View Article and Find Full Text PDFThere is an urgent demand worldwide for the development of highly selective adsorbents and sensors of heavy metal ions and other organic pollutants. Within these environmental and public health frameworks, we are combining the salient features of clays and chelatant polymers to design selective metal ion adsorbents. Towards this end, the ion imprinting approach has been used to develop a novel nanohybrid material for the selective separation of Cu ions in an aqueous solution.
View Article and Find Full Text PDFA novel method for photochemical step-growth synthesis of poly( N-ethylcarbazole) (PEC) via consecutive diphenyl iodonium hexafluorophospate (PhIPF) mediated electron transfer and coupling reactions is reported. The photoinduced electron transfer reaction of the excited N-ethylcarbazole (EC) in the presence of PhIPF as the oxidizing salt proceeded efficiently giving EC radical cations (EC). Subsequently, the protons released concomitantly with coupling of two EC radical cations.
View Article and Find Full Text PDFMacromol Rapid Commun
July 2016
Thioxanthone (TX) and its derivatives, which are widely used as photoinitiators in UV curing technology, hold promising research interest in biological applications. In particular, the use of TXs as anticancer agent has recently been manifested as an outstanding additional property of this class of molecules. Incorporation of TX molecules into specially designed polymers widens their practical use in such applications.
View Article and Find Full Text PDFA novel one-component type II polymeric photoinitiator, poly(vinyl alcohol)-thioxanthone (PVA-TX), is synthesized by a simple acetalization process and characterized. PVA-TX enables photopolymerization of methyl methacrylate and acrylamide in both organic and aqueous media. Photopolymerization proceeds even in the absence of a co-initiator since PVA-TX possesses both chromophoric and hydrogen donating sites in the structure.
View Article and Find Full Text PDFA novel visible light sensitive photoinitiator system for the cationic polymerization of typical monomers, for example, of oxiranes, such as cyclohexene oxide, vinyl ethers, such as iso-butyl vinyl ether, and other vinyl monomers, such as -vinylcarbazole, using fullerene derivatives is described. The cationic polymerization of these monomers was initiated at room temperature upon irradiation in the visible region (λ > 400 nm) in bulk or chlorobenzene solutions with polystyrene-C (PS-C) adduct or bare C, respectively, in the presence of oxidizing salts such as silver hexafluorophosphate (AgPF) and diphenyliodonium hexafluorophosphate (PhIPF). A feasible mechanism, as correlated with optical absorption measurements, free energy changes (Δ), and proton scavenging studies, involves formation of exciplex by the absorption of light in the first step.
View Article and Find Full Text PDFIn this paper we describe a novel methodology for grafting polymers via radical photopolymerization initiated on gold surfaces by aryl layers from diazonium salt precursors. The parent 4-(dimethylamino)benzenediazonium salt was electroreduced on a gold surface to provide 4-(dimethylamino)phenyl (DMA) hydrogen donor layers; free benzophenone in solution was used as a photosensitizer to strip hydrogen from the grafted DMA. This system permitted efficient surface initiation of photopolymerization of 2-hydroxyethyl methacrylate.
View Article and Find Full Text PDFMacromol Rapid Commun
December 2011
Current preparation methods for hydrogels based on redox or photopolymerization of water soluble monomers are simple to use, and flexible, but have the drawback of requiring additional modification steps for tuning or introducing properties for specific purposes. We have devised a simple and rapid synthetic strategy to prepare hydrogels possessing reactive sites to incorporate any molecules of interest by "Click Chemistry". The strategy is based on the use of propargyl acrylamide (PAm) as comonomer together with acrylamide (AAm) and N,N'-methylene bisacrylamide (BAAm) as crosslinker in photoinitiated polymerization.
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