Figure 6 - available from: Journal of Materials Science
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FT-IR spectra recorded for PGMA microspheres (Table S1, entry 3) and PGMA-NH2 microspheres, b X-ray photoelectron spectra recorded for PGMA microspheres (Table S1, entry 3) and PGMA-NH2 microspheres
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Herein, we report a photoinitiated RAFT dispersion polymerization for the preparation of highly monodisperse poly(glycidyl methacrylate) (PGMA) microspheres at room temperature. Fast polymerization rates were achieved, with near quantitative yields within 2 h of UV irradiation. The effect of reaction conditions (e.g., stabilizer concentration, mono...
Citations
... Glycidyl methacrylate (GlyMA), which is a commodity monomer, has been widely used for coatings, catalysis, biomedical analysis, biomolecular separation, and gene delivery. [35][36][37] The epoxy moiety can be functionalized with alcohols, thiols, amines, or proteins. In addition, epoxydiamine chemistry is an easy way to achieve covalent cross-linking, as studied by Armes, 16 Tan, 26 and Chen 38 et al. ...
Smart polymeric vesicles with both tertiary amine and epoxy functional groups were fabricated for the first timeviaa reversible addition-fragmentation chain transfer dispersion polymerization approach, using (2-(diisopropylamino)ethyl methacrylate (DIPEMA) and glycidyl methacrylate (GlyMA) in an ethanol-water mixture. Monitoring of thein situpolymerization revealed the low molecular weight distributions and the intermediate structures of spheres and worms, indicating an evolution in particle morphology. A phase diagram was constructed for reproducible fabrication of the vesicles, and copolymer composition was found to be more related to particle morphology. The vesicles exhibited superior structural stability for the cross-linking of the core through epoxydiamine chemistry, and intelligent pH responsibility due to the presence of the tertiary amine groups. The cross-linked vesicles showed good stability and reversibility during the swelling and shrinking cycles by switching the pH values, which endowed them with potential cell-like transmission functions. This research thus provides a method for producing structurally stable pH-responsive polymeric vesicles, and the reported vesicles are based on commercially available starting materials for possible industrial scale-up.
... In general, the chemical reduction method in the presence of polymer stabilizing agents allows accurately tracking the growth of NPs, effectively passivating the NP surface, obtaining a narrow distribution of the resulting NPs in size, and controlling their morphology. In recent years, polymers have been used effectively as stabilizing agents for the synthesis of various MPNs [1,[59][60][61][62]. As typical examples, we note various synthetic polymers such as poly(N-vinylpyrrolidone) (PVP) [63][64][65][66][67][68][69], polyethylene glycol (PEG) [70][71][72][73], poly (ethylene imine) (PEI) [74], polyvinyl chloride (PVC) [75], PAA [68,[76][77][78], polyacrylamide (PAAm) [79,80], poly(Nisopropylacrylamide) (PNIPAM) [81], sulfonated copolymers [82,83], conjugated polymers (CP), including polyaniline (PANI), polypyrrole (PPy), polythiophene (PT) and their derivatives [84,85], polyelectrolytes [86][87][88][89], poly(ionic liquids) (PILs) [44,90], polymer brushes [91][92][93][94][95][96], dendrimers [97] and some natural polymers such as starch [98], chitosan [99,100], chitin [101], cellulose derivatives [102], etc. ...
This review summarizes the latest advances in the preparation of metal-polymer nanocomposites by chemical reduction of metal ions in polymer matrices that are classified according to their functions as stabilizing agents, templates and reducing agents. Particular attention is paid to various factors affecting the size and morphology of particles, the composition and structure of metal-polymer nanocomposites. Problems and prospects of development of metal-polymer nanocomposites obtained by chemical reduction of metal ions are considered.
... Continuing the development of RAFT dispersion photopolymerization, Tan et al. turned their attention to macroRAFT agents (Fig. 28) to stabilize PMMA microspheres through in situ formation of block copolymers [194]. Variant strategies were designed by the same group involving poly(ethylene glycol) methacrylate macromonomer [195], a range of RAFT agents [196], encapsulation of lanthanide nanoparticles [197], formation of cross-linked particles [198], as well as glycidyl-functionalized particles for post-functionalization [199]. PISA combined with photoinitiation is the latest landmark in the development of dispersion photopolymerization. ...
Zero-VOC technologies combining ecological and economic efficiency are destined to occupy a growing place in the polymer economy. Today, Polymerization in dispersed systems and Photopolymerization are the two major key players. The hybrid technology based on photopolymerization in dispersed systems has emerged as the next technological frontier, not only to make processes even more efficient and eco-friendly, but also to expand the range of polymer products and properties. This review summarizes the current knowledge in research relevant to this field in an exhaustive way. Firstly, fundamentals of photoinitiated polymerization in dispersed systems are given to show the favourable context for developing this emerging technology, its specific features as well as the distinctive equipment and materials necessary for its implementation. Secondly, a state-of-the-art and critical review is provided according to the seven main processing methods in dispersed systems: emulsion, microemulsion, miniemulsion, dispersion, precipitation, suspension, and aerosol.
... Micron-sized polymeric microspheres have attracted much attention due to their broad applications in catalysis, molecular separation, molecular imprinting, Pickering emulsion, and biomedical analysis [1][2][3][4][5][6]. These polymeric microspheres are most commonly prepared using the seeded swelling method developed by Ugelstad [7] or the seeded emulsion polymerization developed by Vanderhoff [8]. ...
Herein, we report a photoinitiated reversible addition-fragmentation chain transfer (RAFT) dispersion copolymerization of methyl methacrylate (MMA) and methyl methacrylic (MAA) for the preparation of highly monodisperse carboxyl-functionalized polymeric microspheres. High rates of polymerization were observed, with more than 90% particle yields being achieved within 3 h of UV irradiation. Effects of reaction parameters (e.g., MAA concentration, RAFT agent concentration, photoinitiator concentration, and solvent composition) were studied in detail, and highly monodisperse polymeric microspheres were obtained in most cases. Finally, silver (Ag) composite microspheres were prepared by in situ reduction of AgNO3 using the carboxyl-functionalized polymeric microspheres as the template. The obtained Ag composite microspheres were able to catalyze the reduction of methylene blue (MB) with NaBH4 as a reductant.
... To improve the dispersion stability of AuNPs, researchers have loaded AuNPs onto various structural supporting materials, such as polymers [25,26] and inorganic materials [27,28]. In addition, the strong interaction between AuNPs and the supporting materials enables modification of the physical and chemical properties of the AuNPs [29]. ...
Loading of Au nanoparticles (AuNPs) onto environmentally sensitive polymer microgels is increasingly used to regulate their optical properties and catalytic activities. Herein, we synthesized composite polymer microgels composed of poly(N-isopropylacrylamide-co-3-methacryloxypropyltrimethoxysilane)/poly(acrylic acid) with a core–shell structure, and AuNPs were controllably loaded onto/into the network chains of the polymer microgels using seed-mediated growth. The prepared AuNPs composite materials possessed good pH sensitivity; the electromagnetic coupling between the AuNPs could thus be tuned via the swelling/deswelling of the polymer microgels under various acidic/alkaline conditions. More importantly, the coordination interaction between the carboxyl groups in the PAA chains and Cu²⁺ ions changed by varying the copper ion content under various pH conditions, thus enabling regulation of the localized surface plasmon resonance of the AuNPs. These structural features of the prepared composite microgels enabled to tailor the optical performance of the AuNPs by varying the pH of the surrounding medium.
... The obtained polymer nano-objects were further cross-linked or modified with fluorescent dyes using hydrazine. Glycidyl methacrylate (GMA) is a commodity mono mer that has been widely used in the areas of coating, catalysis, biomedical analysis, biomolecular separation, gene delivery, etc. [34][35][36][37][38][39] The epoxy moiety can be functionalized with alcohols, thiols, amines, or proteins. [40][41][42] However, it is really surprising that using GMA as the core-forming monomer of PISA has never been reported before. ...
Herein, a novel photoinitiated polymerization-induced self-assembly formulation via photoinitiated reversible addition-fragmentation chain transfer dispersion polymerization of glycidyl methacrylate (PGMA) in ethanol-water at room temperature is reported. It is demonstrated that conducting polymerization-induced self-assembly (PISA) at low temperatures is crucial for obtaining colloidal stable PGMA-based diblock copolymer nano-objects. Good control is maintained during the photo-PISA process with a high rate of polymerization. The polymerization can be switched between "ON" and "OFF" in response to visible light. A phase diagram is constructed by varying monomer concentration and degree of polymerization. The PGMA-based diblock copolymer nano-objects can be further cross-linked by using a bifunctional primary amine reagent. Finally, silver nanoparticles are loaded within cross-linked vesicles via in situ reduction, exhibiting good catalytic properties.
... Many novel preparation methods were also proposed, e.g., water sol-gel [28], UV-irradiation processes [19], the simple wet impregnation method [29], the organic-inorganic hybrid method [30], a hydrothermal approach [31], simple free radical polymerization [32], the ultraviolet-visible light irradiation process [33], and a novel hot press casting method [34]. In addition, the effects of reaction conditions (e.g., stabilizer concentration, monomer concentration, and solvent composition) on particle morphologies were studied in detail [35]. The organic-inorganic hybrid method is one of the most promising methods for fabricating superhydrophobic surfaces because of its low demand for equipment, simple operation, low cost, large-area fabrication, and easy realization of industrialized production [36]. ...
A method to prepare novel organic-inorganic hydrophobic nanocomposite films was proposed by a site-specific polymerization process. The inorganic part, the core of the nanocomposite, is a ternary SiO2–Al2O3–TiO2 nanoparticles, which is grafted with methacryloxy propyl trimethoxyl silane (KH570), and wrapped by fluoride and siloxane polymers. The synthesized samples are characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectrscopy, X-ray diffractometry (XRD), contact angle meter (CA), and scanning electron microscope (SEM). The results indicate that the novel organic-inorganic hydrophobic nanocomposite with a core-shell structure was synthesized successfully. XRD analysis reveals the nanocomposite film has an amorphous structure, and FTIR analysis indicates the nanoparticles react with a silane coupling agent (methacryloxy propyl trimethoxyl silane KH570). Interestingly, the morphology of the nanoparticle film is influenced by the composition of the core. Further, comparing with the film synthesized by silica nanoparticles, the film formed from SiO2–Al2O3–TiO2 nanoparticles has higher hydrophobic performance, i.e., the contact angle is greater than 101.7°. In addition, the TEM analysis reveals that the crystal structure of the particles can be changed at high temperatures.
The development of bioactive components as a delivery system with the use of advanced nanoscience is opening new therapeutic avenues for the management of various diseases. Among recent novel applications, plant phytopharmaceuticals and nutraceuticals are the fastest growing areas of nanotechnology-based research for effective public healthcare. Bioactive compounds, either encapsulated or in entrapped form within novel drug delivery systems are reported as a booster treatment for the various chronic infections and life-threatening diseases, including cancer, cardiovascular disorders, hypertension, diabetes, asthma, malaria, microbial infections, immune disorders, and gastrointestinal disorders. Recently, considerable progress surged in understanding the factors associated with these diseases. A variety of nanoscience-based formulations such as polymeric matrix nanoparticles, aerosol inhalers/nebulizers nanoemulsion, and vesicular carrier systems including liposome, phytosome, transfersome, herbosome, ethosome, niosome, have proven valuable in the delivery of bioactive materials. Moreover, the scientific community had reported that the herbs and herbal bioactive compounds have notable recompense compared to the conventional method of delivering phytopharmaceuticals and plant extracts, with enhanced solubility, bioavailability, stability, tissue distribution, abridged toxicity, improved pharmacological efficacy, and protection from physicochemical degradation. The current chapter focuses on the carrier-based delivery of bioactive as a booster with advanced using nanoscience, such as nanoemulsion and vesicular drug delivery systems. In addition, the chapter also elaborates patented technologies along with potential bioactive products available in the market.
