Crystallization-Driven Controlled 2D Self-Assemblies via Aqueous RAFT Emulsion Polymerization

Aqueous emulsion polymerization is a robust technique for preparing nanoparticles of block copolymers; however, it typically yields spherical nanoassemblies. The scale preparation of nanoassemblies with nonspherical high-order morphologies is a challenge, particularly 2D core-shell nanosheets. In this study, the polymerization-induced self-assembly (PISA) and crystallization-driven self-assembly (CDSA) are combined to demonstrate the preparation of 2D nanosheets and their aggregates via aqueous reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization. First, the crucial crystallizable component for CDSA, hydroxyethyl methacrylate polycaprolactone (HPCL) macromonomer is synthesized by ring opening polymerization (ROP). Subsequently, the RAFT emulsion polymerization of HPCL is conducted to generate crystallizable nanomicelles by a grafting-through approach. This PISA process simultaneously prepared spherical latices and bottlebrush block copolymers comprising poly(N',N'-dimethylacrylamide)-block-poly(hydroxyethyl methacrylate polycaprolactone) (PDMA-b-PHPCL). The latexes are now served as seeds for inducing the formation of 2D hexagonal nanosheets, bundle-shaped and flower-like aggregation via the CDSA of PHPCL segments and unreacted HPCL during cooling. Electron microscope analysis trace the morphology evolution of these 2D nanoparticles and reveal that an appropriate crystallized component of PHPCL blocks play a pivotal role in forming a hierarchical structure. This work demonstrates significant potential for large-scale production of 2D nanoassemblies through RAFT emulsion polymerization.

Renewable and Functional Latexes Synthesized by Polymerization-Induced Self-Assembly for UV-Curable Films

After the development of polymer coatings and films based on renewable resources, there remains a challenge of combining the advantages of water-borne acrylic latexes with the excellent physical properties of cross-linked solvent-borne coatings. After polymerization, the renewable 4-oxocyclopentenyl acrylate (4CPA) is capable of undergoing photocyclodimerization under UV light, yielding a cross-linked polyacrylate. In this work, we investigate the polymerization-induced self-assembly (PISA) of 4CPA with several renewable acrylic monomers in the presence of a macro-RAFT agent. The produced latexes have a small particle size, good colloidal stability, and are free of volatile organic compounds. After film formation and UV curing, flexible to rigid films can be obtained depending on the monomer composition and UV irradiation time. The cross-linked films show promise as oil and water barriers in paper coating applications. This work outlines the development and application of renewable and functional cross-linkable latexes synthesized by PISA.

Synthesis of Polymers with Narrow Molecular Mass Distribution through Interface-Initiated Room-Temperature Polymerization in Emulsion Gels

Homopolymers of n-butyl acrylate, methyl methacrylate, styrene, and their random copolymers were prepared via interface-initiated polymerization of emulsion gels at 20 °C. The polymerization was conducted in a free radical polymerization manner without inert gas protection. Compared with the polymers synthesized at 60 °C, the polymerization of emulsion gels at 20 °C produced homo- and copolymers with a higher molecular mass and a narrower molecular mass distribution. The polydispersity indices for the polymers synthesized at 20 °C were found to be between 1.12 and 1.37. The glass transition temperatures for the as-synthesized butyl acrylate copolymers agree well with the prediction from the Gordon-Taylor equation. Interface-initiated room-temperature polymerization is a robust, energy-saving polymerization technique for synthesizing polymers with a narrow molecular mass distribution.

Histidine-Functionalized Diblock Copolymer Nanoparticles Exhibit Enhanced Adsorption onto Planar Stainless Steel

RAFT aqueous emulsion polymerization of isopropylideneglycerol monomethacrylate (IPGMA) is used to prepare a series of PGEO5MA46 -PIPGMAy nanoparticles, where PGEO5MA is a hydrophilic methacrylic steric stabilizer block bearing pendent cis-diol groups. TEM studies confirm a spherical morphology while dynamic light scattering (DLS) analysis indicated that the z-average particle diameter can be adjusted by varying the target degree of polymerization for the core-forming PIPGMA block. Periodate oxidation is used to convert the cis-diol groups on PGEO5MA46 -PIPGMA500 and PGEO5MA46 -PIPGMA1000 nanoparticles into the analogous aldehyde-functionalized nanoparticles, which are then reacted with histidine via reductive amination. In each case, the extent of functionalization is more than 99% as determined by 1 H NMR spectroscopy. Aqueous electrophoresis studies indicate that such derivatization converts initially neutral nanoparticles into zwitterionic nanoparticles with an isoelectric point at pH 7. DLS studies confirm that such histidine-derivatized nanoparticles remain colloidally stable over a wide pH range. A quartz crystal microbalance is employed at 25°C to assess the adsorption of both the cis-diol- and histidine-functionalized nanoparticles onto planar stainless steel at pH 6. The histidine-bearing nanoparticles adsorb much more strongly than their cis-diol counterparts. For the highest adsorbed amount of 70.5 mg m-2 , SEM indicates a fractional surface coverage of 0.23 for the adsorbed nanoparticles.

Multiblock copolymer synthesis via RAFT emulsion polymerization

A multiblock copolymer is a polymer of a specific structure that consists of multiple covalently linked segments, each comprising a different monomer type. The control of the monomer sequence has often been described as the "holy grail" of synthetic polymer chemistry, with the ultimate goal being synthetic access to polymers of a "perfect" structure, where each monomeric building block is placed at a desired position along the polymer chain. Given that polymer properties are intimately linked to the microstructure and monomer distribution along the constituent chains, it goes without saying that there exist seemingly endless opportunities in terms of fine-tuning the properties of such materials by careful consideration of the length of each block, the number and order of blocks, and the inclusion of monomers with specific functional groups. The area of multiblock copolymer synthesis remains relatively unexplored, in particular with regard to structure-property relationships, and there are currently significant opportunities for the design and synthesis of advanced materials. The present review focuses on the synthesis of multiblock copolymers via reversible addition-fragmentation chain transfer (RAFT) polymerization implemented as aqueous emulsion polymerization. RAFT emulsion polymerization offers intriguing opportunities not only for the advanced synthesis of multiblock copolymers, but also provides access to polymeric nanoparticles of specific morphologies. Precise multiblock copolymer synthesis coupled with self-assembly offers material morphology control on length scales ranging from a few nanometers to a micrometer. It is imperative that polymer chemists interact with physicists and material scientists to maximize the impact of these materials of the future.

Brush-like Polyaniline with Optical and Electroactive Properties at Neutral pH and High Temperature

In this research, a brush-like polyaniline (poly(2-acrylamide-2-methyl-1-propanesulfonate)-g-polyaniline)-b-poly(N-vinylcarbazole) (BL PAni) was developed as a strategy to overcome the limited processability and dedoping above pH 4 of conventional polyaniline (PAni). For the BL PAni synthesis, RAFT polymerization (homopolymer), RAFT-mediated surfactant-free emulsion polymerization (block copolymer), and interfacial oxidative polymerization were applied to graft the PAni chains. NMR and FT-IR spectroscopies were performed to confirm the structural elucidation of the reaction pathways, while the thermal properties were analyzed by TGA and DSC. Notably, the BL PAni presents absorption throughout the visible region and up to the near-infrared, showing dedoping resistance at up to 80 °C and at a neutral pH. The absorption range of the BL PAni, block copolymer, and homopolymer were studied by UV–Vis spectroscopy in solid-state and dispersion/solution, highlighting BL PAni and poly(anilinium 2-acrylamide-2-methyl-1-propanesulfonate)-b-poly(N-vinylcarbazole) (PAAMP-b-PVK) due to the π-stacking between the anilinium and carbazole groups. The cyclic voltammetry confirmed the persistence of electroactivity at a pH near 7.

Investigation of construction and characterization of carboxymethyl chitosan - sodium alginate nanoparticles to stabilize Pickering emulsion hydrogels for curcumin encapsulation and accelerating wound healing

Limitations in compatibility and effectiveness in delivering bioactive compounds often make it prohibitively difficult to apply Pickering emulsions in wound dressing. In this research, we prepared Pickering emulsion composite hydrogels based on carboxymethyl chitosan - sodium alginate (CMCS-SA) nanoparticles (NPs) stabilized Pickering emulsions, poloxamer 407 (PLX), and curcumin (CUR). CMCS-SA NPs were prepared and used to stabilize Pickering emulsion. The stability of Pickering emulsion improved with the increase of the concentration of NPs, and was highly sensitive to ionic strength change. This Pickering emulsion remained stable at various temperatures. After curcumin were introduced into the emulsion, 0.6% CMCS-SA NPs Pickering emulsion showed controlled release of curcumin in vitro. The CMCS-SA-PLX-CUR hydrogels also exhibited smooth surface and dense structure. This composite hydrogels has antibacterial properties against Escherichia coli and Staphylococcus aureus. Moreover, the CMCS-SA-PLX-CUR hydrogels improved wound healing and increased expression of Ki67 and CD31. RT-qPCR results indicated that the mRNA levels of α-SMA and TGF-β1 in the CMCS-SA-PLX-CUR group were downregulated, while the mRNA levels of TGF-β3 increased. The present study suggests that the potentials of CMCS-SA-PLX-CUR hydrogels are promising in protecting bioactive components and wound care management.

Exploring Various Techniques for the Chemical and Biological Synthesis of Polymeric Nanoparticles

Nanoparticles (NPs) have remarkable properties for delivering therapeutic drugs to the body's targeted cells. NPs have shown to be significantly more efficient as drug delivery carriers than micron-sized particles, which are quickly eliminated by the immune system. Biopolymer-based polymeric nanoparticles (PNPs) are colloidal systems composed of either natural or synthetic polymers and can be synthesized by the direct polymerization of monomers (e.g., emulsion polymerization, surfactant-free emulsion polymerization, mini-emulsion polymerization, micro-emulsion polymerization, and microbial polymerization) or by the dispersion of preformed polymers (e.g., nanoprecipitation, emulsification solvent evaporation, emulsification solvent diffusion, and salting-out). The desired characteristics of NPs and their target applications are determining factors in the choice of method used for their production. This review article aims to shed light on the different methods employed for the production of PNPs and to discuss the effect of experimental parameters on the physicochemical properties of PNPs. Thus, this review highlights specific properties of PNPs that can be tailored to be employed as drug carriers, especially in hospitals for point-of-care diagnostics for targeted therapies.

Electrochemically Initiated Synthesis of Polyacrylamide Microgels and Core-shell Particles

Herein, we developed a simple procedure for synthesizing micrometer-sized microgel particles as a suspension in an aqueous solution and thin films deposited as shells on different inorganic cores. A sufficiently high constant potential was applied to the working electrode to commence the initiator decomposition that resulted in gelation. Under hydrodynamic conditions, this initiation allowed preparing different morphology microgels at room temperature. Importantly, neither heating nor UV-light illumination was needed to initiate the polymerization. Moreover, thin films of the cross-linked gel were anchored on different core substrates, including silica and magnetic nanoparticles. Scanning electron microscopy and transmission electron microscopy imaging confirmed the microgel particles' and films' irregular shape and porous structure. Energy-dispersive X-ray spectroscopy indicated that the core coating with the microgel film was successful. Dynamic light scattering measured the micrometer size of gel particles with different combinations of acrylic monomers. Thermogravimetric analysis and the first-derivative thermogravimetric analysis revealed that the microgels' thermal stability of different compositions was different. Fourier-transform infrared and 13C NMR spectroscopy showed successful copolymerization of the main, functional, and cross-linking monomers.

Micellar drug delivery vehicles formed from amphiphilic block copolymers bearing photo-cross-linkable cyclopentenone side groups

UV core cross-linkable amphiphilic block copolymers containing cyclopentenone side groups on the hydrophobic backbone were synthesized and drug delivery experiments were done with the cancer therapeutic drug Doxorubicin.

Application of surfactants in papermaking industry and future development trend of green surfactants

In this work, the application of chemical surfactants, including cooking aids, detergents, surface sizing agents, and deinking agents as core components, is introduced in the wet end of pulping and papermaking. This method for the combined application of enzymes and surfactants has expanded, promoting technological updates and improving the effect of surfactants in practical applications. Finally, the potential substitution of green surfactants for chemical surfactants is discussed. The source, classification, and natural functions of green surfactants are introduced, including plant extracts, biobased surfactants, fermentation products, and woody biomass. These green surfactants have advantages over their chemically synthesized counterparts, such as their low toxicity and biodegradability. This article reviews the latest developments in the application of surfactants in different paper industry processes and extends the methods of use. Additionally, the application potential of green surfactants in the field of papermaking is discussed. KEY POINTS: • Surfactants as important chemical additives in papermaking process are reviewed. • Deinking technologies by combined of surfactants and enzymes are reviewed. • Applications of green surfactant in papermaking industry are prospected.

How the Reactive End Group of Macro-RAFT Agent Affects RAFT-Mediated Emulsion Polymerization-Induced Self-Assembly

Polymerization-induced self-assembly via reversible addition-fragmentation chain transfer (RAFT)-mediated emulsion polymerization is an emerging method in which macro-RAFT agents are chain extended with hydrophobic monomers in water to form block copolymer nano-objects. However, almost all RAFT-mediated emulsion polymerizations are limited to AB diblock copolymers by using monofunctional macro-RAFT agents with non-reactive end groups. In this study, the first investigation on how the reactive end group of macro-RAFT agent affects RAFT-mediated emulsion polymerization is reported. Three macro-RAFT agents with different end groups are synthesized and employed in RAFT-mediated emulsion polymerization. Effects of end groups on morphologies of block copolymer nano-objects and polymerization process are studied. Block copolymer nano-objects prepared by using an asymmetric difunctional macro-RAFT agent can be functionalized by further chain extension on the surface. It is expected that the current study will not only expand the scope of RAFT-mediated emulsion polymerization, but also provide a novel strategy to prepare functional polymer nanoparticles.

Cellulose nanocrystals in cancer diagnostics and treatment

Cancer is currently a major threat to public health, being among the principal causes of death to the global population. With carcinogenesis mechanisms, cancer invasion, and metastasis remaining blurred, cancer diagnosis and novel drug delivery approaches should be developed urgently to enable management and treatment. A dream break-through would be a non-invasive instantaneous monitoring of cancer initiation and progression to fast-track diagnosis for timely specialist treatment decisions. These innovations would enhance the established treatment protocols, unlimited by evasive biological complexities during tumorigenesis. It is therefore contingent that emerging and future scientific technologies be equally biased towards such innovations by exploiting the apparent properties of new developments and materials especially nanomaterials. CNCs as nanomaterials have undisputable physical and excellent biological properties that enhanced their interest as biomedical materials. This article therefore highlights CNCs utility in cancer diagnosis and therapy. Their extraction, properties, modification, in-vivo/in-vitro medical applications, biocompatibility, challenges and future perspectives are precisely discussed.

Interactions of core cross-linked poly(2-oxazoline) and poly(2-oxazine) micelles with immune cells in human blood

Water-soluble poly(cyclic imino ether)s (PCIEs) have emerged as promising biocompatible polymers for nanomedicine applications in recent years. Despite their generally accepted stealth properties, there has been no comprehensive evaluation of their interactions with primary immune cells in human blood. Here we present a library of core cross-linked micelles (CCMs) containing various PCIE shells. Well-defined high molar mass CCMs (M_n > 175 kDa, Р< 1.2) of similar diameter (~20 nm) were synthesised using a cationic ring-opening polymerisation (CROP) - surfactant-free reversible addition-fragmentation chain-transfer (RAFT) emulsion polymerisation strategy. The stealth properties of the different PCIE CCMs were assessed employing a whole human blood assay simulating the complex blood environment. Cell association studies revealed lower associations of poly(2-methyl-2-oxazoline) (PMeOx) and poly(2-ethyl-2-oxazoline) (PEtOx) CCMs with blood immune cells compared to the respective poly(2-oxazine) (POz) CCMs. Noteworthy, PMeOx CCMs outperformed all other reported CCMs, showing overall low associations and only negligible differences in the presence and absence of serum proteins. This study highlights the importance of investigating individual nanomaterials under physiologically relevant conditions and further strengthens the position of PMeOx as a highly promising stealth material for biomedical applications.

Encapsulation by Directed PISA: RAFT-Based Polymer-Vesiculated Pigment for Opacity Enhancement in Paint Films

A novel method is demonstrated to encapsulate titanium dioxide pigment using directed polymerization-induced self-assembly (PISA) with reversible addition-fragmentation chain-transfer (RAFT) controlled emulsion polymerization. The polymerization is carried out in a batch process in which both styrene (Sty) and the pigment are emulsified using triblock amphiphilic macro-RAFT copolymers as stabilizers. RAFT-controlled chain growth leads to directed lamellar self-assembly, forming polystyrene (PS) shells' encapsulating pigment particles with 100% efficiency. The pigment resides either at centers of single-void vesicles or within the interior of multivoid vesiculated particles. The presence of complex morphologies such as spherical particles, nanofibers, nanoplatelets, and polymer vesicles confirms the PISA pathway. The process is optimized to preferably produce polymer-vesiculated pigment for use as an enhanced opacifier in water-based paint.

RAFT dispersion polymerization of N,N-dimethylacrylamide in a series of n-alkanes using a thermoresponsive poly(tert-octyl acrylamide) steric stabilizer

Poly(tert-octyl acrylamide)-poly(N,N-dimethylacrylamide) nanoparticles are prepared by RAFT dispersion polymerization at 70 °C in various n-alkanes. Thermoreversible flocculation occurs in higher n-alkanes on cooling to 20 °C.

Initiation of RAFT Polymerization: Electrochemically Initiated RAFT Polymerization in Emulsion (Emulsion eRAFT), and Direct PhotoRAFT Polymerization of Liquid Crystalline Monomers

We report on two important advances in radical polymerization with reversible addition–fragmentation chain transfer (RAFT polymerization). (1) Electrochemically initiated emulsion RAFT (eRAFT) polymerization provides rapid polymerization of styrene at ambient temperature. The electrolytes and mediators required for eRAFT are located in the aqueous continuous phase separate from the low-molar-mass-dispersity macroRAFT agent mediator and product in the dispersed phase. Use of a poly(N,N-dimethylacrylamide)-block-poly(butyl acrylate) amphiphilic macroRAFT agent composition means that no added surfactant is required for colloidal stability. (2) Direct photoinitiated (visible light) RAFT polymerization provides an effective route to high-purity, low-molar-mass-dispersity, side chain liquid-crystalline polymers (specifically, poly(4-biphenyl acrylate)) at high monomer conversion. Photoinitiation gives a product free from low-molar-mass initiator-derived by-products and with minimal termination. The process is compared with thermal dialkyldiazene initiation in various solvents. Numerical simulation was found to be an important tool in discriminating between the processes and in selecting optimal polymerization conditions.

Achieving molecular weight distribution shape control and broad dispersities using RAFT polymerizations

Metered additions of chain transfer agents are used to control molecular weight distribution (MWD) features in reversible addition-fragmentation chain-transfer polymerizations, giving polymers with tailored MWD shapes and dispersities as high as 6.2.

Surfactant-free emulsion polymerization of vinylidene fluoride mediated by RAFT/MADIX reactive poly(ethylene glycol) polymer chains

Vinylidene fluoride (VDF) emulsion polymerization is conducted in the presence of xanthate-end functionalized poly(ethylene glycol)s leading to stable PVDF latexes.

Polymerization-induced self-assembly via RAFT in emulsion: effect of Z-group on the nucleation step

It is demonstrated that the nature of the Z-group of trithiocarbonate RAFT agents can have a major effect on the nucleation step of aqueous RAFT PISA performed as emulsion polymerization.

Aqueous emulsion polymerizations of methacrylates and styrene via reversible complexation mediated polymerization (RCMP)

Aqueous emulsion polymerization via reversible complexation mediated living radical polymerization yielded low-dispersity poly(methyl methacrylate)s and polystyrenes.

Biocatalytic nanoparticles for the stabilization of degassed single electron transfer-living radical pickering emulsion polymerizations

Synthetic polymers are indispensable in many different applications, but there is a growing need for green processes and natural surfactants for emulsion polymerization. The use of solid particles to stabilize Pickering emulsions is a particularly attractive avenue, but oxygen sensitivity has remained a formidable challenge in controlled polymerization reactions. Here we show that lignin nanoparticles (LNPs) coated with chitosan and glucose oxidase (GOx) enable efficient stabilization of Pickering emulsion and in situ enzymatic degassing of single electron transfer-living radical polymerization (SET-LRP) without extraneous hydrogen peroxide scavengers. The resulting latex dispersions can be purified by aqueous extraction or used to obtain polymer nanocomposites containing uniformly dispersed LNPs. The polymers exhibit high chain-end fidelity that allows for production of a series of well-defined block copolymers as a viable route to more complex architectures.

Biofunctional Polymer Coated Au Nanoparticles Prepared via RAFT-Assisted Encapsulating Emulsion Polymerization and Click Chemistry

The use of reversible addition-fragmentation chain transfer (RAFT)-assisted encapsulating emulsion polymerization (REEP) has been explored to prepare diverse types of colloidal stable core-shell nanostructures. A major field of application of such nanoparticles is in emergent nanomedicines, which require effective biofunctionalization strategies, in which their response to bioanalytes needs to be firstly assessed. Herein, functional core-shell nanostructures were prepared via REEP and click chemistry. Thus, following the REEP strategy, colloidal gold nanoparticles (Au NPs, d = 15 nm) were coated with a poly(ethylene glycol) methyl ether acrylate (PEGA) macroRAFT agent containing an azide (N3) group to afford N3-macroRAFT@Au NPs. Then, chain extension was carried out from the NPs surface via REEP, at 44 °C under monomer-starved conditions, to yield N3-copolymer@Au NPs-core-shell type structures. Biotin was anchored to N3-copolymer@Au NPs via click chemistry using an alkynated biotin to yield biofunctionalized Au nanostructures. The response of the ensuing biotin-copolymer@Au NPs to avidin was followed by visible spectroscopy, and the copolymer-biotin-avidin interaction was further studied using the Langmuir-Blodgett technique. This research demonstrates that REEP is a promising strategy to prepare robust functional core-shell plasmonic nanostructures for bioapplications. Although the presence of azide moieties requires the use of low polymerization temperature, the overall strategy allows the preparation of tailor-made plasmonic nanostructures for applications of biosensors based on responsive polymer shells, such as pH, temperature, and photoluminescence quenching. Moreover, the interaction of biotin with avidin proved to be time dependent.

Polymer-encapsulation of iron oxide clusters using macroRAFT block copolymers as stabilizers: tuning of the particle morphology and surface functionalization

We report the successful synthesis of superparamagnetic latex particles with a high fraction of magnetic materials and a fast magnetic response. Commercial fatty acid-modified iron oxide (IO) nanoparticles were first assembled into spherical clusters through an emulsification/solvent evaporation method. The resulting particles were stabilized with poly(2-dimethylaminoethyl methacrylate)-b-polystyrene (PDMAEMA-b-PS) amphiphilic block copolymers obtained by RAFT, and used as seeds in the emulsion copolymerization of styrene and divinylbenzene (DVB), used as cross-linking agent. The latter revealed to be key in preserving the integrity of the clusters during the emulsion polymerization reaction, and a minimum amount (i.e. 10 wt%) was necessary to obtain stable latexes composed of a core of densely packed IO nanoparticles surrounded by a thin polymer shell. DVB also had a strong influence on the particle morphology as the core-shell morphology of the composite particles could be tuned with either a smooth polymer shell or a raspberry-like surface by adjusting the DVB-to-monomer weight ratio and the feeding conditions. The amphiphilic macroRAFT not only provides colloidal stability to the magnetic latexes, but also offers a versatile platform for the design of composite particles with tailored surface properties by an appropriate choice of the hydrophilic block. Our strategy was thus successfully extended to poly(acrylic acid)-b-polystyrene (PAA-b-PS) copolymers, leading to PAA-stabilized composite particles. Both kinds of IO-encapsulated particles showed superparamagnetic properties (magnetizations at saturation of 35 and 31 emu g-1 for PDMAEMA and PAA systems, respectively), and could thus find interesting applications as magnetic carriers in the biological field due to their thermo- (for PDMAEMA) and pH- (for PDMAEMA and PAA) responsive properties.

Flame Retardant Submicron Particles via Surfactant-Free RAFT Emulsion Polymerization of Styrene Derivatives Containing Phosphorous

The reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of diethyl-(4-vinylbenzyl) phosphate (DEVBP) was performed using PEG-TTC as a macro RAFT agent. PEG-TTC (M_W 2000, 4000) was synthesized by the esterification of poly (ethylene glycol) methyl ether with a carboxylic-terminated RAFT agent, composed a hydrophilic poly (ethylene glycol) (PEG) block and a hydrophobic dodecyl chain. The RAFT emulsion polymerization of DEVBP was well–controlled with a narrow molecular size distribution. Dynamic light scattering and confocal laser scanning microscopy were used to examine the PEG-b-PDVBP submicron particles, and the length of the PEG chain (hydrophilic block) was found to affect the particle size distribution and molecular weight distribution. The submicron particle size increased with increasing degree of polymerization (35, 65, and 130), and precipitation was observed at a high degree of polymerization (DP) using low molecular weight PEG-TTC (DP 130, A3). The flame retardant properties of the PEG-b-PDVBP were evaluated by thermogravimetric analysis (TGA) and micro cone calorimeter (MCC). In the combustion process, the residue of PEG-b-PDEVBP were above 500 °C was observed (A1 ~ B3, 27 ~ 38%), and flame retardant effect of PEG-b-PDEVBP submicron particles/PVA composite were confirmed by increasing range of temperature and decreasing total heat release with increasing contents of PEG-b-PDEVBP. The PEG-b-PDEVBP submicron particles can provide flame retardant properties to aqueous, dispersion and emulsion formed organic/polymer products.

Synthesis of nano-capsules via aqueous emulsion RCMP-PISA and encapsulation

Synthesis of nano-capsules using aqueous RCMP-PISA and encapsulation of rhodamine-B (Rh-B).

Poly(ethylene glycol)-b-poly(vinyl acetate) block copolymer particles with various morphologies via RAFT/MADIX aqueous emulsion PISA

The polymerization-induced self-assembly (PISA) of amphiphilic diblock copolymers of poly(ethylene glycol)-b-poly(vinyl acetate) in water was achieved through macromolecular design via interchange of xanthate (MADIX) polymerization in emulsion.

Polymerization techniques in polymerization-induced self-assembly (PISA)

The development of controlled/“living” polymerization greatly stimulated the prosperity of the fabrication and application of block copolymer nano-objects.

RAFT dispersion polymerisation of lauryl methacrylate in ethanol–water binary mixtures: synthesis of diblock copolymer vesicles with deformable membranes

Diblock copolymer vesicles with deformable membranes are prepared via RAFT dispersion polymerisation of lauryl methacrylate in an 80 : 20 w/w ethanol–water mixture; visible light irradiation allows facile RAFT chain-end removal from these nano-objects.

Cross-linking approaches for block copolymer nano-assemblies via RAFT-mediated polymerization-induced self-assembly

This minireview summarizes the current cross-linking approaches to stabilize block copolymer nano-assemblies obtained via RAFT-mediated PISA process.

Investigating the influence of solvent quality on RAFT-mediated PISA of sulfonate-functional diblock copolymer nanoparticles

Solvent quality has a marked impact on the assembly of sulfonate-functional diblock copolymer nanoparticles prepared by PISA.