Emulsion Polymerization Research Articles

The tribological behavior of thermo‐responsive poly( N ‐isopropylacrylamide) (PNIPAAm)‐based microgels is investigated for use as water‐dispersible lubricant additives. Two types of microgels are synthesized using a surfactant‐free emulsion polymerization method: MG0, consisting of pure PNIPAAm with a volume phase transition temperature (VPTT) of ≈33 °C, and MG16, consisting of PNIPAAm copolymerized with hydrophobic tert ‐butyl acrylamide, exhibiting a lower VPTT of around 23 °C. Swelling and lubrication performance are evaluated at 20 and 40 °C. Both microgels significantly reduce friction and wear compared to water alone. At 20 °C, MG0 remains fully swollen and provides effective wear protection through hydrated microgel lubrication. MG16, being near its VPTT, exhibits partial collapse and slightly higher wear. At 40 °C, MG16 demonstrates improved wear resistance, attributed to enhanced film compaction in the collapsed state. Raman spectroscopy and scanning electron microscopy–energy‐dispersive X‐ray spectroscopy confirm that carbon‐rich tribofilms are formed via tribochemical reactions. MG0 produces more graphitic films, while MG16 generates amorphous carbon structures. These findings highlight the tunability of microgel composition for designing adaptive, water‐based lubricants for temperature‐sensitive applications.

The switchable emulsion drag reducer can effectively avoid the contradiction between the stability of the emulsion and the release of the drag reducer. Notably, the traditional switchable emulsion drag reducer is mainly stabilized by surfactants with a single-tail chain and a single response site, which leads to poor storage stability and low release efficiency. Constructing surfactants with dual tails and multiple response sites offers a promising strategy to improve both stability and release efficiency of the drag reducer. Herein, a surfactant (OLA-BPB) with multiple response sites was synthesized by amidation and the Schiff base reaction. The surface activity of OLA-BPB was sensitively regulated by pH stimulation due to the existence of a tertiary amine group and imine bonds. The emulsion drag reducer prepared by inverse emulsion polymerization of the OLA-BPB-stabilized monomer emulsion exhibited favorable storage stability at 25 °C. The instability behavior of the emulsion drag reducer under pH stimulation was attributed to pH-induced changes in the surface activity of OLA-BPB. Thanks to this specialty, the pH-switchable emulsion drag reducer can be released within a broad pH value window (a range of 2 to 6) and can be completely released within 20 s at pH 3. The drag reduction rate of pH-switchable emulsion drag reducer reached 68.48% at a concentration of 0.05 wt %. The construction of the OLA-BPB offers an alternative option to enhancing the release efficiency of the drag reducer.

Dual-functional probiotic hydrogel with puerarin integration for microbiota-neuroimmune regulation in antibiotic-free periodontitis therapy.

Temperature-responsive polymeric surfactant-based emulsion for dual oil-solid and oil-water separation from oily sludges

Preparation of curcumin@Blumea balsamifera oil-Bletilla striata polysaccharide nanostructured lipid carrier based on "Medicines and Excipients all-in-one" and its scarless wound healing effect.

This study evaluates the technical and economic feasibility of liquid polymer emulsions as substitutes for powder polymers in polymer flooding applications, particularly in space-constrained, low-permeability reservoirs in Austria. Rheological tests determined that target viscosities of 20 mPa·s at 20 °C and a shear rate of 7.94 s−1 were achieved using concentrations of 1200 ppm for liquid polymer 1 (LP1), 2250 ppm for liquid polymer 2 (LP2), and 1200–1400 ppm for powder polymers. Injectivity tests revealed that liquid polymers encountered challenges in 60 mD and 300 mD core plugs, with pressure stabilization not achieved at injection rates of 1–2.5 ft/day. Powder polymers demonstrated stable injectivity, with powder polymer 1 (PP1) showing an optimal performance at 10 ft/day and a low residual resistance factor (RRF). Two-phase core floods using PP1 and powder polymer 2 (PP2) at 1 ft/day yielded incremental oil recovery factors of approximately 5%, with a maximum of 8% observed for higher viscosity slugs. Economic analysis indicated that over a 3-year horizon, liquid polymers are 30% cheaper than powder polymer Option 1 but 100% more expensive than Option 2. Over a 10-year horizon, liquid polymers are 50% more expensive than both powder polymer options. Although liquid polymers offer logistical advantages, they are unsuitable for low-permeability reservoirs. Powdered polymers, particularly PP1, are recommended for pilot implementation due to superior injectivity, mechanical stability, and recovery performance.

Polystyrene (PS) is one of the most widely used synthetic polymers, with annual global production of around 20 million tons. However, its robust C─C backbone renders it highly recalcitrant to (bio)chemical depolymerization, and no sustainable re-/up-cycling method has yet been developed. Here, we establish a proof-of-concept for the efficient depolymerization of PS under mild aqueous conditions, using a laccase-mediator system (LMS) composed of Trametes versicolor laccase, 1-hydroxybenzotriazole (HBT), and ambient oxygen. To overcome substrate accessibility issues, PS is formulated into colloidally stable nanoparticles, promoting interfacial remote biocatalysis. Under such conditions, up to 99.9% decrease in molar mass is achieved from an initial PS of over 2million g mol-1, synthesized by ab initio free-radical emulsion polymerization. This colloidal dispersion strategy is also effective for commercial PS and expanded PS waste processed by post-dispersion in surfactant-containing aqueous media. Mechanistic studies suggest that LMS-mediated depolymerization proceeds via HBT radical diffusion into PS nanoparticles, triggering hydrogen atom transfer (HAT)-based oxidation and β-scissions of PS chains. This approach provides an efficient method for PS depolymerization using aqueous conditions, ambient O2 and a native enzyme without harsh solvents or experimental conditions.

We report the preparation of new synthetic mimics for nitrogen-based polycyclic aromatic hydrocarbon (PANH) cosmic dust particles. From a small library of candidate molecules, we chose to study benzo[h]quinoline (mp = 51 °C). This simple PANH was processed by hot emulsification in the presence of a suitable water-soluble polymeric emulsifier: high shear homogenization at 55 °C converted the initial millimeter-sized drops into much finer molten oil droplets. The mean droplet diameter was readily controlled from 12 to 273 μm by adjusting the shear rate. Subsequent cooling to 20 °C led to crystallization and the formation of polydisperse benzo[h]quinoline microparticles. Interestingly, the nature of the polymeric emulsifier has a significant influence on the final microparticle morphology. Distinctly anisotropic microparticles were obtained using poly(vinyl alcohol), whereas the desired spherical morphology was produced when using Morwet D-425. A melting point diagram constructed for a series of binary mixtures of benzo[h]quinoline and phenanthrene indicated a eutectic composition of 65 mol % benzo[h]quinoline, with a corresponding melting point of just 37 °C. Accordingly, hot emulsification processing was again employed to produce a series of 65:35 benzo[h]quinoline/phenanthrene hybrid microparticles of 19-438 μm diameter. In this case, only the PVA emulsifier produced the desired spherical morphology. These hybrid microparticles were characterized by optical/fluorescence microscopy, laser diffraction, scanning electron microscopy, 1H NMR spectroscopy, and Raman microscopy. Both types of microparticles were fired in turn at aluminum foil or aerogel targets at 0.9 - 1.0 km s-1 using a light gas gun. Under such conditions, the microparticles simply rebounded from aluminum foil, with no signs of fragmentation or melting. In contrast, the 65:35 benzo[h]quinoline/phenanthrene microparticles underwent complete ablation during their aerogel capture. These new PANH synthetic mimics combined with such high-energy impact data should inform the design and calibration of cosmic dust detectors for the next generation of interplanetary unmanned spacecraft.

ABSTRACT Tri‐layered ASA core–shell toughening particles with controlled grafting ratios were synthesized to simultaneously improve the mechanical properties of poly(styrene‐co‐acrylonitrile) (SAN). Poly(butyl acrylate) (PBA) cores with different grafting agent distributions were synthesized via semicontinuous emulsion polymerization. ASA particles were then prepared by the grafting emulsion polymerization at different conditions. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) revealed particle sizes of 395–471 nm, uniform dispersion, and stable morphology. Samples with a moderate grafting ratio (11.5%) exhibited the best property balance, with 11.5 kJ/m 2 impact strength, 15% elongation at break, and a Vicat softening point of 101.2°C. At 0.15% t‐dodecyl mercaptan (TDDM) loading, rubber cores achieved optimal flexibility and stability, yielding the highest toughness. Incorporating 10% methyl methacrylate (MMA) increased the grafting ratio to 15.2%, improving whiteness (66%), brightness (91.3%), gloss (83.6%), and tensile strength (54 MPa); the toughening ability of ASA particles was limited when the grafting ratio reached certain levels. These findings demonstrate that controlling the tri‐layer core–shell architecture, TDDM concentration, and MMA fraction allows for simultaneous optimization of toughness, thermal stability, and surface properties in ASA resins.

A series of rapeseed protein isolate (RPI) composite emulsions for use as wood adhesives were successfully prepared via emulsion polymerization. The chemical composition, properties, and bond strength of the composites were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), water resistance residual rate tests, and shear strength measurements. The active group of RPI can be intramolecular or intermolecular crosslinked with methacryloxypropyl trimethoxysilane (MPTS) and methyl acrylate. FT-IR analysis shows that there are N–Si bonds and hydrogen bonds in the composite emulsion. The glass transition temperature of rapeseed protein modified by methacryloxypropyl trimethoxysilane and methyl acrylate changed. The shear strength, thermal stability and hydrophobicity of the modified RPI were all improved.

Solar-thermal distillation offers immense and hitherto untapped potential for energy-efficient, sustainable freshwater production. However, critical limitations in material and system design continue to hinder water-evaporation rate (Rw) and specific water productivity (SWP), posing significant roadblocks for scalable and stable solar desalination. An ultrathin, porosity-tuned high internal phase emulsion polymer (polyHIPE, PH) scaffold is integrated with nanostructured hard-carbon florets (NCF) as a black-body absorber to create the thinnest interfacial evaporator, delivering best-in-class solar-thermal energy conversion (η-STC = 84%), rapid Rw (6.5 kg m-2 h-1), and efficient SWP of 18 L m-2 day-1 from seawater. The Janus-faced NCF@PH confines solar-thermal energy at the interface, which also promotes extensively convex water menisci, to deliver high Rw. The continuously interconnected 3D capillary channels within NCF@PH ensure continuous water transport, while their hydrophobic surfaces prevent salt deposition for robust long-term seawater distillation with high salt rejection (>90%). Furthermore, a system-level prototype termed SunSpring (SS) works to decouple the light-admitting, water-evaporation, and water-condensation steps to produce environmental protection agency (EPA)-standard freshwater (<10ppm salinity) from highly saline seawater (35 000ppm) for over ≈225h of real-time continuous usage. It is also estimated that SS has the lowest energy (<3 W L-1) and CO2 (≈3 g L-1) footprints, representing a paradigm shift in the water-energy nexus.

Driven by surging demand in battery technologies, the global production of polyvinylidene fluoride (PVDF) urgently requires scalable and efficient synthesis methods. Current batch processes are constrained by mass and heat transfer limitations, causing scalability and efficiency bottlenecks. Here, we introduce a novel continuous flow reactor for the fluorosurfactant-free emulsion polymerization of VDF, utilizing a dense tubular membrane made of Teflon AF-2400 to establish a stable phase boundary. This significantly improves mass and heat transfer, reduces energy use, and enables high space-time yields exceeding 190 kg m-3 h-1 at just 15 bar gas pressure. Our approach offers substantial advantages in industrial scalability, consistency in polymer quality, and potential adaptability to other gas-liquid-solid polymerization systems.

We report for the first time a method for forming polyacrylate nanoparticles using N-acryloylciprofloxacin as a sole monomer for emulsion polymerization. The procedure involves a free radical-induced emulsion polymerization of N-acryloylciprofloxacin monomer to produce a stable aqueous emulsion comprising uniformly sized polyacrylate nanoparticles. Dynamic light scattering analysis of the emulsions showed a single population of nanoparticles having an average diameter of 970 nm and average surface charge of −63 mV, indicative of the high stability of the emulsion and significantly enhance lipophilicity of the polymeric matrix of the nanoparticle. Antibacterial testing of the emulsions against the Gram-positive microbe Staphylococcus aureus and the Gram-negative Escherichia coli found in vitro activities identical to those of the reference clinical agent, ciprofloxacin. Assays against human colorectal carcinoma cells and human embryonic kidney cells showed essentially no cytotoxicity. This is the first study on the synthesis of aqueous nanoparticle emulsions assembled solely from a single monomer derived from the antibiotic agent.

Fluazinam is a broad-spectrum fungicide and acaricide, but its field performance is limited by temperature sensitivity and phytotoxicity. To overcome these challenges, a thermoresponsive nano-formulation (Flu@TRNP) was developed by encapsulating fluazinam in a poly(N-isopropylacrylamide-styrene) copolymer matrix via emulsion polymerization. The microcapsules exhibited uniform spherical morphology (mean diameter: 3.4 μm), high encapsulation efficiency (75.3%), and temperature-dependent release governed by the polymer lower critical solution temperature (~32 °C). Below this temperature, release was almost complete, whereas above it, polymer shrinkage slowed diffusion and enabled sustained release. Flu@TRNP displayed significantly lower contact angles on leaf surfaces compared with commercial fluazinam, indicating improved wettability. Bioassays showed enhanced acaricidal activity against Tetranychus urticae, with median lethal concentration (LC50) values reduced by up to 25% at 35 °C. Antifungal tests against Phytophthora infestans confirmed greater inhibition at 20 °C. Field trials demonstrated comparable or superior disease control efficacy at reduced or standard doses. Pot experiments under heat stress (40 °C) indicated lower phytotoxicity on cowpea and potato compared with the commercial formulation. These results demonstrate that the thermoresponsive microcapsule formulation improves bioefficacy and crop safety while reducing the risk of phytotoxicity under fluctuating environmental conditions. © 2025 Society of Chemical Industry.

Hexavalent chromium (Cr(VI)) contamination in water poses severe environmental and health risks, necessitating efficient and sustainable removal technologies. A water-based polyacrylic resin was synthesized via inverse emulsion polymerization using methyl methacrylate, acrylic acid, and maleic anhydride, thereby avoiding the use of organic solvents. Under optimal conditions (0.8 g dosage, pH 2, 318 K, 12 h), the resin achieves 98.73% Cr(VI) removal from 1 mg/L wastewater, following the pseudo-second-order kinetic model (R2 = 0.9927). Furthermore, the adsorption is well-fitted to the Langmuir model (R2 = 0.9911), yielding a calculated maximum adsorption capacity of 142.86 mg/g. FTIR analysis confirms chemisorption via Cr–O bond formation as the key mechanism. Thermodynamic analysis supports this chemisorption dominance, revealing an exothermic process (ΔH = 138.47 kJ/mol) with high spontaneity (ΔG < 0). Characterization via SEM/XRD shows the resin’s 3D porous structure maintains integrity post-adsorption. Significantly, acid–base elution enables high regeneration efficiency (> 93%) over 5 cycles without secondary pollution. These findings highlight the promising potential of the water-based polyacrylic resin as a macromolecular adsorbent for the efficient removal of Cr(VI) ions from wastewater, offering a viable solution for wastewater treatment.

ABSTRACTIndole and thiazole derivatives have garnered significant attention due to their potent antitumor activities. Encapsulation of such derivatives into polymeric nanoparticles offers several advantages, including improved molecular stability and targeted delivery to tumor sites, thereby enhancing their antineoplastic potential. This study aimed to encapsulate a novel methoxyl‐substituted indole‐thiazole derivative (CS08) into polymeric nanoparticles and evaluate its antiproliferative activity against metastatic breast cancer cells (MDA‐MB‐231). Nanoparticles were prepared using the anionic emulsion polymerization (AEP) technique and coated with either dextran or fucoidan as biocompatible polysaccharides. The resulting nanoparticles were characterized for their physicochemical properties, including particle size, zeta potential, morphology via scanning electron microscopy (SEM), and structural composition using infrared (IR) spectroscopy. Dextran‐coated nanoparticles exhibited an average diameter of 232.7 ± 0.55 nm and a zeta potential of +15.6 ± 0.45 mV, whereas fucoidan‐coated nanoparticles had a larger size of 389.2 ± 19.97 nm and a more negative zeta potential of −63.9 ± 1.13 mV. Importantly, both nanoparticle formulations were noncytotoxic to macrophage cells. Moreover, CS08‐loaded nanoparticles demonstrated enhanced antiproliferative activity against MDA‐MB‐231 cells, surpassing the efficacy of doxorubicin in vitro. These findings highlight the potential of CS08‐loaded polymeric nanoparticles as promising candidates for metastatic breast cancer therapy.

Polymer particles are widely used in biomedical applications as a latex, in which antifouling properties are essential for minimizing nonspecific biomolecular adsorption. In this study, polymer particles grafted with zwitterionic polymer brushes at controlled densities were prepared to suppress nonspecific adsorption. Particles bearing atom transfer radical polymerization (ATRP) initiators were synthesized via emulsifier-free emulsion polymerization via a mixture of ATRP inimer and dummy inimer. The surface-accessible ATRP initiator density, quantified by fluorescence labeling, was tunable by varying the inimer feed ratio. Poly(2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate) (PMPC) brushes were grown from the particle surfaces and free ATRP initiator in solution via surface-initiated activator generated by electron transfer ATRP (SI-AGET ATRP) in a methanol/water mixture using tris[2-(N,N-dimethylamino)ethyl]amine as a ligand. The free polymer showed a linear increase in the number-average molecular weight with conversion and relatively low dispersity (Mw/Mn = 1.25-1.30), confirming well-controlled polymerization. The grafting density of the resulting brushes on the particles was correlated with the surface-accessible ATRP initiator density. The antifouling performance, evaluated by quantifying bovine serum albumin adsorption, indicated that the particles coated with high-density PMPC brushes (0.11 chains/nm2) exhibited significantly reduced nonspecific adsorption compared with those coated with lower-density brushes. Both controlled SI-AGET ATRP of MPC and high-grafting density were essential for producing polymer particle surfaces with significantly effective antifouling properties. This approach enables the facile fabrication of antifouling polymer particles for highly sensitive diagnostic methods and precise bioseparation.

Purpose The purpose of this paper was to develop an eco-friendly water-based ink with excellent performance via using polyacrylate emulsion prepared by semi-continuous seed. During the emulsion polymerization process, green and renewable non-ionic surfactant alkyl polyglycoside (APG) combined with sodium dodecyl sulfate (SDS) was used as the emulsifier. Design/methodology/approach The as-prepared emulsion was characterized by Fourier-transform infrared spectroscopy and an atomic force microscope. The synthesis conditions of polyacrylate latex were optimized by the L9 (34) orthogonal test. Using the resultant polyacrylate latex as the binder, a new water-based ink was achieved and its printing performance was compared with that of the ink prepared by the OP-10/SDS emulsifying system. Findings Optimum synthetic conditions (including the hard-to-soft monomer ratio and the dosage of functional monomer, complex emulsifier and initiator) were 5:4, 2%, 6% and 0.4%, respectively. The results showed that the initial dryness of the water-based ink prepared with the proposed green emulsifier was almost the same as that of the traditional emulsifier (OP-10/SDS). And both of the inks exhibited good adhesion properties on polyethylene terephthalate, polyamide, polyvinyl chloride and polyethylene films, especially on polyethylene substrates, that reached 100%. Originality/value Polyacrylate emulsion synthesized with the renewable emulsifier was used as the binder for water-based ink. The obtained ink exhibited excellent properties and potential applications in the field of packaging and printing. In a word, an excellent eco-friendly water-based ink with two main properties – adhesion and dryness being improved was developed by using renewable emulsifier.

Spatially Resolved Reaction Calorimetry and Fouling Monitoring in a Continuous Tubular Emulsion Polymerization Reactor

19F magnetic resonance imaging (19F MRI) is an emerging non-invasive imaging modality with a high signal-to-noise ratio (SNR) and negligible background interference from biological tissues. However, the hydrophobic nature of fluorine atoms limits both 19F signal intensity and in vivo applicability. Therefore, developing fluorinated MRI contrast agents that combine high fluorine content with good hydrophilicity is essential for advancing in vivo 19F MRI. In this study, a fluorine-containing nanogel (FNG) is synthesized via emulsion polymerization and de-protection using trifluoroethyl methacrylate (TFMA) and tert-butyl acrylate (t-BA). The FNG is then loaded with the near-infrared photosensitizer IR780 to obtain a multifunctional imaging probe (IFNG) capable of dual-modal 19F MR and fluorescence (FL) imaging-guided photodynamic therapy (PDT). The resulting IFNG exhibited a T2 relaxation time of 46.32ms, confirming its excellent MRI performance in vitro. In the tumor microenvironment, IFNG undergoes glutathione (GSH)-responsive decrosslinking, which exposes the encapsulated IR780. This process enhances fluorescence signal and promotes reactive oxygen species (ROS) generation under near-infrared light, thereby triggering effective PDT. Overall, these findings demonstrate IFNG as a promising nanoplatform that integrates dual-modal 19F MR/FL imaging with GSH-activated photodynamic therapy, offering great potential for precise tumor localization and image-guided cancer treatment.