Pickering Emulsion Polymerization Research Articles

Exfoliated MXene nanosheet by double layer forces for preparing magnetic adsorbents of toxic metal ions and recycling with hyperthermic effect

The conventional etching method for exfoliating MXene using hydrofluoric acid solution is time-consuming and inefficient in productivity. A double layer force is generated through polarization among the heterogeneous layers of MXene due to their different dielectric properties. The exfoliated MXene by the polarization method in an acidic solution was employed to synthesize magnetic MXene (MXFe) with Fe3O4 nanoparticles. MXFe was coated on polyacrylonitrile microspheres (PANs) as precursors (PAN@MXFe) by Pickering emulsion polymerization. The core@shell polyvinyltetrazole@MXFe (PVT@MXFe) was obtained as the adsorbent after subsequent cyano-tetrazole conversion of PAN@MFs for the removal of toxic metal ions. The maximum adsorption capacities of Hg(II) on the MXFe and PVT@MXFe coating 2 wt% of MXFe were 579 and 324 mg/g, respectively, indicating the high use efficiency of MXFe. At 8.5 kHz of high frequency, hyperthermia occurs on the PVT@MXFe, facilitating the desorption of the toxic metal ions from the adsorbents. Compared with reuse using an acidic solution, the PVT@MXFe can be reused repeatedly 10 times without obvious damage under the AMF. Our proposed polarization exfoliation method not only provides a novel methodology to exfoliate MXene but also develops an ideal adsorbent for universal adsorption, simple separation, stable regeneration, and low secondary pollution.

Interfacing Langmuir-Blodgett and Pickering Emulsions for the Synthesis of 2D Nanostructured Films: Applications in Copper Ion Adsorption.

This research focuses on developing a 2D thin film comprising a monolayer of silica nanoparticles functionalized with polyethyleneimine (PEI), achieved through a novel integration of Langmuir-Blodgett (L-B) and Pickering emulsion techniques. The primary aim was to create a nanostructured film that exhibits dual functionality: iridescence and efficient metal ion adsorption, specifically Cu(II) ions. The methodology combined L-B and Pickering emulsion polymerization to assemble and stabilize a nanoparticle monolayer at an oil/water interface, which was then polymerized under UV radiation to form an asymmetrically structured film. The results demonstrate that the film possesses a high adsorption efficiency for Cu(II) ions, with the enhanced mechanical durability provided by a reinforcing layer of polyvinyl alcohol/glycerol. The advantage of combining L-B and Pickering emulsion technology is the ability to generate 2D films from functional nanoparticle monolayers that are sufficiently sturdy to be deployed in applications. The 2D film's practical applications in environmental remediation were confirmed through its ability to adsorb and recover Cu(II) ions from aqueous solutions effectively. We thus demonstrate the film's potential as a versatile tool in water treatment applications owing to its combined photonic and adsorptive properties. This work paves the way for future research on the use of nanoengineered films in environmental and possibly photonic applications focusing on enhancing the film's structural robustness and exploring its broader applicability to other pollutants and metal ions.

Self‐healing waterborne fluorinated polyurethane‐acrylate based on photoreversible reaction and hydrogen bonds

AbstractThe development of self‐healing materials is an effective strategy to improve the service life of polymer materials. In this study, self‐healing waterborne fluorinated polyurethane‐acrylate (WFPUA) containing UV‐responsive coumarin groups was prepared by Pickering emulsion polymerization using modified cellulose nanocrystal as a stabilizer. The effect of double bond‐terminated waterborne polyurethane content on emulsion polymerization and latex film properties was mainly studied. Due to the dynamic reversibility of the coumarin groups and the synergistic effect of hydrogen bonds, the optimized sample (WFPUA‐30) had excellent mechanical properties and self‐healing properties. The tensile strength was 5.24 MPa and the elongation at break was 267%. The self‐healing efficiency of tensile strength and elongation at break after 6 h of repair was 86.52% and 93.20%, respectively. In addition, due to the presence of fluorine‐containing groups, the water and oil contact angles of the latex film could reach 101.7° and 82.1°, respectively. This work broadens the way for the manufacture of self‐healing and multifunctional waterborne polyurethane‐acrylates. © 2024 Society of Industrial Chemistry.

Cellulose nanocrystals/fluorinated polyacrylate with mechanical tunability, water-oil resistance and self-healing capability via light actuated reversible associations

Traditional fluorinated polyacrylate has been extensively applied in various fields, which is favored by many researchers. However, the polymer usually can lose usefulness when it is damaged. Endowing the polymer with self-healing capability provides a potential solution to address the conflict. Herein, a series of photo actuated self-healing fluorinated polyacrylate based on coumarin groups was synthesized by reversible addition-fragmentation chain transfer (RAFT)-assisted Pickering emulsion polymerization using the modified cellulose nanocrystals as the stabilizer, n-butyl acrylate (BA) as the soft monomer, and methyl methacrylate (MMA) as the hard monomer. The influences of the dosage of 7-(4-vinylbenzyloxy)−4-methylcoumarin) (VBMC) and the mass ratio of BA to MMA on the emulsion polymerization and latex film properties were studied. The results showed that the latex particle size and its distribution decreased and then increased as the VBMC dosage and the mass ratio of BA to MMA increased. The latex film exhibited not only high ultimate tensile stress (6.36 MPa) and large stretchability (575.71%) but also a certain anti-fatigue characteristic. The water and oil contact angles of latex film could reach 118.5° and 101.7°, respectively. Besides, the latex film could achieve efficient self-healing capability due to the mobility of polymer chains associated with low glass transition temperature (Tg) and the reversible [2+2] cleavage/dimerization reaction of the coumarin groups upon ultraviolet (UV) irradiation of 254 nm and 365 nm. The work offers a substantial reference for developing different light actuated self-healing polymers with great prospects and promising futures.

Preparation of light‐responsive block copolymer modified cellulose nanocrystal@polydopamine particle and its application in fluorinated polyacrylate film

AbstractLight‐responsive cellulose nanocrystal@polydopamine (CNC@PDA) modified fluorinated polyacrylate was synthesized by Pickering emulsion polymerization with light‐responsive block copolymer modified CNC@PDA as stabilizer. The epoxy groups in poly(acrylic acid‐co‐acrylamide)‐b‐poly(glycidyl methacrylate)‐b‐poly(hexafluorobutyl acrylate‐co‐coumarin) amphiphilic triblock copolymer reacted with the hydroxyl and amino groups on the surface of CNC@PDA to form the modified CNC@PDA. The successful preparation of modified CNC@PDA was confirmed by means of FT‐IR, XRD, TG, UV–Vis, surface tension measurement, and X‐ray photoelectron spectroscopy (XPS) techniques. The results showed that the modified CNC@PDA had light‐responsive and amphiphilic properties, and could be used as stabilizer to form stable Pickering emulsion. And the influence of modified CNC@PDA dosage on emulsion polymerization and film performance was systematically studied. The latex particle size decreased initially with increasing modified CNC@PDA dosage, from 0.6 to 1.0 wt%, and then increased. The mechanical, self‐healing, and water–oil repellent properties of film were enhanced initially with increasing modified CNC@PDA dosage, from 0.6 to 1.0 wt%, and then declined. Atomic force microscope confirmed that the latex film had a rough surface. Moreover, the latex film comprising 1.0 wt% modified CNC@PDA presented not only high tensile strength (4.92 MPa), large elongation at break (657.70%), and superior oil/water repellency but also excellent self‐healing property.

Temperature-responsive microcapsule hydrogel fabricated by pickering emulsion polymerization for pheromones application

Insect pheromone is a natural effective biological pesticide. To improve the utilization efficiency of pheromone pesticides and reduce labor costs, a sustained and controlled release preparation coordinating with the circadian rhythm of insects has been proposed by our previous report. However, that preparation has some deficiencies, such as the loading capacity of pheromone and sustained time. In order to overcome the existent shortcomings, a temperature-responsive release microcapsule hydrogel loaded with myrcene (as a pheromone model) was fabricated by Pickering emulsion polymerization using modified SiO2 nanoparticles as a stabilizer of microcapsule wall, octadecane and Poly(N-isopropylacrylamide) (PNIPAM) separately as temperature responders of microcapsule core and wall in the present study. The morphological structure and thermal performance of the microcapsule hydrogel were characterized. The release behaviors of myrcene at different environmental temperatures and alternating temperature cycles were also tested. The results indicated that myrcene was successfully loaded in the Myrcene/Octadecane@SiO2-PNIPAM (MOSP) microcapsule hydrogel with encapsulation efficiency and loading capacity of 80.3 % and 13.3 %, respectively. The results of the myrcene release under simulated diurnal temperature cycles revealed that the cumulative release amount was only about 43 % during 15 cycles and release rates respectively were about 0.79 μg/h at 35 °C and 0.058 μg/h at 25 °C, which demonstrated the persistent temperature sensitivity and good temperature rhythm remained after 15 cycles. These results suggested that the MOSP microcapsule hydrogel had a good controlled release effect on myrcene and could adapt well to the circadian rhythm activity of some insects. Therefore, this study provided a promising strategy to improve the utilization efficiency of pheromones through the combination of octadecane and PNIPAM as pheromones release controllers.

A deeper insight into the evaluation of water-in-oil amicroemulsion templated samarium sulfide nanospheres: exploring its role in pickering emulsion formulation for photocatalytic dye degradation and synthesis of PANI@Sm2S3 nanocomposites.

This study examines the effectiveness of W/O microemulsion-mediated Sm2S3 nanospheres in pickering emulsion-based crystal violet (CV) dye degradation and PANI@Sm2S3 nanocomposite synthesis. The evaluation of nanospheres inside the core of reverse micelles was performed through DLS, TEM and FESEM analyses. The formation of nanospheres involve two phases: a nucleation phase (5-30 min) and growth phase (30-120 min). Through in situ hydrophobization of negatively charged (with a zeta value of -4.47 mV at neutral pH) Sm2S3 nanoparticles (0.1 wt%) with a suitable amount of a cationic CTAB surfactant, a stable O/W pickering emulsion was developed. 0.1 wt% Sm2S3in situ hydrophobized with 2.7 mM CTAB offered a stable pickering emulsion with a diameter of 23 μm after 1 day of storage. This pickering emulsion improves the local concentration of CV by efficiently encapsulating dye molecules inside the core of emulsion droplets. Therefore, dye molecules get numerous opportunities to interact with the Sm2S3 photocatalyst and efficiently degrade. The pickering emulsion stabilised by 0.1 wt% of Sm2S3 nanoparticles in situ hydrophobized with 2.7 mM of CTAB results in almost 100% degradation. Moreover, using only solid Sm2S3 (having wt% of 0.025 or 0.075) as a pickering stabiliser, new PANI@Sm2S3 spherical nanocomposites were synthesised via pickering emulsion polymerization. The formation of PANI@Sm2S3 composites was identified via UV-vis, IR, and 1H-NMR investigations. The analysis of FESEM images showed that the amount of nanoparticles used in the dispersion (for 0.025 wt%, 35 nm and 0.075 wt%, 29 nm) strongly influences the size and shape of the composites.

Large–size porous spherical 3D covalent organic framework for preconcentration of bisphenol F in water samples and orange juice

Large–size spherical sorbents with particle size of 10–50 μm are widely applied in separation fields, however it is still a great challenge to synthesize such large–size spherical covalent organic framework (COF). In this work, a type of large–size porous 3D COF was size–controablly synthesized via a two–step strategy, in which a large–size porous 3D spherical polymer was prepared first through a Pickering emulsion polymerization using nano silica as the stabilizer, and subsequently it was converted into porous spherical 3D COF by a solvothermal method. The as–prepared porous spherical COF (COF–320 as a model) showed size–controllable uniform spherical morphology within 15–45 μm, large specific surface area, fine crystalline structure, and good chemical stability. When used as the sorbent for dispersive solid–phase extraction (d–SPE) of bisphenol F (BPF), the porous spherical COF–320 (15 μm) displayed high adsorption capacity (Qmax = 335.6 mg/g), high enrichment factor (80 folds), and good reusability (at least five cycles). By coupling the d–SPE method to HPLC, a new analytical approach was developed and successfully applied to the determination of trace BPF in two water samples, an orange juice and a standard sample with recoveries of 96.0–102.2 % (RSD = 1.1–1.5 %), 95.7–97.4 % (RSD = 1.4–4.4 %) and 98.7 % (RSD = 2.3 %), respectively. The limit of detection (S/N = 3) and limit of quantification (S/N = 10) were 0.1 and 0.3 ng/mL, respectively. The new synthesis strategy opens a viable way to prepare large–size porous spherical COFs, and the developed analytical method can be potentially applied to sensitively detect the trace BPF in water samples and beverages.

Preparation, stretch‐induced crystallization and thermo‐oxidative aging behavior of poly (lactic acid)/saponite grafted polystyrene nanocomposites films

AbstractIn this work, modified saponite (SAP‐g‐PS) was prepared by Pickering emulsion polymerization, and the optimum synthesis conditions of SAP‐g‐PS were investigated. Furthermore, SAP‐g‐PS was used as a reinforcing filler for poly (lactic acid) (PLA) and the mechanical properties results revealed that the elongation at break increased by 81.51% compared to pure PLA when SAP‐g‐PS was added up to 0.5 wt%. Scanning electron microscopy analysis showed that the fracture of PLA based nanocomposite films was ductile. The thermal analysis results showed that the maximum thermal decomposition temperature was increased from 352.19°C (PLA0, pure PLA film) to 361.63°C (PLA3, 0.5 wt% SAP‐g‐PS), and the crystallinity was increased from 18.2% (PLA0) to 31.3% (PLA3) at the traction ratio of 14. The stretch‐induced crystallization behavior of PLA based nanocomposites films was investigated under the conditions of the optimum blow molding process, and it was found that the elongation at break of PLA0 films increased from 25.8% to 37.4% and that of PLA3 was increased from 81.4% to 135.5% with the increase of the traction ratio, the crystallinity of both films showed an increasing trend, which indicated that the presence of the tensile flow field improved the orientation of the PLA, and increased its crystallization and mechanical properties. The thermo‐oxidative aging kinetics of PLA based nanocomposites films with different additions of SAP‐g‐PS were investigated by thermo‐oxidative aging experiments, and the lifetime of the films were predicted by the Arrhenius equation, which showed that the addition of SAP‐g‐PS effectively improved the lifetime of PLA based nanocomposites films.

Antibacterial and angiogenic potential of iron oxide nanoparticles-stabilized acrylate-based scaffolds for bone tissue engineering applications

Pickering emulsion polymerization, stabilized by inorganic nanoparticles such as iron oxide nanoparticles (IONPs), can be used to fabricate scaffolds with the desired porosity and pore size. These nanoparticles create stable emulsions that can be processed under harsh polymerization conditions. IONPs, apart from serving as an emulsifier, impart beneficial bioactivities such as antibacterial and pro-angiogenic activity. Here, we coated IONPs with three different weights of oleic acid (5.0 g, 7.5 g, and 10.0 g) to synthesize oleic acid-IONPs (OA-IONPs) that possess the desired hydrophobicity (contact angle > 100°). Next, glycidyl methacrylate and trimethylolpropane triacrylate were polymerized using the Pickering emulsion polymerization technique stabilized by the OA-IONPs. The physicochemical properties of the resulting porous scaffolds were thoroughly characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), and a universal testing machine (UTM). The SEM images confirmed the formation of a porous scaffold. The IONPs content, measured using inductively coupled plasma mass spectrometry (ICP-MS), was in the range of 22–26 µg/mg of the scaffold. The mechanical strengths of the scaffolds were in the range of cancellous bone. The degradation profile of the scaffolds varied between 29% and 41% degradation over 30 days. In vitro cytotoxicity studies conducted using the fibroblast (L929) and osteosarcoma (MG-63) cell lines proved that these scaffolds were non-toxic. SEM images showed that the MG-63 cells adhered firmly to the scaffolds and exhibited a well-spread morphology. The antibacterial activity was confirmed by percentage inhibition studies, SEM analysis of bacterial membrane distortion, and reactive oxygen species (ROS) generation in the bacteria. Chick chorioallantoic membrane assay showed that the total vessel length and branch points were significantly increased in the presence of the scaffolds. These results confirm the pro-angiogenic potential of the fabricated scaffolds. The physicochemical, mechanical, and biological properties of the material suggest that the developed scaffolds would be suitable for bone tissue engineering applications.

Facile fabrication of hollow molecularly imprinted polymer microspheres via pickering emulsion polymerization stabilized with TiO2 nanoparticles

The polymer microspheres with hollow structure are of technological importance in the removal of pollutants because of the large specific surface area and low mass transfer resistance. In this work, we employ the Pickering emulsion polymerization stabilized with TiO2 nanoparticles to build the molecularly imprinted polymers microspheres with hollow structure (H-MIPs) for the precise recognition of dibutyl phthalate (DBP), which would influence the biological reproductive system and endocrine system as a typical endocrine disrupting compound. The polymerization induced phase separation occurring within Pickering emulsion droplets plays a significant role in the formation of hollow structure. The morphology and structure of H-MIPs were observed via optical microscope and field emission scanning electron microscope, respectively. The results indicate that H-MIPs microspheres are of irregular spherical form with sunken surface and perfect hollow structure. The forming process of the hollow structure was analyzed in detail. Besides, the chemical structure and thermal stability of H-MIPs and H-NIPs were characterized by fourier transform infrared spectroscopy and thermal gravimetric analysis, respectively. The binding performance of H-MIPs and H-NIPs was investigated through a series of binding experiments, which consist of the binding kinetics, binding isotherm, selective test and reusability experiment. The results show that H-MIPs microspheres exhibit remarkable binding kinetics towards DBP, and the saturated adsorption time is not more than 30 min. Apart from the fast binding rate, H-MIPs also show considerable binding amount, accurate binding selectivity and good regenerability. The imprinting factor could reach to 2.56, and the binding amount towards DBP remains at a relatively high level within 3 cycles. The prepared H-MIPs microspheres have broad application prospects in environmental and analytical field involved DBP, and the study also offers an alternative method for the facile building of H-MIPs microspheres.

Pickering Emulsion Polymerization Technology─Toward Nanostructured Materials for Applications in Metal Ion Extractions from Wastewaters

Pickering Emulsion Polymerization Technology─Toward Nanostructured Materials for Applications in Metal Ion Extractions from Wastewaters

Light-activated cellulose nanocrystals/fluorinated polyacrylate-based waterborne coating: Facile preparation, mechanical and self-healing behavior

The development of environmental-friendly self-healing nanocomposites has attracted much attention. In this paper, the light-activated cellulose nanocrystals/ fluorinated polyacrylate-based waterborne coating based on the reversible cycloaddition reaction of the coumarin groups was prepared via Pickering emulsion polymerization. The cellulose nanocrystals (CNCs) modified by the PDMAEMA-b-PGMA-b-P(HFBA-co-VBMC) copolymer were studied via FT-IR and TGA. In addition, the dispersity and interface behavior of CNCs before and after modification were investigated by DLS and interfacial tension measurements. Afterwards, we focused on the influence of modified CNCs, PDMAEMA-g-CNC-g- P(HFBA-co-VBMC) (MCNC) dosage on the Pickering emulsion, emulsion polymerization and properties of latex film. The droplet diameter of Pickering emulsion gradually reduced with the increase of MCNC dosage. The MCNC dosage for the minimum average size and optimum stability of latex particles was 1.0 wt%. Moreover, the latex film comprising 1.0 wt% MCNC presented not only high tensile stress (6.0 MPa), large elongation at break (567.70 %) and superior oil/water repellency but also excellent self-healing properties. The outstanding self-healing capability of latex film was attributed to the reversible light-activated dimerization of coumarin groups. The preparation method for the advanced performance waterborne cellulose nanocrystals/fluorinated polyacrylate will provide valuable guidance for the development of versatile materials.

Advances in Organic-Inorganic Hybrid Latex Particles via In Situ Emulsion Polymerization.

Hybrid latex particles combine the unique properties of inorganic nano/micro particles with the inherent properties of polymers, exhibiting tremendous potential for a variety of applications. Recent years have witnessed an increased interest in the design and preparation of hybrid latex particles with well-defined size, structure and morphology. Due to its simplicity, versatility and environmental friendliness, the in situ (Pickering) emulsion polymerization has been demonstrated to be a powerful approach for the large-scale preparation of hybrid latex particles. In this review, the strategies and applications of in situ (Pickering) emulsion polymerization for the preparation of hybrid latex particles are systematically summarized. A particular focus is placed on the strategies for the preparation of hybrid latex particles with enhanced properties and well-defined core-shell, yolk-shell, multinuclear, raspberry-like, dumbbell-shaped, multipod-like or armored morphologies. We hope that the considerable advances, examples and principles presented in this review can motivate future contributions to provide a deeper understanding of current preparation technologies, develop new processes, and enable further exploitation of hybrid latex particles with outstanding characteristics and properties.

Cellulose nanocrystal/polymer nanocomposite latex via surfactant-free emulsion polymerization

Polar cellulose nanocrystals (CNCs) are difficult to disperse well in hydrophobic polymer matrices, and usually surfactants or expensive and time-consuming functionalization of the reinforcement or matrix have been attempted to improve dispersion. Here, we report a new, facile method to prepare CNC/polymer nanocomposite latices directly via surfactant-free emulsion polymerization of vinyl monomers and CNCs initiated by a cationic, water-soluble, free-radical initiator. The distribution of CNCs in the latex particles can be tailored through controlling the reaction procedures, namely, whether the monomers are added before or after preheating the CNCs with the initiator and has been confirmed by scanning electron microscopy (SEM) and scanning transmission X-ray microscopy (STXM) studies. CNCs distribute inside the latex particles if the monomers are added after the preheating step, and owing to the more even distribution of CNCs, such nanocomposite latices exhibit better mechanical properties than those prepared without preheating or via physically mixing CNCs with emulsions polymerized using conventional surfactant system. A latex particle formation mechanism is proposed based on these phenomena and polymerization kinetics studied in this work. Unlike typical CNC-based Pickering emulsion polymerization, our process can be operated without the need for intense mechanical shearing and provide an industrially scalable approach to prepare stable CNC/polymer nanocomposite latices that can be melt processed or used directly in a variety of applications, such as paints and coatings, adhesives, or cosmetics.

Fabrication of poly (styrene-acrylate)/silver nanoparticle-graphene oxide composite antibacterial by in situ Pickering emulsion polymerization

Graphene oxide (GO) nanosheets decorated with silver nanoparticles (AgNPs) were easily synthesized by chemical reduction, and the prepared nanocomposite was then used as a stabilizer in the Pickering emulsion polymerization of poly (styrene-acrylate) to prepare PSA/AgNPs-GO composites. The AgNPs-GO nanocomposites were fully characterized by TEM, FTIR, Raman, SEM and XPS, which demonstrated that about 5–30 nm AgNPs with spherical, octahedral and cubic structures were decorated on the surface of wrinkled GO nanosheets. TEM photos and EDS spectrum of composites showed that the transparent GO nanosheets decorated with AgNPs were covered on the surface of PSA latexes and the AgNPs were uniformly dispersed on the surface of the PSA latexes without aggregation. The average diameter of composite latexes was obviously bigger than that of PSA latexes. However, the role of surfactant and the properties of hydrophilicity decreased the average diameter and WCA of composites while increasing the additions of AgNPs-GO nanocomposites. AFM images disclosed that wrinkled GO nanosheets decorated with AgNPs dispersed on the surface of composite films. XPS data proved clearly that silver was present only in metallic form and migration occurred during film-formation. TGA curves confirmed the composite film displayed better thermal stability than that of PSA. The results of antibacterial activity revealed that composite films had exhibited antibacterial properties against both E. coli and S. aureus, and the latter showed better antibacterial efficacy than the former. The nano-silver polyacrylate coatings with antibacterial activity explored in current work have wide application in the fields of wood coatings, leather finishing, and so on.

A Novel Sulfonamide, Molecularly Imprinted, Upconversion Fluorescence Probe Prepared by Pickering Emulsion Polymerization and Its Adsorption and Optical Sensing Performance.

A novel, molecularly imprinted, upconversion fluorescence probe (UCNP@MIFP) for sulfonamide sensing was fabricated by Pickering emulsion polymerization using UCNP@SiO2 particles as the stabilizer and sulfamethazine/sulfamerazine as the co-templates. The synthesis conditions of the UCNP@MIFP were optimized, and the synthesized probe was characterized by scanning electron microscopy, Fourier transform infrared spectrometer, thermogravimetric analyzer, and fluorescence spectrometer. The UCNP@MIFPs showed a good adsorption capacity and a fast kinetic feature for the template. The selectivity experiment revealed that the UCNP@MIFP has a broad-spectrum molecular recognition capability. Good linear relationships were obtained over the concentration range of 1-10 ng/mL for sulfamerazine, sulfamethazine, sulfathiazole, and sulfafurazole, with low limits of detection in the range of 1.37-2.35 ng/mL. The prepared UCNP@MIFP has the potential to detect four sulfonamide residues in food and environmental water.

Synthesis of uniform Pickering microspheres doped with quantum dot by microfluidic technology and its application in tumor marker

Tumor markers play a significant role in early cancer diagnosis, evaluation of the extent of the disease, and monitoring of therapy response. In this study, we described the Pickering emulsion polymerization method to synthesize uniform magnetic/fluorescent microspheres. A Pickering-structure composed of a lot silica nanoparticle closely covered onto the quantum dot-encoded magnetic microbeads is designed and synthesized. The uniform magnetic/fluorescent microspheres were prepared using a microfluidic device and the performance of the microspheres synthesized by the instruments was evaluated by flow cytometry. To avoid fluorescence quenching and intrinsic toxicity, CdSe/ZnS core-shell quantum dot and Fe3O4 nanoparticle were successfully encapsulated into MFM microspheres using the microfluidic technology. Using this structure enables the facile realization of a theoretical 4 × 4 barcoding matrix combining two colors and four fluorescence intensity levels. Then, different optical codes were prepared by simple changing the emission wavelength and the intensity of the quantum dots. The resulting microsphere are combined with flow cytometer using two lasers for decoding of multiplex tumor markers. Moreover, the stability testing of microspheres demonstrated good performance for further application in detection of tumor markers as well. When applied for the high-throughput ultrasensitive detection of three tumor markers (CEA, CA125 and CA199) in a single sample, the detection limits of 0.027 ng/mL for CEA, 1.48 KU/L for CA125 and 1.09 KU/L for CA199 are achieved, which exhibit superior detection performance. Thus, Pickering-structure magnetic/fluorescent microspheres are promising for application in tumor markers.

Photo‐responsive cellulose nanocrystal modified fluorinated polyacrylate based on coumarin chemistry

AbstractPhoto‐responsive cellulose nanocrystal modified fluorinated polyacrylate was synthesized by environmentally friendly RAFT‐mediated Pickering emulsion polymerization using amphiphilic block copolymer modified cellulose nanocrystal poly(acrylic acid)‐g‐CNC‐g‐poly (hexafluorobutyl acrylate‐co‐7‐(2‐methacryloyloxyethoxy)‐4‐methylcoumarin) PAA‐g‐CNC‐g‐P (HFBA‐co‐CMA) (MCNC) as a stabilizer, and the photo‐responsive coumarin groups were introduced to endow it with self‐healing function. This paper mainly studied the effect of MCNC dosage on emulsion polymerization and latex film properties. The latex particle size and its distribution decreased as the MCNC dosage increased from 0.4 wt% to 1.0 wt%, and then increased afterwards. The mechanical property and thermal stability of latex films could be significantly improved by introducing MCNC. And the surface scratches of latex films with MCNC exceeding 0.4 wt% could be completely repaired after 7 h UV irradiation. Furthermore, the photo‐responsive cellulose nanocrystal modified fluorinated polyacrylate emulsion was applied to fabric finishing by dip‐rolling treatment. And the finished fabric had good hydrophobicity, oleophobicity and surface repair performance.

Dummy-template Pickering emulsion imprinted microspheres online pretreatment and analysis for the estrogens in cosmetics

Estrogens are a class of steroid hormone with strong physiological activity. Due to the pronounced beauty effect, such drugs are highly susceptible to illegal addition and cause other adverse effects. To avoid template leakage and the negative impacts on the environment caused by the estrogens, diosgenin was selected as the dummy template due to its similar skeleton structure. The Pickering emulsion polymerization was used to obtain the dummy-template molecularly imprinted polymers (dt-MIPs). Scanning electron microscopy, optical microscopy, specific surface area testing, Fourier transform infrared spectroscopy and adsorption experiments were used to characterize the apparent morphology and the recognition performance of the microspheres. Then, the prepared microspheres and commercial fillers were used to construct an on-line solid phase extraction (on-line SPE) analytical system coupled with HPLC via a two-position switching valve. On-line solid phase extraction-HPLC analytical methods were established and verified, for the simultaneous determination of four estrogens in cosmetic samples. The accuracy and precision RSDs for the established methods using the imprinted sorbents were 92.00–104.02% and less than 9.12%, respectively. All four estrogens exhibited good linearity in the range of 0.05 to 5 µg/mL with a coefficient of determination R2 greater than 0.9810. The method comparison results suggest that the established analytical method is simple in pre-treatment, easy to automate, and has excellent sensitivity to meet the analytical requirements of complex samples.