Emulsifier-free Polymerization Research Articles

Fluorine-silicon/N+ modified waterborne acrylic coatings with good anticorrosion and antibacterial performances

Most conventional organic coating resins typically have single anticorrosion function and additive bactericides are often needed to improve their antibacterial properties. In this paper, a waterborne acrylic coating (fluorine-silicon/N+ polyacrylate) with the chemically bonded antibacterial constitutional units have been successfully synthesized via simple soap free emulsion polymerization. The results showed that the antibacterial rate of fluorine-silicon/N+ polyacrylate coating against Staphylococcus aureus and Escherichia coli were 99.99 % and 99.08 %, respectively. In addition, the low frequency impedance model value of coatings (at 0.01 Hz) maintained above 109 Ω cm2 during 10 d immersion in neutral 3.5 wt% NaCl solution. Thus, the fluorine-silicon/N+ polyacrylate coating possesses good antibacterial and anticorrosion performances.

Strengthening polylactic acid (PLA) composites with poly(methyl methacrylate)-functionalized cellulose nanofibrils created through grafting-through emulsion polymerization

Aqueous surfactant free emulsion grafting-through polymerization produced poly(methyl methacrylate) coated cellulose nanofibrils that retained microstructure and strengthened poly(lactic acid) composites.

Design and fabrication of superamphiphobic coating based on raspberry-like F–SiO2@PSA hybrid nanocomposite particles

Emulsifier-free polymerization was employed to prepare the submicron spherical PSA (the copolymer of styrene and acrylic acid), then SiO2 was grown on the surface of the PSA by sol-gel method to form F–SiO2@PSA particles. It was found that when styrene: acrylic acid = 2.5:1 and tetraethyl orthosilicate: PSA was between 2.17:1 and 6.38:1, a perfect raspberry-like structure could be obtained. The coating based on F–SiO2@PSA particles exhibited contact angles of 167.3 ± 1.4°, 152.1 ± 1.5°,150.3 ± 1.6°, 150.9 ± 1.6°, 142.2 ± 1.7°, 143.7 ± 1.5° and 146.6 ± 1.9° to water, diiodomethane, soybean oil, rapeseed oil, hexadecane, kerosene, and waste engine oil, respectively. The F–SiO2@PSA coating could reduce the adsorption of protein by 90% compared with the control surface. It was observed that bacteria and platelets could hardly adhere to the coating surface after 24 h of E. coli culture and 3 h of platelet-rich plasma immersion. The anti-adhesion to proteins, platelets, and bacteria will give the coating a promising application in the medical field.

Thermo-Sensitive Microgel/Poly(ether sulfone) Composited Ultrafiltration Membranes.

Thermo-sensitive microgels known as PMO-MGs were synthesized via surfactant free emulsion polymerization, with poly(ethylene glycol) methacrylate (OEGMA475) and 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA) used as the monomers and N, N-methylene-bis-acrylamide used as the crosslinker. PMO-MGs are spherical in shape and have an average diameter of 323 ± 12 nm, as determined via transmission electron microscopy. PMO-MGs/poly (ether sulfone) (PES) composited ultrafiltration membranes were then successfully prepared via the non-solvent-induced phase separation (NIPS) method using a PMO-MG and PES mixed solution as the casting solution. The obtained membranes were systematically characterized via combined X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy and contact angle goniometer techniques. It was found that the presence of PMO-MGs significantly improved the surface hydrophilicity and antifouling performance of the obtained membranes and the PMO-MGs mainly located on the channel surface of the membranes. At 20 °C, the pure water flux increased from 217.6 L·m-2·h-1 for pure PES membrane (M00) to 369.7 L·m-2·h-1 for PMO-MGs/PES composited membrane (M20) fabricated using the casting solution with 20-weight by percentage microgels. The incorporation of PMO-MGs also gave the composited membranes a thermo-sensitive character. When the temperature increased from 20 to 45 °C, the pure water flux of M20 membrane was enhanced from 369.7 to 618.7 L·m-2·h-1.

Preparation and Characterization of Cellulose Nanoparticles from Agricultural Wastes and Their Application in Polymer Composites

, Page no - | ABSTRACT | PDF | FULL TEXT | e-PUB Background: The development of innovative eco-sustainable bio-nano-composites materials based on cellulose nanomaterials obtained from agricultural waste such as rapeseed plant straw and polymeric materials with improved properties. At first, cellulose was extracted from rapeseed plant straw and cellulosic and no cellulosic materials were estimated. It was found that the rapeseed plant straw contained about 43.48 wt.% cellulosic materials and 56.52 wt.% no cellulosic materials. It was also found that the rapeseed plant straw content about 34.84 wt.% α- cellulose. Then, nano-cellulose was prepared by acid hydrolysis of α -cellulose obtained from rapeseed plant straw. Poly vinyl acetate (PVAc) was prepared by soap free emulsion polymerization of vinyl monomer. Natural rubber (NR) collected as latex was oxidized by KMnO4. Blends of NR and oxidized NR with PVAc of different compositions such as NR60/PVAc40, NR40/PVAc60, ONR60/PVAc40, ONR40/PVAc60 were prepared by mixing NR latex and PVAc emulsion and followed by drying in an oven at 60°C. Composites of NR60/PVAc40 and ONR60/PVAc40 reinforced nano-cellulose (NC) were also prepared in similar way. The blends and composites were then characterized by FTIR, SEM, and Tensile test (TS). FTIR analysis confirmed the oxidation of NR and shown the variation of the functional groups in the blends and composites compared with the FTIR spectrum of NR, ONR and PVAc. SEM study exhibited that the nano-cellulose were dispersed within NR/PVAc and ONR/PVAc blends matrices with a little agglomeration. The tensile test results showed that the strength in composites was increased due to the reinforcing effect of nano-cellulose (NC). Objectives: The aim of this study is to assess the Preparation and characterization of binary blends of NR and oxidized NR with PVAc. Methods: This is an observational study. The study used to be carried out in the admitted patient’s Department of Applied Chemistry and Chemical Engineering, Islamic University, Kushtia-7003, Bangladesh. The duration of the period from Data was entered in MS Excel and Statistical analysis was done using SPSS trial version. Results: This study shows that the according to Constituent, Cellulose was 43.4822%, Alpha-Cellulose were 34.8427% and Cellulose were 8.6395%. And according to Source, Rice Straw were 32.15% %, Sugarcane were 41-43%, Rye Straw were 31.8-42.64%, Corn Stalks were 29.80% and Wheat Straw were 34-40%. Conclusion: Novel eco-friendly bio-nano-composites substances primarily based on renewable and sustainable assets namely natural rubber (NR) and nano-cellulose received from rapeseed plant straw as properly as poly vinyl acetate (PVAc) have been developed. In order to enhance the interfacial interactions amongst the composite factors such as NR, PVAc and NC, oxidation of the NR latex was once carried out by way of KMnO4 before blending mixing with PVAc emulsion and NC suspension.

In-situ healing of damaged polyethersulfone ultrafiltration membranes with microgels

The damage of water treatment membranes under operation is a thorny problem, resulting in a great reduction of separation performance and compromised water quality. Here, we shall report a facile method for in-situ reparation of damaged membranes by using damaged polyethersulfone (PES) ultrafiltration (UF) flat membranes as model systems and quaternized crosslinked microgels coded as PNI6 microgels as the healing materials. The PNI6 microgels were synthesized via surfactant free emulsion polymerization of N-isopropylacrylamide (NIPAM) and 1-vinylimidazole (VIM) in the presence of 1,6-dibromohexane (BrCH). The obtained PNI6 microgel suspension was used as the feeding liquid to successfully heal the wound of damaged PES UF flat membranes by filtration deposition. An absorbed microgel layer was formed on the wound site of membranes and hence healed the wound. The rejection performances of microgel-healed PES UF membranes were recovered to the original level of pristine membranes although the water flux decreased from 588.6 L/(m2 h bar) for the pristine membrane to 228.8 L/(m2 h bar) for the healed membranes. It was also demonstrated that the microgel-healed PES UF membranes were chemically stable in both strong acidic and basic conditions and durable in a wide temperature range from 25 to 70 °C with a long-term stability.

Synthesis of Glucose/Fructose Sensitive Poly(ethylene glycol) Methyl Ether Methacrylate Particles with Novel Boronate Ester Bridge Crosslinker and their Dye Release Applications.

In this study, it is aimed to develop glucose/fructose sensitive poly(ethylene glycol) methyl ether methacrylate (PEGMA) particles which can be employed in controlled drug delivery applications. For this purpose, a boric acid based crosslinker was synthesized using 4-vinylphenylboronic acid and its formation was confirmed by 1H-NMR and FT-IR analyses. Sugar-sensitive polymeric particles were then achieved using this crosslinker and PEGMA monomer in single step and surfactant free emulsion polymerization technique. Polymeric particles were characterized by DLS, SEM, and TEM in terms of size and morphology. In order to determine the sensitivity of the particles to sugar molecules, first Rhodamine B dye (as a model drug) loading experiments were performed. Then, the particles were subjected to glucose/fructose rich media and dye release was monitored as a function of time using UV-Vis spectrophotometry. The results of the current study revealed that the PEGMA particles were more sensitive to fructose (~39% release) compared to glucose (~25% release) at pH 7.4 and 310 K.

A COMPARATIVE STUDY OF PARTICLES CHARACTERISTICS, TEMPERATURE SENSITIVITY AND MORPHOLOGY OF PEG/POLY (NIPAM-CO-AMPS) MICROGELS

The temperature sensitive copolymer of microsize hydrogels consist of N-isopropylacrylamide (NIPAM) and 2- acrylamido-2 methylpropanesulphonic acid (AMPS) have been synthesized by soap free emulsion polymerization method in the presence of polyethylene glycol (PEG) as macro initiator and N, N´-methylenebisacrylamide (NMBA) as crosslinker. In this work, Dynamic Light Scattering (DLS), Transmission Electron Microscope (TEM) and Atomic Force Microscope (AFM) technique were used for structural analysis of microgels. It was found that particle size observed by TEM and AFM were spherical with a diameter around 103.0 nm to 133.1 nm and 121.1 nm to 189.0 nm. While DLS measurement shows narrow particle size distribution with hydrodynamic diameter from 343.6nm to 528 nm at a temperature 25°C and 132.5nm to 414.4nm at temperature 50°C depending on the AMPS content in Microgels samples. The surface roughnesses of particles were observed to be increasing with increased AMPS content. Moreover, decrease in hydrodynamic diameter from 25°C to 50°C revealed the temperature sensitivityproperty of microgels.

Lipophilic monomer tackifying hydrogel antifouling coatings prepared by soap free emulsion polymerization and its performance

Lipophilic monomer tackifying hydrogel with good adhesion ability on organic substrates prepared in oily systems contain a large number of volatile organic compounds(VOCs). In this study, lipophilic monomer tackifying hydrogel prepolymers were fabricated in an aqueous system by soap-free emulsion polymerization to solve the above problems. The effects of reaction temperature, monomer type and comonomer ratio on soap-free emulsion polymerization were investigated. The structure of the hydrogel antifouling material was characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The adhesion properties of the lipophilic monomer tackifying hydrogel antifouling material on the organic substrate were investigated by a “static seawater immersion panel experiment” and “dynamic rotating seawater experiment”. The antifouling ability of the lipophilic monomer tackifying hydrogel was investigated by inhibiting the adhesion of microalgae and bovine serum albumin (BSA) and panels tests in a real marine environment. The results showed that the lipophilic monomer tackifying hydrogel antifouling material with good adhesion on an organic substrate was successfully prepared by soap-free emulsion polymerization. When the molar content of butyl acrylate was 30%, it did not fall off after 28 days of the dynamic rotating experiment. The change in water absorption caused by the acrylic acid content has a direct impact on protein adhesion. Panels in the real marine environment experiments displayed that the lipophilic monomer tackifying hydrogel had considerable inhibitory ability on biological attachment.

Influence of the composition of macromolecular diols on the rheology and water absorption of polyurethane acrylate emulsions

AbstractWaterborne modified polyurethane (PU) dispersions with different macromolecular diols as soft segments were prepared by the self‐emulsifying method, and then compounded with the acrylate monomers, the polyurethaneacrylate composite emulsion (PUA) with the core‐shell structure was prepared by emulsifier free emulsion polymerization. The effects of the type and ratio of macromolecular diols in the soft segment on the particle size and distribution, rheological properties, adhesion, water absorption and thermal properties of the PUA emulsion were studied. The results showed that the particle size of PUA decreased, and the shear resistance and heat resistance of PUA were enhanced with the addition of polypropylene glycol. According to the water absorption rate of PUA emulsion, it was found that adding poly‐1,4‐butanediol adipate glycol and poly(caprolactone) diol with more hydrophobic groups could improve the water resistance of PUA dry film, and the minimum water absorption value was 0.68%.

Synthesis and structural characterization of energy crop peelu methyl esters, using hybrid metallic nano-particles. A step forward to bioenergy industry

In the present research project, the energy crop peelu non-edible oil was investigated as a potential source for fatty acid methyl esters production, using hybrid metallic nano-particles. The energy crop peelu is an evergreen shrubby plant distributed throughout the tropical and subtropical regions of the world. Naturally, the plant has having a worthy fates masses, had proceeded an optimum results for quantitative and qualitative methyl esters production, using hybrid metallic nano-particles poly-N-isopropylacrylamide “PNIPAM-Cu, PNIPAM-Pd & PNIPAM-Cu@Pd”. Whereas, the carboxyl functionalized P(NIPAM) microgels was synthesized via soap free emulsion polymerization, containing poly-N-isopropyl acrylamide and acrylic acid. The proposed thiol group was then introduced via carbodiimide mediated imide bond between the carboxyl group of carboxyl functionalized microgels and the amine from amino-ethanethiol. The Copper, Palladium and Copper@Palladium nano-particles were mixed-up into thiol-functionalized Poly-N-isopropylacrylamide microgels through metals thiol linkage. The hybrid metallic nano-particles were characterized using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) & Fourier Transfer Infra-Red (FT-IR) for rectification. The experimentation protocol for methyl esters synthesis using various concentrations of hybrid metallic nano-particles in conversion was adjusted to 1:6 oil to methanol molar ratio, temperature 60 °C and reaction time 2 h and stirring 600 rpm, respectively. The optimum yield of methyl esters was reported 92.20 against 1.5gm PNIPAM-Cu@Pd nano-particle. The chemical and structural status of synthesized methyl esters were characterized by Gas Chromatography & Mass Spectroscopy (GC&MS), FT-IR & Nuclear Magnetic Resonance) NMR spectroscopes. The physico-chemical properties of peelu crop methyl esters were analyzed, checked and compared with the international American Standards for Testing Materials (ASTM) & European Union (EN) standards, accordingly.

Biomass-derived fluorinated corn starch emulsion as binder for silicon and silicon oxide based anodes in lithium-ion batteries

In this work, an in situ crosslinked network is prepared as the binder of silicon (Si), Si-graphite and silicon oxide (SiO)-graphite anodes. Fluorinated hydrolyzed corn starch synthesized by emulsifier-free polymerization is mixed with equal corn starch and 0.1 mg mL−1 dopamine, consequently form reversible interactions with electrode particles and copper foil, which plays a vital role in maintaining electrode structural integrity. It is found that the electrochemical performances of Si electrodes are heavily influenced by fluorinated carbon atoms and space linker groups of perfluoroalkyl side chains in polymeric binder. Binder with poly(N-methylperfluorobutane-1-sulfonamide ethyl acrylate) side chains (SSC4SA) exhibits the best performance, which realizes an initial discharge capacity of 3801 mAh g−1 and 88.0% capacity retention at 1 A g−1 after 100 cycles. Si-graphite and SiO–graphite composite electrodes with the mass ratio of 15:73 are prepared applying SSC4SA binder. The capacity retention of composite electrodes are 58.7% and 95.6% after 200 and 500 cycles respectively, which are far superior to commercial carboxyl methyl cellulose-styrene butadiene rubber (CMC-SBR) binder based electrodes. Such simply preparation method and the understanding of design principles for silicon anode binders in molecular-level are useful for further fundamental researches and practical applications.

Different Strategies for the Preparation of Galactose-Functionalized Thermo-Responsive Nanogels with Potential as Smart Drug Delivery Systems.

Different synthetic strategies were tested for the incorporation of galactose molecules on thermoresponsive nanogels owing to their affinity for receptors expressed in cancer cells. Three families of galactose-functionalized poly(N-vinylcaprolactam) nanogels were prepared with the aim to control the introduction of galactose-moieties into the core, the core-shell interface and the shell. First and second of the above mentioned, were prepared via surfactant free emulsion polymerization (SFEP) by a free-radical mechanism and the third one, via SFEP/reversible addition-fragmentation chain transfer (RAFT) polymerization. Synthetic recipes for the SFEP/free radical method included besides N-vinylcaprolactam (NVCL), a shell forming poly(ethylene glycol) methyl ether methacrylate (PEGMA), while the galactose (GAL) moiety was introduced via 6-O-acryloyl-1,2,:3,4-bis-O-(1-methyl-ethylidene)-α-D-galactopiranose (6-ABG, protected GAL-monomer): nanogels I, or 2-lactobionamidoethyl methacrylate (LAMA, GAL-monomer): nanogels II. For the SFEP/RAFT methodology poly(2-lactobionamidoethyl methacrylate) as GAL macro-chain transfer agent (PLAMA macro-CTA) was first prepared and on a following stage, the macro-CTA was copolymerized with PEGMA and NVCL, nanogels III. The crosslinker ethylene glycol dimethacrylate (EGDMA) was added in both methodologies for the polymer network construction. Nanogel’s sizes obtained resulted between 90 and 370 nm. With higher content of PLAMA macro-CTA or GAL monomer in nanogels, a higher the phase-transition temperature (TVPT) was observed with values ranging from 28 to 46 °C. The ρ-parameter, calculated by the ratio of gyration and hydrodynamic radii from static (SLS) and dynamic (DLS) light scattering measurements, and transmission electron microscopy (TEM) micrographs suggest that core-shell nanogels of flexible chains were obtained; in either spherical (nanogels II and III) or hyperbranched (nanogels I) form.

Graft PEI ultra-antiwear nanolayer onto carbon spheres as lubricant additives for tribological enhancement

A facile and characteristic one-step emulsifier-free polymerization strategy was proposed to graft a poly (ethylene imine) (PEI) nanolayer onto carbon spheres (CS) surface, forming an amphiphilic particle, and to apply as an efficient lubricating additive to improve the tribological performances of traditional lubricating oils. Hybrid lubricants, containing carbon spheres/poly (ethylene imine) (CS-PEI) particles dispersed in engine oil, were evaluated regarding their tribological performances under ball-on-disk tribometry. The steel substrates lubricated by CS-PEI showed clearly improved, with a significant reduction in the friction and wear (15–42%). These tribological improvements were attributed to several functions of CS-PEI additives, including: Ⅰ) bearing and filling mechanisms, Ⅱ) superior wear and friction resistances, Ⅲ) formation of PEI lubrication films with lower shear-strength on contact interfaces.

Electrorheological display loading medium of core/shell polystyrene/polyvinyltetrazole microspheres for on-site visualization of lead(II)

Polystyrene microspheres (PSM) were obtained by emulsifier-free polymerization to coat polyacrylonitrile (PSM@PAN) as core/shell-structured microspheres of precursors. Core/shell polystyrene/polyvinyltetrazole (PSM@PVT) microspheres were obtained after a cyano-to-tetrazole conversion reaction loaded in an electrorheological display (ERD) that exhibits a low transmittance in the absence of an alternating electric field (AEF). The microspheres carrying negative and positive charges at two sides bound to each other as column-like structure along the direction of AEF enhancing the transmittance. Characteristic frequency (Fc), regarded as a mark to monitor the shell component, is defined to generate the highest degree of transmittance under an AEF. Fc of PSM@PVT shifted from 350 kHz to 100 kHz after the adsorption of lead(II) within the PVT coating. Transmittance of the ERD loading of PSM@PVT with lead(II) increased linearly with the concentration of lead(II). Approximately 30 ng mL−1 of the limit of detection was recognized within 10 s according to ERD transmittance under an AEF at 100 kHz. The Fc of the PSM@PVT absorbing the lead(II) was not influenced by the Na(I), K(I), Ca(II), Mg(II), Fe(III), and Zn(II) coexisting in the ERD. This platform provides a simple technology for heavy ion detection and may be a potential on-site ion-visualizing sensor.

Cr(VI) visualization via transmittance of electrorheological display medium with core/shell polystyrene/polyvinyltetrazole microspheres

In the course of time, significant amounts of heavy-ion pollutants have been dispersed into the environment. Rapid on-site detection of heavy metal ions is crucial to monitor their dispersion in the nascent stages. In this study, 2.2-μm-diameter polystyrene microspheres (PSM) were synthesized via emulsifier-free polymerization to coat polyacrylonitrile (PSM@PAN) and form core/shell-structured microspheres. Core/shell polystyrene/polyvinyltetrazole (PSM@PVT) microspheres were obtained after a cyano-to-tetrazole conversion reaction, loaded in an electrorheological device (ERD) display constructed using two indium tin oxide glasses with a spacer seal. The ERD loading dispersed the microsphere solution by scattering light through the ERD, resulting in a low transmittance in the absence of an alternating electric field (AEF). Particles in the fluid medium were polarized to induce negative and positive charges at each end of the particles under the AEF, and the resultant particle chains enhanced transmittance. The optimal frequency to generate the highest degree of particle chaining in the presence of an AEF is defined as its characteristic frequency (Fc), which also serves as an indicator to identify the shell materials. The Fc of PSM@PVT shifted from 350 kHz to 30 kHz after adsorbing Cr(VI) from the PVT coating. Transmittance of the ERD loading of PSM@PVT with Cr(VI) increased linearly with the concentration of Cr(VI). Approximately 40 ng mL−1 of the limit of detection was calculated in the linear range of 10–540 ng mL−1. The Fc of the PSM@PVT adsorbing the Cr(VI) was not influenced by Na(I), K(I), Ca(II), Mg(II), Fe(III), and Zn(II) coexisting in the ERD.

Synthesis and tribological applications for carbon microspheres/poly (methyl methacrylate)/poly (ethylene imine) amphiphilic particles

Carbon microspheres/poly (methyl methacrylate)/poly (ethylene imine) (CMS/PMMA/PEI) amphiphilic particles were prepared by a facile one-step emulsifier-free polymerization method. The resulting perfectly spherical shapes with well-defined core–shell-shell structures were demonstrated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The tribological performances of proposed lubricant additives were dispersed in a reference oil (Ref-Oil, 85W-90) and evaluated using ball-on-disk (BOD) configurations. In the best case, the hybrid lubricant containing 0.2-wt% CMS/PMMA/PEI exhibited a substantial reduction in friction and wear (28–59%) compared to without additives. Raman, TEM, and SEM investigations of CMS/PMMA/PEI particles following long-time tribo-testing exhibited their excellent mechanical and chemical stabilities. These tribological enhancements were attributed to the bearing and filling mechanisms of these spherical particles and their superior lubrication effects of PMMA/PEI multishells. This novel core-shell-shell particle showed a great potential candidate for oil-based lubrication.

Carbon supported PdNi alloy nanoparticles on SiO2 nanocages with enhanced catalytic performance

Here we present a simple approach for the fabrication of Pd–Ni alloy nanoparticles embedded in a carbon layer on raspberry-like SiO2 hollow nanocages (SiO2@C-PdNi).

Polishing behavior of PS/SiO2 Core-Shell nanoparticles with different shell thickness on fused silica Chemical Mechanical Polishing

The core-shell PS/SiO2 composite nanoparticles as abrasives with different shell thickness was researched in fused silica chemical mechanical polishing (CMP) for the first time. The polystyrene nanoparticles were prepared by using emulsifier-free polymerization method first, then the PS/SiO2 with different shell thickness were synthesized by modified Stöber method. The morphologies of PS/SiO2 monodisperse nanospheres were characterized with scanning electron microscopy (SEM). The elastic moduli of single nanoparticle was measured by atomic force microscopy (AFM). The CMP results indicated that the material remove rate (MRR) has been obviously improved with as-prepared nanospheres (21 – 31 nm/min). There was a trend that MRR is rising when the shell thickness is between 200 and 50nm and then falling when the shell thickness is 35nm. Based on the small deformation theory, the finite element analysis was used to simulate the indentation depth and radius of the contact area between the individual particle and the wafer. Then a reasonable explanation for the experimental results was put forward. This research pave a way for realizing the optimization of CMP and material precise removal in the future.

Ultrasensitive and selective detection of MnO4− in aqueous solution with fluorescent microgels

The novel functional microgels, namely PNI-MSPC microgels, were fabricated via surfactant free emulsion polymerization (SFEP) by using N-isopropylacrylamide (NIPAm) as the monomer and a home-designed dichlorinated 1,1′-di[4-(vinyl)benzyl]-4,4′-pyridinium salt (MSPC2+.2Cl−) as the cross-linker. The PNI-MSPC microgels exhibited not only thermo-sensitivity but also redox actuatable hydrodynamic diameter and fluorescence properties. The PNI-MSPC microgels were successfully applied as the fluorescent sensor for ultrasensitive and selective detection of trace MnO4- anions in aqueous solutions. The presence of MnO4- anions led to the significant fluorescence quenching of the PNI-MSPC microgels with a fast response time of 5 min. The limit of detection (DL) for MnO4- anions can reach 25 nM with a linear concentration range of 0–50 μM. The co-existence of 16 other species of anions or 17 species of metal ions did not interfere with the detection of trace MnO4- anions in aqueous solutions. The potential applications of the PNI-MSPC microgels for sensing trace MnO4- anions in real world samples were also validated.