Amount Of MPS Research Articles

Effect of Halides on MPS Orientation and Cu Deposition Rates at Cu Surfaces

Surface enhanced Raman spectroscopy (SERS), electrochemical measurements, and contact angles were used to evaluate the effect of halides on Cu electrodeposition rates in the presence of 3-mercapto-1-propanesulfonate (MPS). The Cu(II) reduction rate was shown to decrease in the order Cl− > Br− > I−. In-situ SERS and contact angle measurements showed that adsorbed MPS will exhibit decreased gauche to trans (g:t) ratio and decreased hydrophobicity in the same order as the Cu(II) reduction rate. The amount of MPS in the gauche form, due to the hydrophobicity of the halide decorated surface, is a key factor in the Cu(II) reduction rate in acid sulfate baths containing the accelerator.

Label-free amperometric immunosensor based on prussian blue as artificial peroxidase for the detection of methamphetamine

A label-free amperometric immunosensor for the detection of methamphetamine was developed. The prussian blue deposited/l-cystine-modified electrode was covered with nano-Au/(3-mercaptorpropyl) trime-thoxysilane film. Then, the nano-Au was used for the immunosensor platform to capture a large amount of anti-methamphetamine. PB exhibited excellent electrocatalytical properties toward the reduction of H2O2 at low overpotentia to amplify the amperometric signal, which enhanced the sensitivity of the immunosensor. The active sites of PB could be shielded and the access of H2O2 from solution to the electrode might be partially blocked after the completion of immunoassay, led to a linear decrease in the response current of the electrode over the range from 1.0×10−8 to 5.0×10−6molL−1of MA. The obtained immunosensor displayed excellent catalytic reduction toward H2O2 due to high activity and selectivity of PB. The influence of relevant experimental variables, including the construction of immunosensor platform, the amount of MPS and the time of immunoaction, was examined and optimized.

Dielectric Studies of Admicelled Natural Rubber with Poly(3-Trimethoxysilylpropyl Methacrylate)

In this work, 3-trimethoxysilylpropyl methacrylate (MPS) was used as a substrate for coating on natural rubber (NR) particles by admicellar polymerization. The incorporation of MPS monomer, consisting of silicon element and 3 reactive methoxy groups (R-Si(OCH3)), is expected to increase dielectric properties of NR. Under the admicellar polymerization, the R-Si(OCH3) groups can be hydrolyzed and condensed into polysiloxane existed on NR particles. This method aims to prepare composite materials from NR and MPS with various amounts of MPS. The effects of microwave frequency and chemical modification by admicellar polymerization were studied. The dielectric properties of admicelled natural rubber (adNR) with PMPS were investigated at 20 °C in a frequency range extended from MHz to GHz. The results showed that the dielectric constant of adNR increased with PMPS contents. To study the effect of crosslinking on the dielectric properties of adNR, the dielectric spectroscopy measurements were performed on prevulcanized and non-prevulcanized adNR. The investigation showed that the dielectric constant of non-prevulcanized adNR was less than prevulcanized adNR.

De-Agglomeration and Dispersion Behavior of TiO2 Nanoparticles in Organic Media Using 3-Methacryloxypropyltrimethoxysilane as a Surface Modifier

Titania (TiO2) nanopowder was de-agglomerated in butyl acetate (BAc) via a bead milling process in the presence of 3-methacryloxypropyltrimethoxysilane (MPS), and subsequently centrifuged to obtain the TiO2 nanoparticles dispersions with high transparency. The transparent TiO2 dispersions were further incorporated into various ultraviolet (UV)-curable formulations to examine the dispersion behavior of MPS-functionalized TiO2 (MPS-TiO2) nanoparticles in UV-curable organic media. Higher molar ratio of MPS/TiO2 causes better de-agglomeration of TiO2 nanoparticles in BAc, higher amount of MPS attached, and better stabilization of MPS-TiO2 nanoparticles, suggesting the excellent compatibility of MPS-TiO2 nanoparticles with BAc. However, a critical MPS-TiO2 load producing phase separation of MPS-TiO2 nanoparticles exists for the dispersion of MPS-TiO2 nanoparticles in UV-curable monomers or polyurethane (PU)/monomer mixtures. Higher fraction of PU in organic media leads to lower critical MPS-TiO2 load or even serious phase separation at extremely low TiO2 content. The lower the amount of the grafted MPS is, the higher the critical MPS-TiO2 load is. It implies that MPS-TiO2 nanoparticles are partially compatible with UV-curable monomers and incompatible with PU oligomer.

Thionate versus Oxon: Comparison of Stability, Uptake, and Cell Toxicity of (14CH3O)2-Labeled Methyl Parathion and Methyl Paraoxon with SH-SY5Y Cells

The stability, hydrolysis, and uptake of the organophosphates methyl parathion and methyl paraoxon were investigated in SH-SY5Y cells. The stabilities of ((14)CH(3)O)(2)-methyl parathion ((14)C-MPS) and ((14)CH(3)O)(2)-methyl paraoxon ((14)C-MPO) at 1 microM in culture media had similar half-lives of 91.7 and 101.9 h, respectively. However, 100 microM MPO caused >95% cytotoxicity at 24 h, whereas 100 microM MPS caused 4-5% cytotoxicity at 24 h ( approximately 60% cytotoxicity at 48 h). Greater radioactivity was detected inside cells treated with MPO as compared to MPS, although >80% of the total MPO uptake was primarily dimethyl phosphate (DMP). Maximum uptake was reached after 48 h of (14)C-MPS or (14)C-MPO exposure with total uptakes of 1.19 and 1.76 nM/10(6) cells for MPS and MPO, respectively. The amounts of MPS and MPO detected in the cytosol after 48 h of exposure time were 0.54 and 0.37 nM/10(6) cells, respectively.

STUDY OF NANO-SILICA/FLUORINATED ACRYLATE COPOLYMER HYBRID EMULSION AND THE POLYMERIZATION KINETICS

Perfluorinated polymers are of high scientific and technological interest owing to their unique characteristics.However,their utilization is limited due to their poor cohesiveness,film-forming properties and high cost.When perfluorinated polymers are incorporated with polyacrylate,remarkable properties are exhibited with higher performance price ratio;that is,oil and water repellency of the former is unmitigated while the mechanical strength and cohesiveness of the latter are retained.As an inexpensive functional component,incorporated silica can shield polymeric matrix from the UV,while reinforcement and improved thermal stability are achieved,as well as better rinse-resistance,perdurability and self-cleanness effects. In this paper,nano-silica and poly(MMA-co-nBAco-FA) were combined with covalent bonds.Not only extraordinary properties derived from each individual component were retained,but also a more intimate cooperation was provided between the twos,through an environment-friendly method. At first,the monodisperse silica was prepared in ethanol according to the well-known Stber procedure,followed by modification via addition of γ-methacryloxy propyltrimethoxysilane(MPS).Then,the nano-silica/poly(MMA-co-nBA-co-FA) hybrid emulsion was prepared via in-situ emulsion polymerization in the presence of MPS-grafted silica. The chemical compositions and morphologies of both nano-silica and silica/poly(MMA-co-nBA-co-FA) nanocomposites(NPs) were characterized by Fourier-transform infrared(FT-IR) spectrometry and transmission electron microscopy(TEM),respectively.From TEM images,it was obvious that uniform spherical nano-silica was obtained,with average diameter of 20 nm.FT-IR effectively proved the occurrence of MPS-grafting reaction.According to the amount of MPS added,the MPS-grafted density of nano-silica was determinated as 0.1716 μmol/m~2. Off-centre core-shell structures of silica/poly(MMA-co-nBA-co-FA) NPs were confirmed by TEM images.Approximately 50% of NPs had more than one single core due to the congregating of smaller particles when the diameters of the core were not larger than 100 nm.Under a low MPS-grafted density,not all of monomers were polymerized and connected with MPS on the grafted silica,and most of the polymer chains were twisted and absorbed around the core particles,followed by copolymerization with polymer layer copolymerized with MPS,resulted in an off-centre core-shell structure ultimately. Thermal stability of silica/poly(MMA-co-nBAco-FA) NPs was studied via thermal gravimetric analysis(TGA).The results showed that higher initiative decompose temperature was achieved with more nano-silica incorporated,which implicated the successful encapsulation of silica into NPs,as well as enhanced thermal stability. The surface properties of the latex films produced from silica/poly(MMAco-nBA-co-FA) NPs were also investigated by contact angle method and water absorption measurements.Obviously,the incorporation of silica and FA contributed to degressive surface-free energy,with a minimum value of 9.8 mN/m.Similarly,water absorption ratio decreased with increasing contents of nano-silica and FA.What worth noting was the abnormal polar and disperse component of surface-free energy,which might be attributed to nano-silica's incorporation and distribution while film-forming.Besides these,the kinetics of in situ emulsion polymerization,in which MPSgrafted silica with a low grafted density was introduced,had been investigated in details.The results can be summarized as follows: R_p∝~(0.25)[SiO_2]~(0.31)[I]~(0.66)~(0.757) while [SiO_2]8.9×10~-2 mol·L~-1,and R_p∝~(0.25)[SiO_2]~(-1.33)[I]~(0.66)[E]~(0.757) while [SiO_2]8.9×10~-2 mol·L~-1.The overall activation energy of the polymerization was calculated to be 83.15 kJ/mol.

Synthesis of Hybrid Core−Shell Nanoparticles by Emulsion (Co)polymerization of Styrene and γ-Methacryloxypropyltrimethoxysilane

Core−shell nanoparticles with a polystyrene core and a hybrid copolymer shell were synthesized via emulsion polymerization of styrene and subsequent addition of γ-methacryloxypropyltrimethoxysilane (MPS) to produce the shell by copolymerization reaction of MPS with the residual amount of styrene. The influences of pH, the amount of MPS, and the addition mode of MPS on the particles size, morphology, and copolymer architecture in the shell were studied using dynamic light scattering (DLS), transmission electron microscopy (TEM), gas chromatography (GC), differential scanning calorimetry (DSC), solid-state NMR, and infrared (IR) spectroscopy.