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Highlights Copolymer of divinylphenyl-acryloyl chloride copolymers (PDVB- co -PACl) is designed and synthesized to graft on the surface of aluminum nitride (AlN) to improve its hydrolysis resistance. AlN fillers functionalized by PDVB- co -PACl with the molecular weight of 5100 g mol -1 exhibits the highest hydrolysis resistance and the lowest interfacial thermal resistance. When the mass fraction of AlN@PDVB- co -PACl is 75 wt% and the grafting density of PDVB- co -PACl is 0.8 wt%, the λ for AlN@PDVB- co -PACl/PMHS composites is 1.14 W m -1  K -1 and maintains 99.1% after soaking in 90 °C deionized water for 80 h. A series of divinylphenyl-acryloyl chloride copolymers (PDVB- co -PACl) is synthesized via atom transfer radical polymerization employing tert-butyl acrylate and divinylbenzene as monomers. PDVB- co -PACl is utilized to graft on the surface of spherical aluminum nitride (AlN) to prepare functionalized AlN (AlN@PDVB- co -PACl). Polymethylhydrosiloxane (PMHS) is then used as the matrix to prepare thermally conductive AlN@PDVB- co -PACl/PMHS composites with AlN@PDVB- co -PACl as fillers through blending and curing. The grafting of PDVB- co -PACl synchronously enhances the hydrolysis resistance of AlN and its interfacial compatibility with PMHS matrix. When the molecular weight of PDVB- co -PACl is 5100 g mol −1 and the grafting density is 0.8 wt%, the composites containing 75 wt% of AlN@PDVB- co -PACl exhibit the optimal comprehensive performance. The thermal conductivity ( λ ) of the composite is 1.14 W m −1  K −1 , which enhances by 20% and 420% compared to the λ of simply physically blended AlN/PMHS composite and pure PMHS, respectively. Meanwhile, AlN@PDVB- co -PACl/PMHS composites display remarkable hydrothermal aging resistance by retaining 99.1% of its λ after soaking in 90 °C deionized water for 80 h, whereas the λ of the blended AlN/PMHS composites decreases sharply to 93.7%.

Healthcare-associated infections are a serious concern, particularly in patients with intravascular catheters. In this study, we developed a novel ampicillin-loaded polycaprolactone (PCL)-coated polyurethane catheter (PUC) wherein polymethylhydrosiloxane (PMHS) enhanced the adhesion between PCL and PUC, ensuring coating durability. PUC were first treated with PMHS, followed by PCL coatings containing 1, 3, or 6 wt% ampicillin. Antibacterial activity against Listeria innocua and Escherichia coli was evaluated using the plate counting method over 40 d. Scanning electron microscopy confirmed that the coating was uniform and stable for over 40 d. Furthermore, antibacterial efficacy was maintained for 10, 30, and 40 d for the 1, 3, and 6 wt% ampicillin coatings, respectively. Compared to the uncoated controls, the bacterial counts were reduced by over 99.9%. Thus, PMHS pretreatment of a catheter coated with ampicillin-loaded PCL exhibited sustained antibacterial activity. Our findings show PMHS enhances the coating adhesion and ensures gradual uniform degradation of the PCL layer.

Fabricating multifunctional superhydrophobic cotton fabric via a simple strategy is highly desirable for various applications but it is rare. Herein, we proposed a one step in-situ redox reaction strategy based on polymethylhydrosiloxane (PMHS) and [Ag(NH3)2]+ ions to endow cotton fabrics with both superhydrophobic and antibacterial properties. The obtained cotton fabrics show high repellency against common liquids like green tea, cola, milk, orange juice, coffee, NaCl, HCl, and NaOH solution, and possess significant antibacterial activity against both E. coli and S. aureus due to generated Ag nanoparticles. Even subjected to laundering, rubbing, acidic (pH 1)/alkaline (pH 13) solution attack, freezing at liquid nitrogen, or heating treatment (120 °C), the superhydrophobic and antibacterial properties of modified cotton fabrics can remain stable without being damaged, which is highly desirable for long-lasting anti-fouling, oil/water separation, and antibacterial applications. Considering the universality, simplicity, and scalability of the surface functionalization method, this proposal to develop novel multifunctional cotton fabrics with robust water repellent and antibacterial properties has promising and versatile applications in wide areas.

New composites produced with recycled waste are needed to manufacture more sustainable construction materials. This paper aimed to analyze the hygrothermal and mechanical performance of plasterboard with a polymethylhydrosiloxane (PMHS) content, incorporating recycled PET microplastic waste and varying factors such as PMHS dose, homogenization time, and drying temperature after setting. A cube-centered experimental design matrix was performed. The crystal morphology, porosity, fluidity, water absorption, flexural strength, and thermal conductivity of plasterboards were measured. The results showed that incorporating recycled PET microplastics does not produce a significant difference in the absorption and flexural strength of plasterboards. However, the addition of recycled PET reduced the thermal conductivity of plasterboards by around 10%.

    Polydimethylsiloxane (PDMS) is a common material as vitreous humor substitution in vitreoretinal surgery. PDMS is obtained from octamethylcyclotetrasiloxane (D4) monomer. However, alternative synthesis methods that might be more accessible or efficient under local conditions need to be developed. Therefore, finding other materials as an alternative to substitute vitreous humor is necessary. This article presents the results of the synthesis and characterization of polymethylhydrosiloxane (PMHS), produced using dichloromethylsilane (DCHS) as a precursor and dichloromethane (DCM) as a solvent, as a potential material for vitreous substitution in ophthalmological procedures. The focus is on exploring the two-stage process, namely the hydrolysis method to produce short-chain PMHS and the condensation method to produce long-chain PMHS that meet the requirements to be used as vitreous humor substitution. The polymerization process was accelerated by heating and assisted by potassium hydroxide (KOH). The short-chain PMHS had a viscosity of 50 mPa.s, a refractive index of 1.3954, and a surface tension of 18 mN/m, while the long-chain PMHS had a viscosity of 930 mPa.s, a refractive index of 1.3978, and a surface tension of 19 mN/m, respectively. The PMHS was characterized using FTIR spectroscopy and NMR spectroscopy. It was found that Si-H as a typical functional group of PMHS was observed from FTIR spectroscopy. From the NMR characterization, the possible long-chain PMHS structure is -O-{-SiH(CH3)-}n-O which shows that the sample has polymerized well producing long chains. All the characterization results of the synthesized PMHS showed that this material has potential as a candidate material for vitreous substitution.

Plasterboard is an important building material in the construction industry because it allows for quick installation of walls, partitions, and ceilings. Although a common material, knowledge about its performance related to modern polymers and fabrication conditions is still lacking. The present work analyzes how some manufacturing factors applied during the plaster board fabrication impact on some plasterboard properties, including water absorption, flexural strength, and thermal conductivity. The manufacturing variables evaluated are the dose (D) of polymethylhydrosiloxane (PMHS), the agitation time of the mixture (H), and the drying temperature of the plaster boards after setting (T). The results suggest that factors D, H, and T induce changes in the porosity and the morphological structure of the calcium sulfate dihydrate crystals formed. Performance is evaluated at two levels of each factor following a statistical method of factorial experimental design centered on a cube. Morphological changes in the crystals of the resulting boards were evaluated with scanning electron microscopy (SEM) and the IMAGEJ image analysis program. Porosity changes were evaluated with X-ray microcomputed tomography (XMT) and 3D image analysis tools. The length-to-width ratio of the crystals decreases as it goes from low PMHS dosage to high dosage, favoring a better compaction of the plasterboard under the right stirring time and drying temperature. In contrast, the porosity generated by the incorporation of PMHS increases when going from low-level to high-level conditions and affects the maximum size of the pores being generated, with a maximum value achieved at 0.6% dosage, 40 s, and 140 °C conditions. The presence of an optimal PMHS dosage value that is approximately 0.6–1.0% is evidenced. In fact, when comparing trails without and with PMHS addition, a 10% decrease in thermal conductivity is achieved at high H (60 s) and high T (150 °C) level conditions. Water absorption decreases by more than 90% when PMHS is added, mainly due to the hydrophobic action of the PMHS. Minimum water absorption levels can be obtained at high drying temperatures. Finally, the resistance to flexion is not affected by the addition of PMHS because apparently there are two opposing forces acting: on one hand is the decrease in the length–width ratio giving more compactness, and on the other hand is the generation of pores. The maximum resistance to flexion was found around a dosage of 0.6% PMHS. In conclusion, the results suggest that the addition of PMHS, the correct agitation time of the mixture, and the drying temperature reduce the water absorption and the thermal conductivity of the gypsum boards, with no significant changes in the flexural resistance.

Resol phenol–formaldehyde (PF) resin was modified with 2.5 and 5.0 wt% polymethylhydrosiloxane (PMHS). This study characterizes the modified resin and its subsequently fabricated glass fiber (GF)-reinforced composites (30–60 wt% GF). Formation of an organic–inorganic hybrid network, via reaction between Si-H groups of PMHS and hydroxyl (-OH) groups of the resol resin, was confirmed by FTIR and 1H NMR. DSC and TGA/DTG revealed enhanced thermal stability for PMHS-modified resin: the decomposition temperature of Resol–PMHS 5.0% increased to 483 °C (neat resin: 438 °C), and char yield at 800 °C rose to 57% (neat resin: 38%). The 60 wt% GF-reinforced Resol–PMHS 5.0% composite exhibited tensile, flexural, and impact strengths of 145 ± 7 MPa, 160 ± 7 MPa, and 71 ± 5 kJ/m2, respectively, superior to the unmodified resin composite (136 ± 6 MPa, 112 ± 6 MPa, and 51 ± 5 kJ/m2). SEM observations indicated improved fiber–matrix interfacial adhesion and reduced delamination. These results demonstrate that PMHS modification effectively enhances the thermo-mechanical properties of the PF resin and its composites, highlighting potential for industrial applications.

Polymethylhydrosiloxane (PMHS) has been considered to be developed as an alternative material of polydimethylsiloxane (PDMS) for vitreous humour substitution. This polymer production begins with hydrolysis of dichloromethylsilane (DCMS), as raw material, which continues through condensation polymerization. Previous research reported the synthesis of PMHS using an acid solvent with different temperature variations and indicated that low-viscosity PMHS can be produced through condensation at 15–20 °C. However, this process requires a very long polymerization time. Meanwhile, synthesis using a higher temperature of 50 °C required a catalyst. The influence of solvents, one of the important synthesis temperatures, on the synthesis process of PMHS has not been explored. Furthermore, the toxicity of this material has not been reported. In this study, PMHS with low- and medium-viscosity were synthesized from DCMS with different solvents and additional control of the condensation temperature to accelerate the polymerization. Utilizing a basic diethyl ether (DE) solvent facilitates a higher viscosity value than an acidic dichloromethane (DCM) solvent. All PMHS samples were characterized by a viscometer, refractometer, surfgauge, UV–Vis, FTIR, and NMR spectroscopy. The in vitro hen’s egg chorioallantoic membrane (HET-CAM) toxicity test of PMHS was also conducted. A low-viscosity PMHS sample had a surface tension of 20 milliN/m and a refractive index of 1.3960, while medium-viscosity had 21 milliN/m and 1.3982. All samples were ~ 100% transparent, had typical functional groups of PMHS, and did not show signs of being irritant (non-toxic). Therefore, PMHS has the potential to be developed as a new material for vitreous humour substitution.

The well-defined piano-stool iron(II) complex (Cp-NHC)Fe(CO)I bearing a bidentate cyclopentadienyl-functionalised N -heterocyclic carbene ligand is shown to catalyse the reduction of ketones under mild conditions (1–2 h at room temperature) when combined with catalytic amounts of potassium tert -butoxide, and using Ph 2 SiH 2 and the inexpensive and less reactive polymethylhydrosiloxane as reducing agents. The stoichiometric reaction of (Cp-NHC)Fe(CO)I with potassium tert -butoxide generates an iron-hydroxo complex, which seems to be the active species in the reduction of ketones. Graphical Abstract

Hybrid materials based on tetraethoxysilane (TEOS) and polymethylhydrosiloxane (PMHS) have been prepared employing sol–gel synthesis pathway, and the effects of preparation parameters such as PMHS concentration, water and NaOH amount on the structural characteristics were detailed investigated based on various techniques. It is illustrated that structural characteristics especially pore size can be tuned readily by adjusting the amount of PMHS during the sol–gel reaction. Furthermore, pore size increases with water amount and contrarily is almost independent on the amount of sodium hydroxide (NaOH) added in the sol–gel process. Typical hybrid sample prepared with desirable preparation parameters presents disordered wormhole structure with uniform mesopores, developed porosity with high specific surface area and pore volume and stable framework. In virtue of facileness and tunable composition, this synthesis pathway can be favorably applied for the preparation of other fascinating materials, i.e. porous ceramics, hydrophobic coatings and aerogels as well.