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Eugenol-containing oligoorganosilsesquioxanes were synthesized by the method of hydrolytic polycondensation in an active medium under various reaction conditions. The obtained products were characterized by 29Si NMR spectroscopy and MALDI-TOF spectrometry. It was shown that factors such as the reaction temperature, polycondensation duration, and molar ratio between the initial alkoxysilane monomer and acetic acid may affect the molecular weight characteristics and molecular structure of the formed oligomer, like the content of stressed cyclic units (T3, DTT, TDT) and unstressed silsesquioxane units TnDm. In particular, an increase in the ratio of the initial reagents led to an increase in the content of silsesquioxane Tn fragments from 28.2%mol to 41.7%mol, while the number of strained cyclic structures decreased by more than two times. An increase in the synthesis time is of no particular practical value since it was found that the composition of the oligomers synthesized for 6 h and 12 h was practically identical, as was that of the oligomers synthesized for 24 h and 48 h. A noticeable transition in the oligomer composition was observed only when the synthesis time was changed from 12 h to 24 h. Finally, it was shown that the choice of synthesis temperature had the strongest effect on the oligomer composition. The oligomer synthesized at 95 °C contained the highest amount of silsesquioxane Tn fragments, >77%mol, while a Tn fragment content of ~42%mol was observed during the synthesis at 117 °C. It was shown that silsesquioxanes are devitrified at room temperature (Tg from −6.4 to −10.6 °C), and their thermal stability in an inert atmosphere is 300 °C. The synthesized oligomers, due to the presence of hydroxyl-containing eugenol units, may be promising binders and additives for functional epoxy–silicone paints and coating materials. [ABSTRACT FROM AUTHOR]

The deoxygenation process in water used in well injection operations is an important matter to eliminate corrosion in the petroleum industry. This study used molecular dynamics simulations to understand the behavior of siloxane surfaces by studying the surface properties with two functional groups attached to the end of siloxane and their effect on the deoxygenation process. The simulations were performed using LAMMPS to characterize surface properties. Jmol software version 14 was used to generate siloxane chains with (8, 20, and 35) repeat units. We evaluated properties such as total energy, surface tension, and viscosity. Then, we used siloxane as a membrane to compare the efficiency of deoxygenation for both types of functional groups. The results indicated that longer chain lengths increased the total energy and viscosity while decreasing surface tension. Replacing methyl groups with trifluoromethyl (CF3) groups increased all the above mentioned properties in varying proportions. Trifluoromethyl (CF3) groups showed better removal efficiency than methyl (CH3) groups but allowed more water to pass. Furthermore, the simulations were run using the class II potential developed by Sun, Rigby, and others within an explicit-atom (EA) model. This force field is universally applicable to the atomistic simulation of polymers, inorganic small molecules, and common organic molecules. [ABSTRACT FROM AUTHOR]

Organo(chloro)silanes are essential chemicals, but the synthesis of compounds of the formula RnSiCl4−n with defined values of n is usually laborious. Herein, we first disclose that a [4+2]‐cycloaddition between readily available Cl3SiC≡CSiCl3 and selected dienes provides facile access to vicinal bis(trichlorosilylated) benzenes and bicyclo[2.2.2]octa‐2,5‐dienes. Second, we show how the number of six Si−Cl bonds in 1,2‐(Cl3Si)2C6H2Me2 (1) can be selectively reduced to four or two by reaction with pinacol (H2pin) or catechol (H2cat), which act as Si⋅⋅⋅Si’‐bridging and/or Si‐chelating ligands. Third, we demonstrate that the thermolysis of compound 6, which contains a benzannulated eight‐membered C2(SiCl2)2(μ‐pin) ring with Si⋅⋅⋅Si’‐bridging pin moiety, furnishes 13 with a benzannulated five‐membered C2(SiCl2)2O ring via the release of pinacolone. Such cyclic disiloxanes are valuable building blocks for specialty silicones; an alternative assembly of the Si−O−Si unit by controlled hydrolysis of 1 is not feasible if the four valuable Si−Cl functionalities are to be retained for further derivatization. Substitution of one Cl atom per Si site of 13 gives the rac‐1,3‐disila‐2‐oxaindane rac‐15 with high selectivity. [ABSTRACT FROM AUTHOR]

The erosion phenomena of the natural stone in cultural heritage are induced by various sources. Consequently, the development of multifunctional protective materials that combine two or more useful properties is an effective strategy in addressing the synergistic effects of various erosion mechanisms. A multifunctional coating, consisting of a silane-based precursor and zinc oxide (ZnO) nanoparticles (NPs), is produced and tested for the protection of limestone. The hybrid coating combines the following three properties: superhydrophobicity, including water-repellency, photocatalytic self-cleaning and biocidal activity. The relative concentration of the NPs (0.8% w/w), used for the suggested composite coating, is carefully selected according to wetting studies, colourimetric measurements and durability (tape peeling) tests. The non-wetting state is evidenced on the surface of the composite coating by the large contact angle of water drops (≈153°) and the small contact angle hysteresis (≈5°), which gives rise to a physical self-cleaning scenario (lotus effect). The photocatalytic chemical self-cleaning is shown with the removal of methylene blue, induced by UV-A radiation. Moreover, it is shown that the suggested coating hinders the incubation of E. coli and S. aureus, as the inhibitions are 94.8 and 99.9%, respectively. Finally, preliminary studies reveal the chemical stability of the suggested coating. [ABSTRACT FROM AUTHOR]

Copyright of Silicone Material is the property of Silicone Material Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Legal requirements for refrigerants necessitate a continuous development of these fluids, also focusing on mixtures. This article contributes three aspects to the ongoing research: (1) Experimental mean heat transfer coefficients were determined for the condensation of two novel zeotropic mixtures, hexamethyldisiloxane (MM)/octamethyltrisiloxane and ethanol/MM, gathered for filmwise condensation on a vertical tube. (2) Both mixtures were investigated with several compositions to provide a comprehensive understanding of the mixture effects. (3) The results were taken to develop a novel superposition approach to predict mixture condensation. [ABSTRACT FROM AUTHOR]

Mankind has erected monoliths and stone structures for millennia to ensure stories and culture are passed on to future generations. In the modern era, monuments and architecture are designed with the intention of lasting several decades to hundreds of years and may utilize an arrangement of natural and synthetic materials. Choice of substrate helps ensure the longevity of these structures, but coatings are utilized to provide additional characteristics and subsequent protection to the finished product. Protective coatings come in a variety of base materials and are utilized to address specific degradation concerns. Advances in this field focus on protection of the surface while preventing any unintended damage to the substrate. This mini review summarizes the advances in protective coatings useful for historical monuments and architecture up to January 2024. © 2024 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

The reactive diluent prepared by siloxane modified Trimethylene oxide can improve the performance of the UV curing system. Therefore, 1,7-bis [(3-ethyl-3-methoxyoxacylobutane) propyl] octadecylosiloxane (BEMOPOMTS) was synthesized from diethyl carbonate, trimethylopropanes, allyl bromide, and 1,1,3,3,5,5,7,7-octadecylosiloxane as the main raw materials. BEMOPOMTS can be used as reactive diluents in the field of cationic UV curing. It has good thermal stability, and the addition of BEMOPOMTS significantly improves the tensile strength and elongation at break of epoxy resin. Compared with the pure epoxy resin, adding 20% BEMOPOMTS increased the elastic modulus by 25% to 677 MPa. [ABSTRACT FROM AUTHOR]

The waterways adjacent to Washington DC, USA have a history of contamination from heavy metals, nutrients, pesticides, and industrial chemicals. Among the chemicals of concern are PAHs, which are a historical contaminant but also have modern pyrogenic and petrogenic sources in the area's waterways. Another group of contaminants that are of emerging interest are siloxanes (silicones), which are widely used as lubricants, sealants, and cosmetics. Some lower-molecular-weight siloxanes are regulated by the EU in recognition of harm to aquatic life, but there are no restrictions in the United States. In fact, studies examining water pollutants do not typically test for siloxanes. Here, we present the concentrations of specific PAHs and siloxanes from surface sediments in the Potomac and Anacostia Rivers (including the Anacostia's tributaries) collected between 2018 and 2023. Both D5 (decamethylcyclopentasiloxane) and D6 (dodecamethylcyclohexasiloxane) were found in most locations, with concentrations averaging 0.13 and 0.006 mg/g (dry mass), respectively. Pyrene, fluoranthene, bibenzyl, and phenanthrene were also found in the Anacostia and some of its tributaries, with concentrations increasing downstream. In the Potomac, concentrations were generally lower than those observed in the Anacostia. Based on ratios of pyrene to fluoranthene + pyrene, the likely source of PAHs was petrogenic. [ABSTRACT FROM AUTHOR]

Oligomeric models of linear ladder silanes, siloxanes and siloxazanes with seven repeat units consisting of four-, six-, or eight-membered rings were designed and their conformations in chloroform were explored. The Low Mode–Monte Carlo conformational method was used to explore oligomeric flexibility on the OPLS-2005/GBSA(CHCl3) potential energy surface to obtain a set of low energy structures for each oligomer. These structures were then optimized using B3LYP/6-31G*/SCRF-PBF(CHCl3) calculations. The results indicate complex conformational dynamics with mostly non-planar, curved structures. Electron delocalization from the lone pair of electrons on N or O into empty 3d orbitals on Si was not observed. [ABSTRACT FROM AUTHOR]

We have synthesized the siloxane-grafted polyurethane copolymers aqueous dispersions by semi-continuous emulsion polymerization. The mono-methacryloxypropyl terminated polydimethylsiloxane was used to react with the acrylate-terminated waterborne polyurethane, which served as seed emulsions. It is obtained that the as-synthesized copolymer dispersions are stable and have small particle sizes ranging from 77 nm to 120 nm, and they possess core-shell structures. Moreover, the results show that the prepared films exhibit high transparency and hydrophobic surface. Moreover, the enrichment of siloxane and the heterogeneous structure on the film surface was studied. The results of Raman spectra disclose that the intensities of siloxane on the surface change over time during the film formation. These results are correlated to the pressure difference of droplets and low surface tension of siloxane segments. The as-synthesized dispersions promise to be applied in the displayer coatings. [ABSTRACT FROM AUTHOR]

To mitigate the environmental hazards aroused by fossil-based lubricants, the development of eco-friendly internal lubricants is imperative. Siloxane-based internal lubricants, widely applied as plasticizers in polymeric compounds, are a promising option. However, their impacts on the tribological properties of polymeric tribocomponents are still unclarified. Therefore, in the current study, a siloxane-based internal lubricant with the product name 'EverGlide MB 1550 (EG)' was dispersed into a polybutylene terephthalate (PBT)-based tribological composite to investigate whether the tribological properties of the composite can be optimized. A block-on-ring (BOR) test configuration was used for this purpose. It was found that the addition of EG to the composite significantly improved the tribological behavior; the improvement was particularly significant under lower load conditions (pv-product ≤ 2 MPa∙m/s). Compared to the reference PBT composite, the addition of EG reduced the friction coefficient (COF) by about 30% and the specific wear rate by about 14%. An accompanying surface analytical investigation using photoelectron spectroscopy to elucidate the effective mechanisms at the molecular level showed the availability of tribologically effective and free EG after its addition to the composite in the relevant tribocontact. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different alkali catalysts (K2CO3, KOH, NaOH, and Na2CO3) on the yield and composition of biocrude oil and aqueous products obtained from hydrothermal liquefaction (HTL) of corn stover. HTL was performed in a laboratory-scale tubular reactor at 320 °C for 90 min and catalyst loading of 5.0 and 7.5 % (by weight of biomass). The composition of the biocrude oil and aqueous products was determined using GC-MS. Results revealed that hydroxide catalysts are more effective than carbonate catalysts in increasing biocrude oil yield. Notably, NaOH achieved a high conversion rate of 92–94 % daf (dry and ash-free basis), significantly surpassing the uncatalyzed HTL (69.4 % daf). The highest biocrude oil yield of 22.12–22.57 % daf was obtained using KOH. Si-containing compounds (e.g., silanes and siloxanes) were identified as the most abundant components in the biocrude oil, suggesting potential for further exploration in producing platform chemicals from these compounds.

According to the published articles, the capacity and output of silicone methyl monomer, the import and export of primary polysiloxane, the revenue of listed enterprises in silicone, the new projects, the formulation of policies in silicone in 2023 were summarized, and the R&D in silicone (including R&D investment of enterprises, self-developed projects of enterprises and R&D priorities in silicones) was also introduced. [ABSTRACT FROM AUTHOR]

Dyes derived from benzothiazoles are an important class of heterocycles which have remarkable photophysical properties. New photoluminescent 2-phenylbenzothiazole derivatives containing different functional groups were synthesized in high yields and used for silylated derivatives synthesis. The new photoactive compounds were fully characterized and their photophysical properties were investigated. The absorption and fluorescence spectra of the benzothiazoles and their silylated derivatives were evaluated in a series of organic solvents. The results showed that the benzothiazoles present absorption in the ultraviolet range and emission in the blue region with moderate quantum yields and large Stokes shift. The solvatochromism of these compounds was investigated by using Lippert and ET(30) Dimroth-Reichardt empirical solvent polarity scales. The dipole moments obtained by Bakshiev and Kawaski-Chamma-Viallet equations revealed that the excited states were more polar than the ground states. [ABSTRACT FROM AUTHOR]

Three liquid crystalline monomers were systematically designed, synthesised and characterised. Methyl methacrylic unit was linked to the mesogenic compound, 4′-Undecycloxybiphenyl-4-yl 4-octyloxy-2-(pent-4-en-1-yloxy) benzoate, (Me), using disiloxane, ester and siloxane units respectively. In the first compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-(3-(4-(methacryloyloxy)butyl)-1,1,3,3-tetramethyldisiloxanyl)pentyl)oxy)-4-(octyloxy)benzoate, (M1), the methyl methacrylic unit was linked to the mesogen by disiloxane group, (Si–O–Si), while ester group, (COOC), was used in the second compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-(methacryloyloxy)pentyl)oxy)-4-(octyloxy)benzoate, (M2), and siloxane unit, (Si–O), in the third compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-((4-(methacryloyloxy)butyl)dimethylsilyl)pentyl)oxy)-4-(octyloxy)benzoate, (M3). The introduction of the methyl methacrylic unit caused the melting point of the compounds to reduce with Me melting at 53.3 °C, M1 at −8.1 °C and M2 at −12.5 °C. The three compounds showed characteristic nematic textures when observed under POM and when compared to the mesogenic compound (Me, 71.7 °C), there were remarkable reduction in the clearing points of the compounds, with M1 clearing at 18.6 °C, M2 at 68.8 °C and M3 at 10.3 °C. Finally, there was appreciable increment in the nematic phase range for the compounds when compared to the mesogen, Me, 18.4 °C. The range was 26.7 °C for M1, 81.3 °C for M2 and since there was no observable crystallization point for M3, the range was not determined. [ABSTRACT FROM AUTHOR]

The title compound, [Fe(C4H8O)4(H2O)2][Fe4Ga4(C2H6O2Si)Cl4(CO)15]·4C4H8O, consists of an iron(II) cation octahedrally coordinated by two water molecules (trans) with four tetrahydrofurans (THF) at equatorial sites. Two additional THF molecules are hydrogen bonded to each of the water molecules. The dianion of the title compound is an organometallic butterfly complex with a dimethyl siloxane core and two iron-gallium fragments. The lengths of the iron to gallium metal–metal bonds range from 2.3875 (6) to 2.4912 (6) Å.

Eugenol-containing oligoorganosilsesquioxanes were synthesized by the method of hydrolytic polycondensation in an active medium under various reaction conditions. The obtained products were characterized by 29Si NMR spectroscopy and MALDI-TOF spectrometry. It was shown that factors such as the reaction temperature, polycondensation duration, and molar ratio between the initial alkoxysilane monomer and acetic acid may affect the molecular weight characteristics and molecular structure of the formed oligomer, like the content of stressed cyclic units (T3, DTT, TDT) and unstressed silsesquioxane units TnDm. In particular, an increase in the ratio of the initial reagents led to an increase in the content of silsesquioxane Tn fragments from 28.2%mol to 41.7%mol, while the number of strained cyclic structures decreased by more than two times. An increase in the synthesis time is of no particular practical value since it was found that the composition of the oligomers synthesized for 6 h and 12 h was practically identical, as was that of the oligomers synthesized for 24 h and 48 h. A noticeable transition in the oligomer composition was observed only when the synthesis time was changed from 12 h to 24 h. Finally, it was shown that the choice of synthesis temperature had the strongest effect on the oligomer composition. The oligomer synthesized at 95 °C contained the highest amount of silsesquioxane Tn fragments, >77%mol, while a Tn fragment content of ~42%mol was observed during the synthesis at 117 °C. It was shown that silsesquioxanes are devitrified at room temperature (Tg from −6.4 to −10.6 °C), and their thermal stability in an inert atmosphere is 300 °C. The synthesized oligomers, due to the presence of hydroxyl-containing eugenol units, may be promising binders and additives for functional epoxy–silicone paints and coating materials.

The fabrication of hydrophobic graphite-siloxane composite coating on low carbon steel (LCS) substrate using electrophoretic deposition is reported. At a critical concentration (~ 20 wt. %) of methyl hydrogen polysiloxane (trade name KF-99), it achieved the highest hydrophobicity of the composite coating (Contact angle ~122°). The corrosion resistance of the hydrophobic composite coating is examined in 3.5 wt--% NaCl solution. The potentiodynamic curves demonstrate that the corrosion rate is drastically reduced to 79.3 % for graphite-siloxane composite coating (cured at 400 °C) than bare LCS substrate. Both grain refinement due to heat treatment and increment in water contact angle significantly contribute to increased corrosion resistance. Additionally, it is observed that graphite-siloxane composite coating shows good antibacterial properties, which may enable the coating to combat microbial corrosion of metals. To support the experimental findings, we have studied the interactions of water molecules on low-carbon steel and the hybrid structure of LCS/graphite and tri-layer LCS/graphite/siloxane using sophisticated Density Functional Theory simulations. The adsorption energy data reflect that water strongly interacts with LCS, but interactions become weak with LCS/graphite and hydrophobic for LCS/graphite/siloxane, supporting the experimental data. There is a reduced interaction between the O 2p orbital of H2O with LCS with the addition of graphite, which further shows a drastic reduction with siloxane. The low H2O adsorption energy and reduced charge transfer from H2O to LCS in the presence of graphite-siloxane composites can confirm this. [ABSTRACT FROM AUTHOR]

This work presents the synthesis of the new bent-core polymers with siloxane units connected to the one side of azobenzene units. The structure of siloxane-based azobenzene bent-core polymers, 7a–c, was elucidated by spectral analysis (nuclear magnetic resonance and Fourier-transform infrared spectroscopy). The results of gel permeation chromatography suggested that all polymers (7a–c) showed polydisperse (polydispersity index >1). Besides, the extent of polymerization in the following order: 7a > 7b > 7c, where the degree of polymerization values were 7, 8 and 11, respectively. Polarizing optical microscopy revealed that the bent-core liquid crystal (BCLC) monomers, 6a and 6b, displayed the smectic A phase, whereas BCLC monomer 6c and all siloxane-based main-chain polymers (MCPs) (7a–c) were crystalline in nature. The result of ultraviolet-visible spectroscopy demonstrated that all MCPs (7a–c) exhibited strong photoisomerization behavior in solution. All polymers (7a–c) showed trans to cis isomerization in about 200 s, whereas the reverse process required much longer times ranging from 400 to 520 min in solution. The photo-switching study on azobenzene containing polymers stated that the effect of alkyl chain length and type of central core units on trans to cis isomerization were negligible. In contrast, both parameters influence the cis to trans process in which the photo-switching behavior of these materials may be primarily suitably exploited in the field of photo-induced phenomenon. Time dependence photoisomerization curve of a) trans isomer (7a–c) showing the effect of UV illumination at 365 nm wavelength, which take time for trans to cis isomerization in about 200s, and b) cis isomer (7a–c) showing the thermal back relaxation time, the reverse process required much longer times ranging from 400–520 min in solution [ABSTRACT FROM AUTHOR]

Low Coulombic efficiency and significant capacity decay resulting from an unstable solid electrolyte interphase (SEI) and dendritic growth pose challenges to the practical application of lithium‐metal batteries. In this study, a highly efficient protection layer induced by octaphenylsilsesquioxane (OPS) with LiFSI salt is investigated. The OPS exhibits a strong adsorption energy with lithium, its multi‐site gradient adsorption ability enables the simultaneous capture of 8 Li+ and the uniform regulation of Li ion flux. Moreover, the mechanical strength and electronic insulation of the OPS layer induces Li deposition under the protection layer and effectively inhibits lithium dendrite growth. Such a protection layer contributes to the stable and dendrite‐free performance of a lithium‐metal battery employing LiNi0.8Co0.1Mn0.1O2 (NCM811) as a cathode and an ultrathin OPS‐protected lithium foil (20 µm) as the anode. A remarkable capacity retention of 91.4% is achieved after 300 cycles at 1C. The OPS‐protected Li anodes and NCM811 are also tested in combination with a Li1.5Al0.5Ge1.5(PO4)3 solid electrolyte, showing extended cyclability up to 300 cycles with an average Coulombic efficiency of 99.58% and capacity retention of 85.7%. [ABSTRACT FROM AUTHOR]

In the course of this research, we successfully created three series of liquid crystalline compounds featuring the trans-cyclohexane structure. One series of compounds featured a double bond at the terminal position of the molecules, whereas the remaining two series incorporated disiloxane and trisiloxane groups. Each series comprised five spacers of different lengths, specifically 3, 4, 5, 6, and 11 methylene units. We identified the structures of the synthesized compounds using Nuclear Magnetic Resonance spectroscopy and characterized their liquid crystalline behavior through thermal analysis and polarized optical microscopy. The results revealed that both the length of the spacer and the presence of siloxane groups significantly influenced the liquid crystal phase transitions, transition temperatures, and temperature ranges. These findings provide valuable insights for designing and developing new liquid crystal materials with tailored properties for various applications. [ABSTRACT FROM AUTHOR]

In this study, chitosan was modified by two kinds of different siloxanes, γ-glycidoxypropyl-trimethoxysilane (GPTMS) and γ-glycidoxypropyl-dimethoxy- methylsilane (GPDMS), respectively, then applied for anti-pilling of cashmere knitted fabrics. The structure of the modified chitosan, the apparent morphology and the mechanical properties of the modified film were analyzed by FTIR, SEM and DMA, respectively. The hydrophilicity and swelling properties of the modified film were compared. The results showed that epoxy groups of siloxane reacted with amino groups of chitosan, and the –OR (R represents alkyl) groups of siloxane hydrolyzed and polycondensation conducted during the film-forming process. After modification, the mechanical properties of the film were more flexible, the hydrophilicity and swelling of the film was decreased. Cashmere knitted fabric was treated with the modified chitosan and glutathione was chosen as the model compound to explore the reaction between modified chitosan and cashmere fibers. The apparent morphology and elements distribution of the fibers were observed by SEM and EDS, respectively. The directional friction effect of the fibers was tested by fiber friction coefficient tester. The pilling grade, handle, whiteness and launderability of fabric were investigated. The results showed that the epoxy groups remaining in siloxane were reacted with the amino groups of cashmere fiber, which enhance the binding of the fiber and siloxane-modified chitosan, the siloxane-modified chitosan film formed on fibers in situ. The directional friction effect of the fiber significantly reduced, the tendency of fuzzes to the surface of the fabric was weakened and the probability of tangling of exposed fuzzings was reduced, the pilling grade of the fabric treated by modified chitosan reached level 4 and the fabrics had good launderability, the soft and smooth handle was still preserved. There was no obvious color difference of cashmere fabrics treated with siloxane-modified chitosan. [ABSTRACT FROM AUTHOR]

The pollution of soil by heavy metals becomes a prime ecological problem. Recultivation of polluted soil objects is usually made by means of different types of sorbents. So, in this connection the search for the most effective and multifunctional sorbing agent is relevant. The model experiment of soil pollution by several heavy metals in upper soil horizon was carried out. The soil for that research was Grey-Luvic Phaeozems. Lead (Pb2+) and copper (Cu2+) were chosen as pollutants. Solutions of lead acetate (Pb(CH₃COO)₂·3H2O) and copper sulphate (CuSO₄·7Н2O) of three different concentrations (1 MPC, 5 MPC, 10 MPC) were used as pollutants. Solutions of organosilicon adsorbent – 1,1,3,3,3-tetrahydroxy-1,3-dimethyldisiloxane polyhydrate (PMSPG) were also applied in three different variants: 0.01%; 0.1%; 1%. The mobile forms of heavy metals were researched by method of atomic absorption spectrometry. The mobile forms of heavy metals were extracted by the ammonium acetate buffer (pH = 4.8). According to results, the application of organosilicon sorbent had a positive issue. Application of adsorbent significantly reduced the concentrations of mobile heavy metal compounds. The application of PMSPG solution with concentration of 1% was the most effective. A vegetation experiment was carried out. Cress (Lepidium sativum L.) of “Zabava” variety was used as a test-crop. Favourable changes in the growth of cress with the use of adsorbent at the concentration of 1% compared to the control variants were revealed.

The deoxygenation process in water used in well injection operations is an important matter to eliminate corrosion in the petroleum industry. This study used molecular dynamics simulations to understand the behavior of siloxane surfaces by studying the surface properties with two functional groups attached to the end of siloxane and their effect on the deoxygenation process. The simulations were performed using LAMMPS to characterize surface properties. Jmol software version 14 was used to generate siloxane chains with (8, 20, and 35) repeat units. We evaluated properties such as total energy, surface tension, and viscosity. Then, we used siloxane as a membrane to compare the efficiency of deoxygenation for both types of functional groups. The results indicated that longer chain lengths increased the total energy and viscosity while decreasing surface tension. Replacing methyl groups with trifluoromethyl (CF3) groups increased all the above mentioned properties in varying proportions. Trifluoromethyl (CF3) groups showed better removal efficiency than methyl (CH3) groups but allowed more water to pass. Furthermore, the simulations were run using the class II potential developed by Sun, Rigby, and others within an explicit-atom (EA) model. This force field is universally applicable to the atomistic simulation of polymers, inorganic small molecules, and common organic molecules.

The waterways adjacent to Washington DC, USA have a history of contamination from heavy metals, nutrients, pesticides, and industrial chemicals. Among the chemicals of concern are PAHs, which are a historical contaminant but also have modern pyrogenic and petrogenic sources in the area’s waterways. Another group of contaminants that are of emerging interest are siloxanes (silicones), which are widely used as lubricants, sealants, and cosmetics. Some lower-molecular-weight siloxanes are regulated by the EU in recognition of harm to aquatic life, but there are no restrictions in the United States. In fact, studies examining water pollutants do not typically test for siloxanes. Here, we present the concentrations of specific PAHs and siloxanes from surface sediments in the Potomac and Anacostia Rivers (including the Anacostia’s tributaries) collected between 2018 and 2023. Both D5 (decamethylcyclopentasiloxane) and D6 (dodecamethylcyclohexasiloxane) were found in most locations, with concentrations averaging 0.13 and 0.006 mg/g (dry mass), respectively. Pyrene, fluoranthene, bibenzyl, and phenanthrene were also found in the Anacostia and some of its tributaries, with concentrations increasing downstream. In the Potomac, concentrations were generally lower than those observed in the Anacostia. Based on ratios of pyrene to fluoranthene + pyrene, the likely source of PAHs was petrogenic.

Siloxanes, widely used in various consumer and industrial products, are emerging concerns of contaminants. Despite this, limited studies have been conducted on contamination and time trends on siloxanes in coastal environments. In the present study, four cyclic and 15 linear siloxanes were measured in sediments collected from an artificial saltwater lake in Korea during 2001–2016 to investigate contamination, time trends, and ecotoxicological concerns. Cyclic siloxanes were detected in all sediment samples, whereas linear siloxanes were not frequently detected. The highest siloxane concentrations were observed in creeks passing through various industrial complexes, indicating that industrial activities predominantly contributed to siloxane contamination in coastal environments. Decamethylcyclopentasiloxane (D5) and dodecylcyclohexasiloxane (D6) were predominant siloxanes in sediments over the last two decades. Siloxane concentrations significantly increased in creek sediments from 2008 to 2016, whereas those in inshore and offshore regions significantly decreased due to a strong dilution effect by the operation of tidal power plant. This suggests that consumption patterns and coastal development activities are crucial factors determining the contamination and time trends in the sedimentary siloxanes. The sedimentary concentrations of octamethylcyclotetrasiloxane (D4) and D5 exceeded several thresholds, raising the potentials for ecological risks to aquatic organisms.

Novel phenolic resin/silicone aerogels (PR-Si) were prepared through a facile sol-gel polymerization and ambient pressure drying process without solvent exchange. Without the addition of an additional catalyst, the hydroxyl condensation reaction between the siloxane oligomer and the phenolic resin resulted in the silicon being incorporated into the PR. The obtained aerogels exhibited high compressive strength (0.84–21.11 MPa) and low thermal conductivities [0.046–0.077 W/(m·K)]. The introduction of a Si–O network structure in the PR effectively improved the mechanical properties and thermal stability of aerogels. It is clear from the TGA plot that the mass loss temperature of the PR-Si aerogel was increased by 73 and 79 °C for the weight loss temperatures of 5 and 10% compared to cured pure PR. [ABSTRACT FROM AUTHOR]

Flexible poly (imide siloxane) block copolymer (which was not adhesive feature) was exposed to gamma radiation at 10 kGy by using a certified Co-60 radioisotope for the evaluation of its optimum application condition in gamma irradiation fields with high dose. High gamma dose application has caused to display tuneable high-temperature features as the result of its density development due to radiation hardness effect at 10 kGy. The development of the polysilicon-11 crystallites has caused a decrease in the penetration of gamma photons at the irradiated flexible copolymer due to the gamma absorbed dose. The elimination of the agglomeration by high gamma dose application has assisted the development of the grainy surface at the irradiated flexible copolymer with a more homogeneous structure. The development of the gamma shielding performance of the irradiated polymer has explained the optimum synthesis conditions for the solution of the gamma dose problems at high-temperature applications in contact with the contoured surface (including different heights, depths curvatures on the surface and presenting importance in radiation shielding design and engineering) at high gamma dose areas. A comparison of penetration deepness of gamma photons has indicated its performance (at 0.662 MeV by using the Cs-137 radioisotope and at 1.25 MeV by using the Co-60 radioisotope by using the gamma transmission technique) to determine the details about the density variations of this polymer. The hybrid copolymer was improved to support the development of polymeric instruments for new trend applications in computing and artificial intelligence, biotechnology, and internet of things (for smart monitoring and sensing technology). [ABSTRACT FROM AUTHOR]

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Addressing the issues of poor interlaminar adhesion and complicated preparation process in traditional unidirectional water transport fabric, hydrophilic channels were successfully constructed on the surface of the knitted fabric by pattern screen printed technology, resulting in a directional water transport fabric with high air permeability and moisture permeability. Herein, scanning electron microscopy, X-ray spectroscopy, Fourier infrared spectrometer, contact angle tester, moisture permeability meter, air permeability meter, and moisture management meter were used to analyze the morphology, element distribution, chemical structure, hydrophilicity, and wearing comfort properties of fabric. Besides, the printing process was optimized to improve the properties of the fabric. The results show that the ideal pattern printed fabric with a 90% hydrophobic area was successfully prepared under the printing pressure of 30 Hz. The resulting fabric exhibited an air permeability of 104 mm/s, a water vapor transmission of 289 g • m-2 • h-1, and a one-way transport capability of 588% > making it suitable for a variety of applications. [ABSTRACT FROM AUTHOR]

In this study, siloxane has been used for the protection of metal artifacts from corrosion in the form of transparent barrier coating films because of their good adhesion to the metal substrate. The effect of oxygen plasma pre-treatment on the adhesion properties of the siloxane thin film on the silver-copper alloy substrate was investigated. Radiofrequency plasma-enhanced chemical vapor deposition (RF-PECVD) was used for the deposition process. Surface identification and characterization of the deposited films were carried out using Scanning Electron Microscopy coupled with energy-dispersive x-ray spectroscopy (SEM–EDX) and Fourier-transform infrared spectroscopy (FT-IR). Surface topography and roughness were investigated by atomic force microscopy (AFM). The hydrophobic characteristic was measured by water contact angle measurement (WCA). The film thickness was evaluated using a spectroscopic ellipsometer (SE). Colorimetric measurement (CM) was used to evaluate changes in the appearance of the surface following the PECVD deposition of the SiO2 protective layer. The corrosion protection ability of siloxane films for metal substrates as a function of RF power and gas feed composition was examined by the electrochemical impedance spectroscopy (EIS) technique. It was found that the deposited film improved the protective efficiency for samples from 55.29 to 92.93%. Besides, after the oxygen plasma pretreatment step, the film showed better corrosion resistance of the tested samples. [ABSTRACT FROM AUTHOR]

Hemihydrate phosphogypsum, an industrial solid waste product of phosphoric acid production, is abundant and inexpensive. If the problem of poor water resistance is solved, this material could be substituted for cement and other traditional energy-consuming cementitious materials in the construction industry. This approach would confer important economic and environmental benefits while promoting the resource utilization of phosphogypsum (PG). In this study, hydrophobic and self-cleaning coatings of H-PDMS/PMHS/OTS hybrid nanosilica were prepared on a post-hydroxylated PG surface using sol–gel and impregnation methods. The water contact angle, Fourier-transform infrared spectroscopy, Three-dimensional surface morphology and roughness analysis, X-ray photoelectron spectroscopy, scanning electron microscopy, surface abrasion tests, and tape adhesion tests were used to evaluate the hydrophobicity of the coatings. The results demonstrated that the in situ reaction produced a hydrophobic siloxane/nanosilica hybrid network that bonded to the PG surface via hydrogen bonding, making the otherwise completely hydrophilic PG hydrophobic (PGH-3, contact angle (CA) = 144.1°). The PGH-3 sample exhibited excellent chemical stability, maintaining a contact angle greater than 135° under strongly acidic or alkaline conditions. The contact angle remained at 123.7° after 50 tape-bonding tests. After 100 wear cycles, the contact angle remained at 121.9°. This study presents an environmentally friendly method and a straightforward application procedure to impart hydrophobicity to solid waste PG. Its potential is thus demonstrated in the field of PG-based construction materials and the comprehensive utilization of solid waste. [ABSTRACT FROM AUTHOR]

To mitigate the environmental hazards aroused by fossil-based lubricants, the development of eco-friendly internal lubricants is imperative. Siloxane-based internal lubricants, widely applied as plasticizers in polymeric compounds, are a promising option. However, their impacts on the tribological properties of polymeric tribocomponents are still unclarified. Therefore, in the current study, a siloxane-based internal lubricant with the product name ‘EverGlide MB 1550 (EG)’ was dispersed into a polybutylene terephthalate (PBT)-based tribological composite to investigate whether the tribological properties of the composite can be optimized. A block-on-ring (BOR) test configuration was used for this purpose. It was found that the addition of EG to the composite significantly improved the tribological behavior; the improvement was particularly significant under lower load conditions (pv-product ≤ 2 MPa∙m/s). Compared to the reference PBT composite, the addition of EG reduced the friction coefficient (COF) by about 30% and the specific wear rate by about 14%. An accompanying surface analytical investigation using photoelectron spectroscopy to elucidate the effective mechanisms at the molecular level showed the availability of tribologically effective and free EG after its addition to the composite in the relevant tribocontact.

Cage-type silicate with a double six-ring (D6R) structure is successfully functionalized with dimethylsilyl and dimethylsilanol groups. The dimethylsilanol-functionalized cages are assembled to form a 1D structure through intermolecular hydrogen bonding of the silanol groups between the cages. These results will contribute to the development of a building-block approach for the creation of ordered siloxane-based nanomaterials. [ABSTRACT FROM AUTHOR]

Siloxanes and synthetic musk compounds (SMCs) have been widely used as additives in household and personal care products. Humans are easily exposed to siloxanes and SMCs originating from these products through ingestion and dermal absorption of indoor dust. In the present study, indoor dust samples were analyzed for 19 siloxanes (cyclic and linear) and 12 SMCs (polycyclic, macrocyclic, and nitro musks) to assess their occurrence, time trends over time, source, and health risks. A total of 18 siloxanes and 10 SMCs were detected in all indoor dust samples obtained from 2011⎯2021, indicating widespread and long-term contamination. Higher detection frequencies and concentrations were associated with siloxanes and SMCs with higher use and strong resistance against degradation processes. Indoor dust samples were dominated by linear siloxanes (L11–L13), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB), musk ketone (MK), and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN). The frequent use of household and personal care products is likely an important source of siloxane and SMC contamination in indoor environments. The concentrations of siloxanes and SMCs in indoor dust increased from 2011 to 2021, particularly, those of linear siloxanes, reflecting the impact of regulatory actions addressing cyclic siloxanes. The profiles of siloxanes remained stable throughout the study period, whereas those of SMCs shifted from nitro to polycyclic musks. The estimated daily intakes (EDIs) of siloxanes and SMCs arising from ingestion were greater than from dermal absorption of indoor dust. The EDIs of siloxanes and SMCs associated with indoor dust indicated that children are exposed to these pollutants.

Waterborne polyurethane (WPU) is an environmentally friendly product that can replace organic solvents with water. Still, its linear molecular chain structure and the presence of hydrophilic groups greatly affect water resistance and mechanical properties, limiting its wide application in the field of coatings. Herein, a series of fluorosilicone modified waterborne polyurethanes (FSiWPUs) were prepared by introducing tridecafluoro‐nonanol (TFN) and (3‐aminopropyl) triethoxysilane (APTES) into the ends of molecular chains of WPUs. These chains were constituted by different soft segments, including polybutylene adipate glycol, polycarbonate diol, or polytetramethylene ether glycol. Then fluorine element in TFN migrates and aggregates onto the surface during FSiWPU film‐forming to reduce the surface energy. Meanwhile, the hydrolytic condensation of APTES forms a Si–O–Si micro‐crosslinking structure. As a result, the two capping agents enable the modified FSiWPU to have better hydrophobicity, water resistance, and mechanical properties. The research results show that when the TFN:APTES molar ratio of capping agents introduced is 8:2, the static water contact angles of FSiWPUs with different soft sections reach 161.4°–165.3° and the maximum water absorption rate reduce to 8.9%–13.78%. Due to the simultaneous improvement of hydrophobic, water resistance, and mechanical properties, the modified FSiWPUs become the most promising candidates for superhydrophobic coatings. [ABSTRACT FROM AUTHOR]

The spillage of oil causes severe and long-lasting impacts on both the environment and human life. It is crucial to carefully reconsider the methods and techniques currently employed to recover spilled oil in order to prevent any possible secondary pollution and save time. Therefore, the techniques used to recover spilled oil should be readily available, highly responsive, cost-effective, environmentally safe, and, last but not least, they should have a high sorption capacity. The use of sorbents obtained from natural materials is considered a suitable approach for dealing with oil spills because of their exceptional physical characteristics that support sustainable environmental protection strategies. This article presents a novel sorbent material, which is a composite siloxane foam filled with bentonite clay, aimed at enhancing the hydrophobic and oleophilic behavior of the material. The thermal treatment of bentonite optimizes its sorption capacity by eliminating water, and increasing the surface area, and, consequently, its interaction with oils. In particular, the maximum sorption capacity is observed in kerosene and naphtha for the bentonite clay thermally treated at 600 °C, showing an uptake at saturation of 496.8% and 520.1%, respectively. Additionally, the reusability of the composite foam is evaluated by squeezing it after reaching its saturation point to determine its sorption capacity and reusability. [ABSTRACT FROM AUTHOR]

Tributaries are important for fish recruitment and diversity. Here, we examine the biological impact of inorganic and organic contaminants in Paint Branch stream (PBS), a tributary of the Anacostia river in Washington D.C. The Anacostia has suffered severe ecological damage because of decades of pollution and deposited wastewater runoff; however, PBS, which connects to the northern part of the river, is forested and less urbanized, suggesting higher water quality. However, the impact of PBS water on early fish development has not been studied. To address this question, we examined if chronic (28 day) exposure to water collected from PBS can support the proper early development of zebrafish (Danio rerio), a vertebrate model in toxicological studies. We assessed their overall growth and swimming behaviors and correlated these results with a water quality analysis. The water chemistry identified high levels of calcium, sodium, and nitrate in PBS water samples. A gas chromatography–mass spectroscopy analysis of extracted non-polar compounds in the water column revealed siloxanes (congeners D6–D10) were the only component identified with >90% certainty. In our fish experiments, we observed age-dependent increases in growth and eye development, consistent with normal development. In contrast, general swimming behaviors showed an early increase in angular velocity at 7 days postfertilization (dpf; p = 0.001) and a decreased total distance traveled at 14 dpf (p = 0.015) for PBS-treated larvae. Using the open field test, we observed that the PBS-treated fish made fewer visits to the edge at 7 (p = 0.01), 14 (p < 0.001), and 21 dpf (p = 0.038) and spent significantly more time at the edge at 21 dpf (p < 0.001). Fewer visits to the center were also noted at 14 and 21 dpf, suggesting reduced overall movement at these two ages in response to chronic PBS water exposure. Interestingly, by 28 dpf, no differences were noted in any parameter measured. Overall, these results indicate zebrafish larvae grew well in PBS water; however, their reduced movement and anxiogenic behavior suggested subtle behavioral abnormalities. The identified chemicals likely originated from runoff or sewage and have potentially deleterious consequences for fish living in PBS or migrating to/from upstream spawning/nursery locations. [ABSTRACT FROM AUTHOR]

The thermal stability of siloxanes has significant influence on the selection of working fluid and the performance of organic Rankine cycle systems. In this study, a thermal decomposition experimental apparatus was designed to measure the thermal stability of hexamethyldisiloxane (MM), octamethyltrisiloxane (MDM), and their mixtures; a reaction kinetics model based on first order reaction theory was built to analyze the thermal stability of siloxane mixture fluids in a long operation period. And the influence of the mass fraction and evaporation temperature on the net power and thermal efficiency of the system was analyzed under the constraints of thermal stability. The results showed that the thermal stability of MDM was worse than that of MM, and the mixture of MM and MDM had significant inhibition effects on the de-composition of pure fluids. The activation energy of decomposition reaction was 50.50 kJ/mol, and the pre-exponential factor was 5.80 × 10−3 s−1. With the evaporation temperature limit, the net power and thermal efficiency were both lower than those without the evaporation temperature limit. Comparing the obvious decrease in the thermal efficiency, the change of the net power was limited. Siloxane mixtures emerged as a superior choice for ORC systems in the conditions of this paper. MM/MDM (0.6/0.4) improved the net power and heat efficiency of the system by 8.1% and 1.7%, respectively, comparing with that of the pure working fluids. [ABSTRACT FROM AUTHOR]

Upconversion nanoparticles (UCNPs), as near‐infrared (NIR) absorbers, are promising materials for use in flexible NIR photodetectors, which can be applied for wearable healthcare applications due to their advantages in a broad spectral range, high photostability, and biocompatibility. However, to apply UCNPs in wearable and large‐area integrated devices, water stability and micro‐patterning methods are required. In this work, the UCNPs are encapsulated with a siloxane polymer (UCNP@SiOx) via a sol–gel process to enable photo‐patternability and photo‐stabililty in water conditions. The UCNP@SiOx can be photo‐patterned down to micron‐scale feature sizes and exhibit no significant decrease in upconversion photoluminescence (PL) intensities and PL decay time after immersion in water for 2 h. Moreover, UCNP@SiOx is evaluated by an in vitro biocompatibility test and found to be non‐toxic. By integrating the UCNP@SiOx with MoS2 phototransistors (MoS2 + UCNP@SiOx), the devices exhibit enhanced responsivity (0.79 A W−1) and specific detectivity (2.22 × 107 Jones), which are 2.8 times higher than in the bare MoS2 phototransistors, and excellent mechanical durability over 1000 cycles of 20% compression and re‐stretch test. This work opens the way for the facile synthesis of water‐stable and photo‐patternable siloxane‐encapsulated UCNPs and a strategy for fabricating high‐performance flexible NIR phototransistors through wavelength conversion. [ABSTRACT FROM AUTHOR]

A block spatially cross-linked silicon-oxide copolymer and silicon oxide modified with methyl groups were synthesized catalytically at room temperature using oligomeric methylmethoxysiloxane and zirconium oxychloride (ZOC) octahydrate. The mechanism of curing of siloxane is considered. The thermal stability of compositions containing 5, 10, and 15 wt % of ZOC, which is 450–500°C, was found. Composites reinforced with various fabrics were obtained, and their bending strength was measured. The composition of gaseous products released from the cured composites at 50–700°C was found. The moisture and water resistance of the reinforced composites were tested, and it was shown that there is no change in mass of the samples during soaking in water. The survivability of compositions is considered. Measurements of the oxygen index of the cured polymer showed that spontaneous combustion is not maintained in pure oxygen. There is no improvement in the deformation of binders based on the hybrid polymer. [ABSTRACT FROM AUTHOR]

Background: Superhydrophobic materials which have contact angle higher than 150°, considering their widespread applications, are very important for researchers. Method: In this research, silica nanopowder was synthesized successfully using inexpensive sodium silicate source and very simple and facile method. Synthesis of hydrophobic solution was carried out by sol-gel method. The surface modification of silica nanopowder was performed using different silane/siloxane polymers and was deposited on glass slides. For characterization of the samples XRD, FESEM, EDX, TEM, FTIR, and Raman analysis were used. Results: The XRD result shows a very wide peak at 2q = 24.7° which indicates the amorphous nature of the silica particles. The results of the performed characteristics confirm the synthesis of silica nanopowder with the size of less than 25 nm. The EDX spectrum shows that only Si and O elements are present in the structure and no impurities are visible. The contact angle between water droplet and thin films was measured and the effect of different synthesis parameters on the contact angle was studied. Among the studied polymers and solvents, the most hydrophobicity was obtained using TMCS polymer and xylene solvent. The optimized sample has a maximum contact angle of 150.8°. Conclusion: The synthesized thin films have superhydrophobic properties and the method used in this research can be developed for use in industrial applications.

The purpose of this study is to investigate the direct effect of using a blowing agent of siloxane (1, 1, 3, 3-tetramethydisiloxane) on the thermo-physical properties of the foamed epoxy. These properties are: density, glass-transition temperature, thermal conductivity and thermal expansion. The work has been conducted experimentally by manufacturing several specimens with different siloxane contents as: 0, 5, 10, 15 and 20 wt%. The properties of the specimens have tested under suitable conditions using different reliable instruments: differential scanning calorimetry, Lee-discs apparatus, and push rod dilatometer. Scanning electron microscope was used as well to analysis the morphological characteristics of the epoxy with respect to the pores generated by the blowing agent. In general, the foamed epoxy has shown different sizes of pores and extra crosslinking which leads to increase the glass-transition temperature of the material. Results show that the addition of 20% siloxane to the neat epoxy (as maximum) leads to: decreasing by 50% in bulk density, increasing by 20% in glass-transition temperature, decreasing by 30% in thermal conductivity, and decreasing by 75% in thermal expansion.

The realization of aerospace vehicle technologies demanding extreme service conditions is facilitated by the development of materials with greater oxidative stability at high temperatures. Thermal performance of polymer composites can be increased by incorporating a hybrid (organic-inorganic) resin as a thermal barrier coating. One such resin system, meta -poly (carborane-siloxane-arylacetylene) (m -PCSAA), developed by the U.S. Naval Research Laboratory, shows potential for such application and is further investigated in this work. The resin has a low viscosity (0.1 Pa s) with large processing window (2.5 h) from 100°C to 230°C. These processing characteristics are advantageous for infusion processes or the inclusion of fillers for coating applications. Curing was accomplished in two stages, corresponding to two exothermic reactions. After the first curing stage, the resin exhibits elastomeric behavior, and after the second curing stage is rigid with a high glass transition temperature (∼330°C). The materials exhibited high char yields (89%) in air at 1000°C and may be useful in space or for attritable technology. No cracks were observed during long-term service at 288°C, but significant degradation and cracking were observed after aging at 316°C. The materials exhibited high coefficients of thermal expansion; 186.9 and 168.6 μm/(m∙°C) after first and second curing stage respectively. Similar to epoxies and polyimides, the resin acquired up to 3% moisture at 70°C and 85% relative humidity. [ABSTRACT FROM AUTHOR]

Eco‐friendly mixtures may substitute pure working fluids in thermodynamic cycle processes, yet the existing calculation approaches of mixture condensation are complex due to iterative procedures and multiple input data. To simplify condenser design, this project aims for a new calculation method of mixtures. On this behalf, experimental data for the condensation of ethanol/water and ethanol/octamethyltrisiloxane is provided within a wide composition range to identify the most influential parameters. Finally, a practical prediction method for heat transfer coefficients of mixtures is suggested. [ABSTRACT FROM AUTHOR]

According to the published literature and information, the capacity and output of silicone methyl monomer, the import and export of primary polysiloxane, the revenues of listed silicone enterprises, the new projects, the formulation of policies and standards in silicone in 2022 were summarized, and the R&D in silicone industry (including R&D investment, self-developed projects and R&D priorities) was also introduced. [ABSTRACT FROM AUTHOR]