Potassium Methyl Research Articles

A Potassium Methyl Silicate/MnO2 Composite for the Rapid Removal of Dyes from Water

AbstractDye wastewater causes significant harm to the environment and human health. Adsorption is one of the most effective technologies for treating dye wastewater owing to its straightforward operation, strong applicability, and low cost. However, traditional adsorbents have drawbacks, including complicated preparation processes, low adsorption capacity, and challenges with separation, recovery, and regeneration, which fail to meet practical application requirements. Therefore, the development of adsorbents with high adsorption capacity, easy separation, and reusability is urgently required for the treatment of dye‐contaminated wastewater. Potassium methyl silicate (PMS)@MnO2 complex particles (PMS@MnO2) were successfully synthesized by adding a PMS solution to a potassium permanganate (KMnO4) solution at a molar ratio of PMS to MnO2 of 1:1. The PMS@MnO2 complex is rich in functional groups and exhibits good hydrophobicity. The PMS@MnO2 complex particles demonstrated excellent adsorptive capacity (989.1 mg/g) for methylene blue (MB) with rapid degradation, achieving over 75% of their adsorptive capacity within 5 min. The adsorption process was found to be pH‐responsive and exothermic. Under neutral and alkaline conditions, the negative charges in the oxygen‐containing groups on PMS@MnO2 combine with the positive charges in the nitrogen atoms of MB via electrostatic forces. However, under acidic conditions, MB was adsorbed via hydrogen bonding and n‐π interaction between MB and PMS@MnO2. The spent adsorbent was reused for at least five cycles.

Effect of silicon impregnant on freeze–thaw durability of silane-treated recycled aggregate concrete

To enhance the freeze–thaw durability of saline-treated recycled aggregate concrete, the impact of three types of silicon impregnants (organosilicon, methyl sodium silicate, potassium methyl silicate) applied on the recycled aggregate concrete surface and the interior was studied. By conducting salt freeze–thaw test and observing recycled aggregate concrete surface microstructure after freeze–thaw cycles, the performance of impregnants in enhancing the salt freeze–thaw durability of silane-treated recycled aggregate concrete can be ranked as follows: organosilicon (internal) ≈ methyl sodium silicate (internal) > organosilicon (external) > potassium methyl silicate (external). Microstructure images confirm impregnants’ ability to reduce surface cracks, correlating with freeze–thaw resistance. The optimal strategy involves a 50 % combination of organosilicon internally and silane externally, with economic and practical implications for construction in cold areas.

Multifunctional Trifluoroborate Additive for Simultaneous Carrier Dynamics Governance and Defects Passivation to Boost Efficiency and Stability of Inverted Perovskite Solar Cells

AbstractThe main obstacles to promoting the commercialization of perovskite solar cells (PSCs) include their record power conversion efficiency (PCE), which still remains below the Shockley–Queisser limit, and poor long‐term stability, attributable to crystallographic defects in perovskite films and open‐circuit voltage (Voc) loss in devices. In this study, potassium (4‐tert‐butoxycarbonylpiperazin‐1‐yl) methyl trifluoroborate (PTFBK) was employed as a multifunctional additive to target and modulate bulk perovskite defects and carrier dynamics of PSCs. Apart from simultaneously passivating anionic and cationic defects, PTFBK could also optimize the energy‐level alignment of devices and weaken the interaction between carriers and longitudinal optical phonons, resulting in a carrier lifetime of greater than 3 μs. Furthermore, it inhibited non‐radiative recombination and improved the crystallization capacity in the target perovskite film. Hence, the target rigid and flexible p‐i‐n PSCs yielded champion PCEs of 24.99 % and 23.48 %, respectively. More importantly, due to hydrogen bonding between formamidinium and fluorine, the target devices exhibited remarkable thermal, humidity, and operational tracking at maximum power point stabilities. The reduced Young's modulus and residual stress in the perovskite layer also provided excellent bending stability for flexible target devices.

Multifunctional Trifluoroborate Additive for Simultaneous Carrier Dynamics Governance and Defects Passivation to Boost Efficiency and Stability of Inverted Perovskite Solar Cells.

The main obstacles to promoting the commercialization of perovskite solar cells (PSCs) include their record power conversion efficiency (PCE), which still remains below the Shockley-Queisser limit, and poor long-term stability, attributable to crystallographic defects in perovskite films and open-circuit voltage (Voc) loss in devices. In this study, potassium (4-tert-butoxycarbonylpiperazin-1-yl) methyl trifluoroborate (PTFBK) was employed as a multifunctional additive to target and modulate bulk perovskite defects and carrier dynamics of PSCs. Apart from simultaneously passivating anionic and cationic defects, PTFBK could also optimize the energy-level alignment of devices and weaken the interaction between carriers and longitudinal optical phonons, resulting in a carrier lifetime of greater than 3 μs. Furthermore, it inhibited non-radiative recombination and improved the crystallization capacity in the target perovskite film. Hence, the target rigid and flexible p-i-n PSCs yielded champion PCEs of 24.99 % and 23.48 %, respectively. More importantly, due to hydrogen bonding between formamidinium and fluorine, the target devices exhibited remarkable thermal, humidity, and operational tracking at maximum power point stabilities. The reduced Young's modulus and residual stress in the perovskite layer also provided excellent bending stability for flexible target devices.

Study on improvement of waterproofing performance of CCCW with silicone waterproof material and waterbased capillary inorganic waterproofer

The silicone waterproof material and waterbased capillary inorganic waterproofer possess the advantages of rapid film formation and significant hydrophobic effect. In this study, the material composition and mixing ratio of the silicone waterproofing material and waterbased capillary inorganic waterproofing were investigated by multiple performance tests. The results indicated that a white coating was formed on the surface when the mixing ratio of isobutyl-triethoxy-silane and isooctyl-triethoxy-silane was more than 69 %. When the content of sodium and potassium methyl silicate exceeded 0.5 %, respectively, there was an upward trend of contact angle while the reduction in water absorption gradually decreased. Meanwhile, the contact angle and water absorption height of silicone waterproof material were tested. The results showed that the coating performance and hydrophobicity were the best when the mixing ratio of isobutyl-triethoxy-silane, isooctyl-triethoxy-silane, sodium methyl silicate, and potassium methyl silicate was 1.5:0.2:1:0.5. When the matrix mortar specimen was made of Cementitious Capillary Crystalline Waterproofing Materials (CCCW), the lowest water absorption height and water absorption of the experimental group consisted of sodium silicate, sodium tetraborate, sodium phosphate, and sodium hydroxyethyl cellulose were 316.7 % and 39%, respectively. The lowest water absorption height and water absorption of the experimental group consisted of sodium silicate, sodium tetraborate, nano-silica, and sodium hydroxyethyl cellulose were 215.4 % and 28 %, respectively. The results showed that CCCW combined with the experimental group consisted of sodium silicate, sodium tetraborate, sodium phosphate, and sodium hydroxyethyl cellulose had better waterproofing effect.

Preparation, Characterization, and Mechanistic Considerations for 1,1,1-Tri(thioacetyl)ethane and 1,1-Di(thioacetyl)ethene.

Two new compounds, 1,1,1-tri(thioacetyl)ethane and 1,1-di(thioacetyl)ethene, arose during reactions of acetyl methoxy(thiocarbonyl) sulfide with potassium methyl xanthate. Relevant mechanisms were elucidated, which in turn suggested novel streamlined routes to these same compounds. Several further transformations of the title compounds were demonstrated, suggesting their potential synthetic utility.

Four Routes to 3-(3-Methoxy-1,3-dioxopropyl)pyrrole, a Core Motif of Rings C and E in Photosynthetic Tetrapyrroles.

The photosynthetic tetrapyrroles share a common structural feature comprised of a β-ketoester motif embedded in an exocyclic ring (ring E). As part of a total synthesis program aimed at preparing native structures and analogues, 3-(3-methoxy-1,3-dioxopropyl)pyrrole was sought. The pyrrole is a precursor to analogues of ring C and the external framework of ring E. Four routes were developed. Routes 1-3 entail a Pd-mediated coupling process of a 3-iodopyrrole with potassium methyl malonate, whereas route 4 relies on electrophilic substitution of TIPS-pyrrole with methyl malonyl chloride. Together, the four routes afford considerable latitude. A long-term objective is to gain the capacity to create chlorophylls and bacteriochlorophylls and analogues thereof by facile de novo means for diverse studies across the photosynthetic sciences.

Novel prepared nano potassium methyl siliconate as antioxidant for nitrile rubber

In this work, novel potassium methyl siliconate (PMS) was employed as a new nano-type antioxidant for acrylonitrile-butadiene rubber (NBR). NBR/PMS composites were produced by incorporating various contents of the prepared compound as anti-ageing agents (PMS) to improve the heat resistance of these composites. Potassium methyl siliconate (PMS) was prepared, and its chemical structure was confirmed by different elemental analyses. The curing properties, filler dispersion, thermo-oxidative ageing test, mechanical properties, FTIR, and TGA of the NBR/PMS composites were evaluated. It was detected by TEM images of PMS. The particles had a rhombic shape, and the particle size ranged from 1.23 nm to 7.84 nm. PMS could successfully promote the interfacial interaction between rubber and filler and the uniform dispersion of silica particles into the NBR matrix. As a result, the mechanical characteristics of the NBR/PMS composites were significantly improved, and they were superior to those of the NBR/TMQ composites with similar filler contents. Furthermore, the crosslinking density of the NBR composites was reduced after adding PMS (an antioxidant), which had a great effect on the mechanical properties. The results exhibited that PMS dramatically enhanced the solvent extraction resistance and the thermo-oxidative ageing resistance of NBR/silica composites more efficiently than TMQ. Overall, this work extended the application scope of PMS to develop novel and effective antioxidants for elastomers.

In Situ Shale Wettability Regulation Using Sophisticated Nanoemulsion to Maintain Wellbore Stability in Deep Well Drilling.

Wettability alteration of the shale surface is a potential strategy to address wellbore instability issues arising from shale hydration. In this study, we have explored an oil-in-water (o/w) nanoemulsion, in which soluble silicate (lithium silicate and potassium methyl silicate) as the aqueous phase and organosilanes (3-methacryloxypropyltrimethoxysilane (KH570) and n-octyltriethoxysilane (n-OTES)) as the oil phase, as a shale inhibitor via forming a hydrophobic "artificial borehole shield" in situ on shale surfaces to maintain wellbore stability in high-temperature drilling operations. The shale dispersion test showed the highest shale recovery of nanoemulsion was up to 106.4% compared to that of water (20%), and recovered shale cuttings remained at the original integrity after hot rolling at 180 °C, indicating superior inhibition performance and resistance to elevated temperatures. Moreover, recovered shale cuttings manifested water repellency upon reimmersion in water, ascribed to the hydrophobic film, preventing water from permeating into the shale. The results of the contact angle measurement elucidated that the film wettability, from hydrophilic to superhydrophobic (ranging from 9.6-154°), can be achieved by altering the n-OTES-to-KH570 weight ratio from 0.2 to 2.25, and the film with the highest hydrophobicity (154°) and the lowest surface energy (3.17 mJ·m-2) can be obtained at a ratio of 1.3. Scanning electron microscopy images demonstrated that the superhydrophobic film was composed of tightly stacked reticulate nanofilaments with a diameter of 7-17 nm and several micrometers in length and overlapped well-distributed nanospheres with a diameter of 30 nm. X-ray diffraction and Fourier transform infrared spectroscopy confirmed the film was crystalline silica grafted with long-chain alkylsiloxane. It is assumed that the unique micronanostructure combined with the siloxane modification contributed to the hydrophobicity. Consequently, this study provides a potential alternative solution for wellbore stabilization in deep well drilling engineering by employing nanoemulsion as a shale hydration inhibitor via forming a protective film with controllable wettability. Furthermore, it can be conferred a practical application due to easily available, less hazardous, and cost-effective materials.

Effects of Nanomaterials on Engineering Performance of a Potassium Methyl Siliconate–Based Sealer for Cementitious Composite

Effects of Nanomaterials on Engineering Performance of a Potassium Methyl Siliconate–Based Sealer for Cementitious Composite

Potassium methyl silicate (CH5SiO3Na) assisted activation and modification of alkali-activated-slag-based drying powder coating for protecting cement concrete

Alkali-activated materials (AAMs) have attracted extension attention as a promising material for protective coating, while its protective efficiency was limited due to inherent poor anti-permeability when subjected to aggressive marine environments. In this work, a novel strategy for hydrophobic modification of alkali-activated slag (AAS) by compositing potassium methyl silicate (PMS) to produce a protective coating for reinforced concrete was reported. Results show that PMS had an assisted-alkali activation, and could graft hydrophobic groups (–CH3) on the C-A-S-H/C-S-H gel chemical structure by condensation reaction. While PMS had a retard effect and reduced mechanical property due to the decreased binding energy of atoms and condensation degree of gel. The coating with 5 wt% PMS obtained a compacted microstructure, where gel production increased 26 %, porosity decreased 54 %, and harmless pore volume improved 14 %. The fabricated coating had excellent protective properties, which showed a bonding strength of 1.60 MPa, water contact angle of 128°, water absorption of 2.8 %, chloride ion penetration coefficient of 5.453 × 10-12 m−2/s, and the corrosion rate of reinforced rebar decreased by 97 %.

Methyl silicate promotes the oxidative degradation of bisphenol A by permanganate: Efficiency enhancement mechanism and solid-liquid separation characteristics

Permanganate (Mn (VII)) is an environmentally-friendly mild oxidant in the field of advanced oxidation treatment, however, manganese colloids are produced as byproducts, which is difficult to separate from water, resulting in secondary pollution. This study used potassium methyl silicates (PMS) as surface modifiers to improve the aggregation of colloidal particles by increasing the hydrophobicity of the colloidal surface, and then explored the oxidation of bisphenol A (BPA) by Mn (VII) under the influence of potassium methyl silicate and the solid-liquid separation performance of the reaction system. The results showed that PMS and sodium silicate (SS) substantially enhanced the degradation of BPA by Mn (VII), and the promotion effect of potassium methyl silicate was greater than that of sodium silicate. PMS provided not only enough adsorption sites for MnO2 colloidal particles formed in the reaction process, but also reaction space for Mn (VII) to catalyze the oxidation of BPA. PMS combined with the hydroxyl group of MnO2 through hydrogen bonds and forms hydrophobic PMS-MnO2 complexes which accelerated sedimentation by polycondensation. The strong adsorption ability of in situ formed MnO2 colloids also accelerated the deposition of PMS-MnO2 complex. This study solved the low efficiency problem of Mn (VII) oxidation degradation of organic pollutants and difficult separation of manganese containing colloids and provided a new strategy for the efficient utilization of Mn (VII).

Stability of cellulose phosphates in alkalic solutions

The stability of cellulose phosphates(III) and cellulose phosphates(V) in suspensions in 2 M potassium hydroxide solutions in the temperature range of 25–80 °C were investigated. The release of phosphorus compounds in eluates was determined by 31P NMR using methyl phosphonic acid (potassium methyl phosphonate) as internal standard.

Application of Hybrid Silicate as a Film-Forming Agent in High-Temperature Water-Based Drilling Fluids.

Effective control of shale swelling and lost circulation using drilling fluid is considered the dominant strategy for maintaining borehole stability, especially drilling operations in deep oil and gas wells. In this work, a hybrid silicate that contains lithium silicate and potassium methyl silicate (PMS) was employed as a film-forming additive to reduce shale hydration and filtration loss in the high-temperature drilling fluid. Scanning electron microscopy (SEM) results revealed that a dense quartz crystal film coating on the shale can be formed in a hybrid silicate solution when the temperature exceeds 150 °C. The in situ-formed film on the shale surface with a thickness of 60–130 μm was composed of fibrous crystalline silica. Furthermore, the aqueous hybrid silicate exhibited enhanced hydration inhibition ability by preventing water invasion of the formation. Aqueous hybrid silicate with a concentration of 0.5–3 wt % lithium silicate and 0.1–0.2 mol/L PMS was first chosen to obtain the optimum concentration according to the hydration inhibition ability and film formation characteristics. The hybrid silicate was added into a drilling fluid formulation applicable in high-pressure and high-temperature conditions, and the rheological characteristics and filtration properties were investigated. The results confirmed that drilling fluids with the addition of hybrid silicate can mitigate variation of viscosity and yield point before and after aging at 180 and 220 °C. Besides, the filtration behavior was also improved by adding hybrid silicate into the drilling fluid. A lower filtration loss was observed at the concentration of 1.0 wt % lithium silicate and 0.2 mol/L potassium methyl silicate, which showed 63 and 50% HPHT fluid loss reduction for unweighted and weighted formulations at 205 °C and 3.5 MPa, respectively. In addition, the drilling fluid featured stable rheological and filtration properties and excellent shale hydration inhibition characteristics when exposed to high temperatures, making it a promising candidate for drilling in deep oil and gas wells.

The use of modified wood in the construction of wastewater treatment plants in coal mines of Kuzbass

PurposeThe purpose of the study is to show an improvement in resistance (permeability) and durability (residual strength) of modified wood compared to natural wood.Design/methodology/approachA relevance way to increase the durability and resistance of wood is processing with polymers. Novosibirsk State Technical University, Novosibirsk State University of Architecture and Civil Engineering (Sibstrin) and the Norilsk State Industrial Institute researched the resistance of elements of mine treatment plants made of wood modified with synthetic polymers. The study was carried out according to V.A. Kucherenko. Modification of such species as birch and pine can significantly increase wood resources by extending its service life and improving its physical and mechanical properties. Latex-organosilicon modifier was used as a modifier.FindingsLatex clogs the capillaries of wood, preventing the penetration of aggressive solutions into it, and potassium methyl silicate interacts with hydrophilic OH groups, increasing the water-repellent properties of the surface of cells and wood capillaries.Originality/valueThe results of long-term and predictive tests of modified wood in aggressive environments of treatment facilities are presented. As a result, diffusion of aggressive media into the wood becomes more difficult and its resistance and durability increase.

Study of the Adhesion of Silicate-Based Coating Formulations on a Wood Substrate

Silicate coatings are environmentally friendly inorganic-based products that have long been used for mineral substrates and protection of steel against corrosion. The development and acceptance of these coatings in the wood sector require some adjustments in formulations or special preparation of the surface to be coated to obtain durable finishes. In this work, the adhesion of various silicate-based formulations to a beech wood substrate (Fagus sylvatica L.), was assessed with the main objective to study relevant parameters and potential improvements. Adhesion strength was determined by pull-off and cross-cut tests. Other coating properties such as scratch, impact, and water resistance were also determined. Surface roughness and interface were analyzed using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), and coating curing was studied by attenuated total reflection-infrared spectroscopy (ATR FTIR). The results showed that adhesion was highly dependent on formulation, penetration of the coatings into wood, and mechanical anchoring. Increasing the content of solid particles in the coating formulations or adding a polyol (glycerol, xylose), which probably acted as a coalescent, considerably decreased the adhesion strength, probably by blocking penetration into the wood by forming aggregates. Adhesion was improved by pre-mineralization of the surface, and substitution of a part of the potassium silicate binder with potassium methyl siliconate reduced the formation of cracks caused by dimensional instability of the wood.

Synthesis of potassium methyl ester as foaming agent

Forest and land fires in Indonesia have been historically causing extensive damages and losses on economies, ecosystems, and environment, and affects all life in the region. Forest fire management in Indonesia still relies on water that is less effective than foaming agents i.e., extinguishers. Chemicals used in conventional extinguishers are expensive. Foaming agents based on palm oil can be used as an alternative for the extinguishers. The foaming agent synthesized in this study was potassium methyl ester, made from palm oil methyl ester (ME), with saponification by adding potassium hydroxide (KOH). The forming performance tests (foam stability and forming ability) and form related physicochemical analyses (surface economies, interface surface tension, density, and contact angle) of potassium methyl ester were conducted with ME:KOH molar ratio of 1:1; 1:1.25; and 1:1.5 and the saponification duration of 1.5, 2 and 2.5 hours. The molar ratio had significant effects on foam stability, interface surface tension, density, and contact angle. The duration of the saponification had a significant effect on density. There was no significant effect of the interaction between the molar ratio and saponification duration. The best foaming agent selected by the ranking method (composite performance index) of foam stability, foaming ability, and surface tension were one with ME:KOH molar ratio of 1:1 and 1.5 hours saponification.

Development of a transparent silica-titania-methyl siliconate nanocoating with photocatalytic-hydrophobic properties aided by response surface method

This work aims to optimize the factors affecting silica-titania-methyl siliconate photocatalyst hydrophobic coatings prepared through a straightforward chemical method using tetraethyl-orthosilicate (TEOS: C8H20O4Si), tetraethyl-orthotitanate (TEOT: C8H20O4Ti) and potassium methyl siliconate (PMS: CH3SiO3K3). Field Emission- Scanning electron microscopy (FE-SEM) images showed that a uniform and crack-free coating with a thickness of nearly 90 nm was formed on the surface at the low temperature. FT-IR spectroscopy confirmed the formation of silica and titania particles on the coating. Response Surface Method (RSM) with 29 experiments was implemented, and the contact angle with photocatalytic efficiency was considered as the response to be optimized. Four effective factors of the mole ratio of TEOT/TEOS, PMS/TEOS, H2O/TEOS, and pH were determined in three levels, which were equal to 35, 0.06, 5.5, and 2, respectively, obtained by an Analysis of Variance (ANOVA) over the experiment results. In the mentioned conditions, the expected result for the contact angle and photocatalytic efficiency were 139˚ and 43.5%, respectively, and the confirmation test reached 141° and 41%. Consequently, TEOT/TEOS and PMS/TEOS molar ratios were found to be the most effective factors in both photocatalytic and hydrophobicity of the coating.

Formulation and performance test of palm-based foaming agent concentrate for fire extinguisher application

The utilization of foaming agent for fire extinguisher application improves the efficiency of water as a fire extinguishing agent, lowers surface tension, and acts as a foaming agent. The formed foam cools the fire down and covers the burned material to avoid it from further contact with oxygen which may reignite the fire. This study aimed to produce and assess the performance of foaming agent concentrate from palm oil as a fire extinguisher agent. In the performance test, measurements were taken on foam stability, foaming ability, surface tension, interfacial tension, viscosity, contact angle, density, and specific gravity. The formulation was conducted by using the best produced potassium palmitate, potassium methyl ester, and sodium lauric combined with diluents, chelating agent, and other additives at various composition comparisons. The produced foaming agent concentrate was found to be in a rather paste and liquid form with viscosity of 2.34 – 253 cP. It was also found that the resulted foaming agent concentrate dissolved in water at the concentration rate of 1% had a foam stability level of 30-91%, foaming ability of 288 – 503%, surface tension of 19.68 – 25.05 dyne/cm, interfacial tension of 0.54 – 4,20 dyne/cm, viscosity of 1.00 – 1.05 cP, contact angles of 53.75 – 63.79° at 0 minute and 11.84 – 22.42 ° at minute 10, density of 0.99586 – 0.99612 g/cm3, and a specific gravity of 1.00021 – 1.00046. Based on foam stability, foaming ability, and surface tension parameters, it was concluded that NF5 and NF17 were the best formulas.Compared to the other formulas, NF5 formula had the best droplet diameter (minimum 0.14 mm) and droplet density (maximum 3056 droplets/cm2).

Investigation of the efficiency and potential possibilities of paper protection by siloxan in wet environments

The object of research is unbleached pulp-based winding with a thickness of 70±3 μm. One of the main problems is the use of the research object as a packaging material. Particular attention is required to protect paper when it is used in wet conditions. The presence of a layer of adsorbed water on the surface can adversely affect the physical and technical properties. The degree of such influence is determined by the energy state of the surface of the substrate and by the wettability of its water in the liquid-crystal state and the adsorption of water vapor. To ensure the stability of this paper in aggressive media, its modifications are carried out by immersion in 3–5 %, by volume of the solution in water, organic solvents or an aqueous dispersion of organosilicon products. A study of the hydrophobic properties and the mushroom resistance of the surface of the treated paper is also carried out. The results of the investigation of the tensile strength and dielectric parameters of the treated paper are considered. For comparison, IR spectrometry of porous aluminosilicate glass is carried out. One of the main criteria is the tensile strength of the investigated paper treated with silicone coatings. As a result of the conducted studies, it is found that a less tensile force at the level of 84.6–90.1 % of the initial one is fixed when using coatings based on potassium methyl siliconate and its derivatives in various combinations. Therefore, in comparison with untreated paper, the modified one acquires high performance properties in terms of protection in humid environments.