Search

Silica from rice husks (RH) has been used as a starting ingredient in the sonication synthesis of MCM-41 (RH-MCM-41). The impregnation of Fe3+ into RH-MCM-41 pores to produce RH-MCM-41 containing Fe2O3 and Fe (denoted as Fe2O3-Fe-RH-MCM-41) was carried out by examining the effect of various Fe3+ concentrations on the weight percent of Fe-frameworks (Fe3+ that replaces Si4+ in silicate frameworks) and Fe-non-frameworks, i.e., the iron oxide formed outside the silicate frameworks. Fe2O3-Fe-RH-MCM-41 was washed with a 0.01 M HCl solution to remove Fe-non-frameworks from the materials and give Fe-RH-MCM-41 containing Fe-frameworks. The Fe content in Fe2O3-Fe-RH-MCM-41 (Fe-total) and Fe-RH-MCM-41 (Fe-frameworks) for each sample was determined by an AAS (atomic absorption spectrometer), whereas the content of Fe-non-frameworks was calculated from the difference between Fe-total and Fe-frameworks. The XRD (X-ray diffraction) pattern, N2 adsorption-desorption isotherm profile, as well as the TEM (transmission electron microscope) image clearly demonstrate that the RH-MCM-41 exhibits an ordered p6mm hexagonal mesostructure with a large specific surface area and uniform pore size. Based on the weight percents of Fe-frameworks found in each sample, it is clear that the content of Fe-non-frameworks is significantly enhanced compared to that of Fe-frameworks when the more concentrated Fe3+ is used.

A silane-siloxane based water-repellent substance (S-WR) was used as an impregnation material for Scots pine (Pinus sylvestris L.), black pine (Pinus nigra Arnold), sessile oak (Quercus petraea Liebl.), and cedar (Cedrus libani A. Rich). In the impregnation process, the immersion method was carried out for various periods (30 min, 3 h, and 24 h). Following impregnation, physical properties of the wood (retention, contraction, expansion, water intake rate, specific gravity, etc.) were determined. The retention was highest in sessile oak wood (0.96%) and lowest in black pine wood (0.24%). The highest specific gravity value was found in stemless oak (0.86 g/cm³) impregnated for 24 h, and the lowest air-dry specific gravity value was found in Scots pine (0.40 g/cm³) impregnated for 30 minutes Absolutely dry (0% humidity) specific gravity was highest in sessile oak for 24 h (0.83 g/cm³). Shrinkage was highest in the sessile oak control sample (13.5%). The expansion amount was highest in the cedar wood control sample (17.5%) and lowest in sessile oak wood (1.66%). The highest water uptake rate (SAO) was determined in Scots pine wood at 96 h (105%), and the lowest in sessile oak wood in 24 h (8.80%). In summary, silane-siloxane based water-repellent impregnation material was found to be effective in providing dimensional stability in wood.

In order to inhibit the formation of advanced glycation end products (AGEs) and heterocyclic aromatic amines (HAAs) in roasted peanuts, six phenolic acids (caffeic acid, ferulic acid, 4-coumaric acid, vanillic acid, gallic acid and chlorogenic acid) were employed to impregnate raw peanuts before roasting, and the effects of the type and concentration of impregnation solutions on AGEs and HAAs formation during peanut roasting were studied in this work. The results showed that gallic acid and chlorogenic acid could significantly inhibit the formation of Nε-(carboxymethyl) lysine (CML) and Nε-(carboxyethyl) lysine (CEL) with an inhibition rate in the range of 14.7%–24.4% and 13.0%–22.7%, respectively. However, the other four phenolic acids had no inhibitory effect (P > 0.05). What’s more, the inhibitory effects of gallic acid and chlorogenic acid were concentration dependent. Three HAAs including 2-amino-1,6-dimethylimidazo[4,5-b]pyridine (DMIP), 1-methyl-9H-pyrido[3,4-b]indole (Harman) and 9H-pyrido[3,4-b]indole (Norharman) were detected in roasted peanuts. All six phenolic acids could inhibit the formation of DMIP significantly (P 0.05). Ferulic acid and chlorogenic acid had a strong inhibition effect on the formation of 3 HAAs, but there was no obvious concentration dependence.

Microencapsulated phase change materials (MPCMs) incorporated into oak wood via vacuum impregnation have shown promise as thermal energy storage (TES) materials. Physical and chemical properties of MPCMs and resulting Phase Change Energy Storage Wood (PCESW) were analyzed. Scanning electron microscopy and particle size analyses revealed similar particle sizes, while X-ray diffraction (XRD) and Fourier transform infrared spectra confirmed crystal phase and chemical structure. Thermal gravimetric analysis (TGA) and differential scanning calorimetry determined thermal properties, including phase change temperature, enthalpy, thermal stability, and conductivity. The MPCMs exhibited a phase change enthalpy of 146.0 J/g and temperature of 35.0 °C, with excellent thermal stability. The FTIR, XRD, and TGA analyses showed unchanged chemical structure, crystallinity ratios, and decomposition in two stages, respectively. The PCESW exhibited a latent heat storage of 3.02 J/g at 25.4 °C. Decay tests demonstrated noticeably reduced weight loss (1.22% and 1.55%) for MPCMW samples treated with Trametes versicolor and Coniophora puteana, compared to unleached control samples (19.7% and 20.8%). These findings indicate the high efficiency and potential of PCESW as a thermal energy storage material.

Concerns about pollution and global warming have grown in recent years. Efficient coal use is critical for reducing the environmental toll of fossil fuel consumption. This study aims to examine how transition metal chlorides affect the burn-off rate and thermal conversion efficiency of bituminous coal with a high ash content. The analytical methods used include proximate, thermo-gravimetric, morphological, and pyrolysis analyses. This research examined the effect of change in the carbonization temperature, carbonization time, and catalyst concentration on the thermal degradation of high-ash bituminous coal impregnated with ZnCl2. At various ratios, zinc chloride solution was adsorbed onto the coal surface. The treated coal was then heated at different temperatures ranging from 510 to 710°C, under atmospheric pressure, in a furnace without air. This process was carried out to enhance the rate of burnout or pyrolysis. The response surface approach reveals that the carbonization time is a crucial input parameter, followed by the carbonization temperature and catalyst concentration. The response surface methodology analysis yielded a coefficient of determination of 0.9734.

Excessive use of chemical fertilizers causes serious environmental hazards, as only a fraction is really adsorbed by the soil. As part of the solution, the feasibility of using unmodified (UNZC) and surfactant-modified natural zeolite-based composite (SMNZC) fertilizers as support materials for the provision of nutrients to soil on a slow release basis was assessed using column and pot experiments. The characterization of the zeolite materials was done using powder XRD, XRF, SEM, BET, and TGA instruments. The percentage of cationic nutrients released from soil columns containing UNZC increased over time. Their release from SMNZC initially slowed down and became stable as the number of days increased. The percentage of N–NO3− and available P released from UNZC has constantly decreased with time. Their release from SMNZC increased as the number of days increased. The maximum P uptake by maize was observed for the soil treated with SMNZC, and there was no significant difference at all rates. The maximum uptake of Ca (3663.40 ppm), Mg (2617.34 ppm), and Fe (222.83 ppm) was observed at 250 kg/ha of UNZC. The highest uptake of K, Zn, and Cu was also observed for the soil amended with UNZC, irrespective of its application rate. Application of UNZC and SMNZC at the same rate equally affected total nitrogen uptake. Thus, this finding showed that UZNC is a better carrier of cationic nutrients, while SMNZC is preferable for the slow release of NO3− and available P. In conclusion, both the modified and unmodified support forms showed better performance than conventional fertilizer in delivering nutrients slowly and sustainably.

A novel environmentally friendly resorcinol–formaldehyde-free impregnation solution was successfully developed to enhance the interfacial adhesion of ultra-high molecular weight polyethylene (UHMWPE) fiber cords with rubber. The UHMWPE fiber cords were first treated by dopamine (DA) and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane (KH602), followed by impregnation in a mixture of glycerol triglycidyl ether (GTE), diethylenetriamine (DETA) and vinyl pyridine latex. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the chemical composition of the fiber cords surface. The results showed that the impregnation process successfully modified the surface of the UHMWPE fiber cords and did not deteriorate the fiber strength. The H pull-out results showed that the adhesion strength between the modified UHMWPE fiber cords and the rubber increased by 257 % compared to the untreated cords. In addition, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) was employed to characterize the interface morphology of the fiber cords/rubber composites. The formation of a transition layer and the migration of the curatives contributed to the improvement in the interfacial adhesive properties.

The presence of organic and inorganic contaminants such as pesticides, antibiotics, dyes, and heavy metals poses a risk to a human and the environment and therefore needs to be removed. The combination of natural zeolites and magnetic nanoparticles is employed as an excellent adsorbent for these pollutants removal from water. Magnetic zeolites are synthesized by incorporating magnetic nanoparticles, such as iron oxides or ferrites, into the zeolite framework. Various techniques, including co-precipitation, impregnation, and hydrothermal synthesis, have been employed by researchers to create the necessary magnetic zeolite composites and employed them for removing or reducing recalcitrant pollutants present in water or aqueous solutions. Magnetic zeolites have shown great promise in the removal of contaminants present in water. One of its best sides is its ability to separate and reuse materials easily. This review emphasizes magnetic zeolite as an effective adsorbent for water remediation and demonstrates its potential for water treatment. Magnetic zeolite can be used especially in regions where water treatment technologies are not yet met and can address waterborne disease issues. Due to its magnetic properties, and easier recovery and reuse of the adsorbents, the magnetic zeolite adsorption method is cost-effective and convenient

In this work, the effect of changing the Li2MoO4-SrTiO3 (LMO-ST) compositional proportion (1–100 wt%) on the microstructure, dielectric properties, and relative density of LMO-ST composites fabricated at room temperature was investigated. The results showed that increasing the LMO binder content resulted in a higher relative density (up to 93%), but a lower dielectric constant in the range of 75 to 5. Good agreement between the experimental results and the predicted values of relative permittivity was obtained using the Lichtenecker model, reformulated for a three-phase composite system. Modeling further explained the detrimental effects of porosity on the dielectric properties. To address this issue, impregnation with titanium (IV) isopropoxide (TTIP) was found to reduce overall porosity and improve relative permittivity from 72 to 99 at 1 MHz. The room temperature fabrication offers a wide range of relative permittivity for LMO-ST composites.

Nano-constituent incorporation into composites has been extensively studied in the literature due to its improvement in static and dynamic mechanical properties, as well as its prevention from interlaminar crack initiation and propagation. This work introduces a detailed manufacturing process of nano-engineered composite laminates, from impregnation to consolidation, without damaging the initial morphology of carbon nanotubes transferred on prepreg interfaces. Based on prepreg and vertically aligned carbon nanotubes (VACNTs) synthesized on an aluminium alloy (Al) substrate, the impregnation step allows for the transfer of VACNTs onto the prepreg surface through partial resin-rising capillarity. The Al alloy substrate is then removed from the VACNTs through a separation step, ensuring highly effective and repeatable transfer with more than 80% VACNTs transferred onto the prepreg surface. This paper provides insight into the impregnation and transfer processes and guides the choice of process parameters to ensure minimal VACNTs buckling during the consolidation of the hybrid composites at high pressure in an autoclave. [ABSTRACT FROM AUTHOR]

Commercial biodiesel production is becoming popular due to its sustainability and reduced greenhouse gas emissions in comparison to fossil fuels. Biodiesel production involves the co-generation of crude glycerol that is not directly viable. Valorization of glycerol is essential from techno-economic perspective to achieve goals of circular economy. In this study, the glycerol etherification was carried out using tert-butyl alcohol in presence of dodecatungstophosphoric/silica (DTP/SiO2) catalyst for production of tert-butyl glycerol ethers that can be used as fuel additives. A series of DTP/SiO2 catalysts were prepared with various compositions by impregnating heteropoly acids (HPA, H3PW12O40). The product analysis was performed to monitor mono-, di-, and tri-tert-butyl glycerol ethers. The kinetic studies were conducted based on Langmuir–Hinshelwood model. The rate constants were determined from experimental data by regression analysis. The catalysts were characterized by X-ray diffraction, SEM/EDX, and thermogravimetric analysis. Varying DTP loadings resulted in different catalytic activities. Activation energy (38.23 kJ/mol), activation enthalpy (25.94 kJ/mol), activation entropy (− 163.8 J/mol/K), and Gibbs free energy of activation (88.67 kJ/mol) were attained for DTP/SiO2 (20%) catalyst that exhibited the best selectivity for di-tert-butyl glycerol ethers. [ABSTRACT FROM AUTHOR]

In the present work, three zeolite‐beta based catalysts with post impregnation of aluminum are evaluated for conversion of rice husk to furfural at atmospheric pressure in the presence of sodium chloride as promoter. The synthesized catalysts were characterized by nitrogen adsorption–desorption isotherm, scanning electron microscopy, X‐ray diffraction, and pyridine Fourier transform infrared spectroscopy. The activity of in house synthesized/modified catalysts is studied at preliminary optimized reaction conditions of 375°C and 47 min with variation in feed/catalyst/promoter ratio. Purity and yield of furfural was obtained by gas chromatography analysis with flame ionization detector in a batch reactor. Results shows that zeolite beta with 5 wt % post aluminum impregnation gave highest yield of bio‐oil (60.3 wt%) with 88% selectivity toward furfural in the presence of sodium chloride (5 wt% of feed) and sulfuric acid (10 wt% of feed). [ABSTRACT FROM AUTHOR]

In the present research work, ternary composite g-C3N4-WO3/rGO was prepared by using ultrasonic assisted wet impregnation procedure. The prepared ternary composite was characterized by using FT-IR, powder XRD, SEM, and EDX techniques. FTIR studies confirmed the presence of characteristic bonds of the representative components in the composite by showing their characteristic peaks. The XRD pattern of ternary composite g-C3N4-WO3/rGO showed the presence of peaks responsible for monoclinic phase of pure tungsten oxide (WO3) and the characteristic peaks of graphitic C3N4 and GO. SEM studies of g-C3N4-WO3/rGO revealed the presence of randomly dispersed tungsten oxide particles in between agglomerated 2-D layers of carbon nitride and GO sheets. EDX data confirmed the phase purity in the form of elemental composition of the prepared composite and further provided At wt% of each element in the composite. Photocatalytic activity of the synthesized composite was evaluated by performing photocatalytic degradation test of methylene blue (MB). The rate of degradation was measured by using Shimadzu UV-1800 UV-Vis Spectrophotometer by recording the decreasing concentration of dye in terms of their absorbance values. The results exhibited that g-C3N4-WO3/rGO showed better degradation efficiency in 180 min. [ABSTRACT FROM AUTHOR]

The objective of this work was to improve the thermal stability, flame resistance, and surface properties of black poplar (Populus nigra L.) wood via different impregnation methods. The impregnation methods were employed through two distinct modalities: vacuum impregnation and immersion impregnation. Here, poplar wood was impregnated with calcium oxide solutions (1%, 3% and 5%). Fourier-transform infrared spectroscopic analysis revealed a shift in the typical peaks of cellulose, hemicellulose, and lignin depending on the impregnation method and solution ratio. Thermogravimetric analysis and the limiting oxygen index indicated that the samples impregnated with lime solutions exhibited higher thermal stability than the unimpregnated wood. Both impregnation methods caused a decrease in water absorption and thickness swelling of the sample groups. Using a scanning electron microscope, the effect of the impregnation process on the structure of the wood was examined. In terms of surface properties, it was determined that the surface roughness value increased. On the contrary, it was observed that the contact angle value also increased. A significant difference emerged between the applied methods. In conclusion, the applied lime minerals are suitable substances to increase the flame resistance and thermal stability of black poplar wood. [ABSTRACT FROM AUTHOR]

The aim of current work is to develop the uptake of 4-nitrophenol from the liquid phase in a dynamic system by the shaped activated carbon produced through the microwave-assisted technique. The emphasis of research is to understand the effects of production factors on the performance of adsorbents in the dynamic adsorption. Hence, the phosphoric acid ratio, microwave irradiation power, carbonization temperature, and time were changed to identify the suitable conditions for the fabrication of granular and rod-like beds from the cherry, and date stones. It was found that the stone structure and H3PO4/waste ratio significantly affect the adsorption efficiency. The proper acid/waste ratio was determined to be 1.43, and 1.80 for the activation of cherry and date stones to achieve the maximal efficiency in which the power should be fixed at the levels of 600 and 400 W respectively. The equilibrium efficiency increases with the rise in carbonization temperature and time which should be controlled exactly to reach the maximal adsorption capacity, ~ 45 mg g−1 according to the Langmuir isotherm. Owing to the high specific surface area of shaped adsorbents, 350–450 mg g−1, the fabricated beds indicated the appropriate performance for the uptake of nitrophenol due to development of micropores, < 2 nm, in the framework of activated carbon. [ABSTRACT FROM AUTHOR]

The possibility and technical efficiency of the use of the FA-513 nanomodifier in the formulations of lubricants (Nos. 76 and 4S) are confirmed. The optimal concentrations of FA-513 are found with an impregnation method for lubricants in the production of microplastics. The resulting microplastics exhibit increases in physical and mechanical properties of 12–25%. [ABSTRACT FROM AUTHOR]

Flame-retardant impregnation and densification are two major modification techniques to improve the fire safety of wood. Here, these two techniques were combined to prepare flame-retarded wood, aiming at further fire hazard reduction. The delignated Pinus sylvestris L. was impregnated with boric acid (BA) and graphene oxide (GO) solutions, then densified to prepare densified flame-retarded wood named BGO-DW sample. The results revealed that the BGO-DW sample obtained a limiting oxygen index (LOI) value of 47.4 %. Its backside temperature after 1200 s heating was 49 % lower than that of unmodified wood. Besides, the peak heat release rate (PHRR) and total heat release (THR) values of BGO-DW sample were 72 and 62 % lower than those of unmodified wood due to its shorter pyrolysis interval and lower peak mass loss rate (PMLR), as supported by thermogravimetric (TG) analysis. The flame retardancy of BGO-DW sample could be attributed to the formation of compatible char containing C=C aromatic structure, C–O–C cross-linked structure, and boron trioxide (B2O3) structure. These features of BGO-DW sample offer a new method to improve thermal stability, heat insulation, and flame retardancy for wood and wood-based products. [ABSTRACT FROM AUTHOR]

Information about new cesium-containing quartzoid glasses (QGs) obtained as a result of the heat treatment of high-silica porous glasses (PGs) impregnated with aqueous solutions of CsNO3 is presented. Quartzoid glasses have been studied by SEM, X-ray diffraction, flame photometry, and energy-dispersive X‑ray spectroscopy. It has been established that the total content of cesium in the synthesized QGs increases with an increase in the concentration of the impregnating solution of cesium nitrate and an increase in the impregnation time of PGs for the selected synthesis conditions. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of brutian pine (Pinus brutia Ten.) wood impregnation with nanoclay in different concentrations on the chemical and thermal changes, and their impact on the physical and mechanical properties. The samples were impregnated with nanoclay in concentrations of 1%, 3%, and 5%, for 2, 24, and 48 h. Fourier transform infrared spectroscopic analysis revealed a shift in the typical peaks of cellulose, hemicellulose, and lignin depending on the impregnation time and nanoclay ratio. Thermogravimetric analysis and the limiting oxygen index indicated that the samples impregnated with clay solutions exhibited higher thermal stability than the unimpregnated wood. Impregnation with nanoclay caused a decrease water absorption and thickness swelling of the sample groups. The modulus of elasticity, modulus of rupture, and compression strength strength values of samples were improved via impregnation. In conclusion, the applied nanoclay are suitable substances to increase the durability and thermal stablity of brutian pine wood. [ABSTRACT FROM AUTHOR]

A silane-siloxane based water-repellent substance (S-WR) was used as an impregnation material for Scots pine (Pinus sylvestris L.), black pine (Pinus nigra Arnold), sessile oak (Quercus petraea Liebl.), and cedar (Cedrus libani A. Rich). In the impregnation process, the immersion method was carried out for various periods (30 min, 3 h, and 24 h). Following impregnation, physical properties of the wood (retention, contraction, expansion, water intake rate, specific gravity, etc.) were determined. The retention was highest in sessile oak wood (0.96%) and lowest in black pine wood (0.24%). The highest specific gravity value was found in stemless oak (0.86 g/cm³) impregnated for 24 h, and the lowest air-dry specific gravity value was found in Scots pine (0.40 g/cm³) impregnated for 30 minutes Absolutely dry (0% humidity) specific gravity was highest in sessile oak for 24 h (0.83 g/cm³). Shrinkage was highest in the sessile oak control sample (13.5%). The expansion amount was highest in the cedar wood control sample (17.5%) and lowest in sessile oak wood (1.66%). The highest water uptake rate (SAO) was determined in Scots pine wood at 96 h (105%), and the lowest in sessile oak wood in 24 h (8.80%). In summary, silane-siloxane based water-repellent impregnation material was found to be effective in providing dimensional stability in wood. [ABSTRACT FROM AUTHOR]

The cape gooseberry (Physalis peruviana L.) is an exotic tropical fruit of great national and international importance due to its nutritional and organoleptic properties. The objective of this study was to evaluate different postharvest treatments—coating, vacuum impregnation, and immersion—on the conservation of several quality characteristics of cape gooseberry fruit. Moreover, the different conditions of the selected treatments were studied. Weight loss was assessed with a gravimetric analysis of the fresh and treated fruit. Firmness was determined by the instrumental texture. A sensory analysis was conducted using a multidimensional profile approach. Of the treatments evaluated, the lowest weight loss was recorded with the use of coating and immersion. However, the immersion process resulted in the product with the highest overall quality according to the sensory analysis and presented the most appropriate texture according to the firmness values. Finally, in the evaluation of the immersion, a significant influence of the CaCl2 immersion time (p < 0.05) on the firmness values of the product was found, resulting in longer times leading to less firm products. Considering 10% as a commercial standard limit for weight loss, the fruit treated under immersion and coating processes can be stored for at least 12 days. The immersion process is highlighted because it improved the sensory characteristics with respect to the control (i.e., without treatment). Therefore, it is a promising alternative for the postharvest treatment of cape gooseberries. [ABSTRACT FROM AUTHOR]

Copyright of Energy Chemical Industry is the property of Energy Chemical Industry 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.)

To clarify the Ni species of NiO/SiO2-Al2O3 catalysts that are active for ethylene oligomerization, 18 types of NiO/SiO2-Al2O3 were prepared using three Ni-loading methods (i.e., ion-exchange, impregnation, and homogeneous precipitation), with different Ni-loadings (1–20 wt%), and examined with respect to their structure and catalytic activity for ethylene oligomerization. Characterized by N2 adsorption, powder XRD, FE-SEM, H2-TPR, NH3-TPD, and C2H4-TPD showed that Ni species in the catalysts prepared by ion-exchange were mainly ion-exchanged Ni cations. In contrast, Ni species in the catalysts prepared by impregnation were a mixture of ion-exchanged Ni cations and NiO particles, and those in the catalysts prepared by homogeneous precipitation were all NiSiO3 particles. Catalytic-reaction tests at 300 °C and 0.1 MPa revealed the following: the ion-exchanged Ni cations showed the highest C2H4 conversion rate; the NiSiO3 particles showed a moderate reaction rate; and the NiO particles were not active for ethylene oligomerization. We concluded that the high catalytic activity of the ion-exchanged Ni cations was a result of their high dispersion and medium-strength acidity, which together promoted the adsorption and activation of ethylene on, and the desorption of oligomerization products from, the catalyst. [ABSTRACT FROM AUTHOR]

A comparison is made of CrOx–ZrO2–SiO2 catalysts (9 wt % chromium oxide based on Cr2O3); (Cr + Zr)/Si molar ratio of 0.8) synthesized using different orders of introducing components: (i) the simultaneous precipitation of all components, (ii) the deposition of CrOx on ZrO2–SiO2 via impregnation, and (iii) the co-precipitation of CrOx and ZrO2 on SiO2. The SiO2 precursors are TEOS in methods (i) and (ii), and SiO2 produced by calcination of rice husk in (iii). The catalysts are tested in the nonoxidative dehydrogenation of propane in a flow system with a fixed catalyst bed at 500–600°С. The co-precipitation of CrOx and ZrO2 ensures high efficiency of the catalysts. At 500 and 550°C, the most efficient catalyst is CrZr/SiO2 synthesized by depositing CrOx and ZrO2 on SiO2; at 600°C, the best on-stream behavior is exhibited by CrZrSi catalyst synthesized via the simultaneous precipitation of all components. SEM/EDX, XRD, H2-TPR, and Raman spectroscopy are used to show that in the catalysts synthesized via the co-precipitation of CrOx and ZrO2, these components (which form active sites) are uniformly distributed, have close contact, and are adequately dispersed, while Cr6+ is readily reduced to Cr3+ by the hydrogen contained in the reaction medium. [ABSTRACT FROM AUTHOR]

At present, people face the danger of various occupational exposures, resulting in the rapid development of protective composites among which puncture-resistant materials are an essential component. In this article, composites impregnated with polyester polyurethane (TPU)/SiO2 are used to improve static puncture resistance. Different types of TPU and different concentrations of SiO2 in the impregnation solution are selected. The mechanical and wearing-related properties of composites are systematically explored and analyzed. The results show that static puncture resistance and tensile strength are improved after impregnation. Meanwhile, the composites can still maintain a good water-vapor transmission rate. The air permeability, tearing strength, elongation at break and flexibility of the composites decrease slightly. This study provides a novel and feasible strategy to prepare a flexible composite with high static puncture resistance as well as excellent wearability which is a desirable candidate as a garment accessory or gaket protecting the human body from puncture risk. [ABSTRACT FROM AUTHOR]

The influence of the method used for synthesizing ZnO-In2O3 composites (nanopowder mixing, impregnation, and hydrothermal method) on the structure, conductivity, and sensor properties is investigated. With the nanopowder mixing, the size of the parent nanoparticles in the composite remains practically unchanged in the range of 50–100 nm. The impregnation composites consist of 70 nm In2O3 nanoparticles with ZnO nanoclusters < 30 nm in size located on its surface. The nanoparticles in the hydrothermal composites have a narrow size distribution in the range of 10–20 nm. The specific surface of hydrothermal samples is five times higher than that of impregnated samples. The sensor response of the impregnated composite to 1100 ppm H2 is 1.3–1.5 times higher than the response of the mixed composite. Additives of 15–20 and 85 wt.% ZnO to mixed and impregnated composites lead to an increase in the response compared with pure In2O3. In the case of hydrothermal composite, up to 20 wt.% ZnO addition leads to a decrease in response, but 65 wt.% ZnO addition increases response by almost two times compared with pure In2O3. The sensor activity of a hydrothermal composite depends on the phase composition of In2O3. The maximum efficiency is reached for the composite containing cubic In2O3 and the minimum for rhombohedral In2O3. An explanation is provided for the observed effects. [ABSTRACT FROM AUTHOR]

This paper reports the use of naturally available raw material as sugarcane bagasse (SB) to prepare cost-effective activated carbon. Activated carbon preparation from SB by using ZnCl2 was carried out by chemical activation method. The raw bagasse, its char and activated carbon were characterized on the basis of iodine number, carbon, hydrogen, nitrogen analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) surface area to check their effectiveness. During activated carbon synthesis, the impregnation ratio of SB and ZnCl2 was maintained at 1:1–1:3 and activation temperature was in the range of 600–900 °C for 1 h. From the characterization study, the highest iodine adsorption of activated carbon was found to be 1140.69 mg/g with a 1:2 ratio at 900 °C whereas char gives an iodine number of 529.63 mg/g at the same temperature. The BET surface area of raw bagasse, its char and activated carbon (SB-Zn2-900) obtained was 4.30, 514.27 and 1386.58 m2/g, respectively, which shows charrification and chemical activation improves surface area. The optimum ratio of impregnation and activation temperature was found to be 1:2 at 900 °C. In this work, activated carbon was successfully prepared and obtained product has better characteristics than previously reported studies. HIGHLIGHTS Utilization of agricultural waste material for production of value-added material such as activated carbon.; Minimizes the burden of solid waste management.; Prepared activated carbon can be utilized for pollutant removal.; Minimizes water pollution by adsorption.; Can replace expensive commercial activated carbon.;

Products made from powder materials differ in their structure significantly from parts made using traditional manufacturing methods such as rolling, casting, or forging. Particular interest is in parts made by powder metallurgy (PM) based on iron infiltrated with copper (Fe--C -Cu PM). In the first part of this research, analysis of the Fe--C -Cu PM part is performed. Another aspect of this research is an investigation of the post-processing of PM parts, especially using conventional machining such as turning. Accordingly, the second part of this research is directed at studies of technological assurance of Fe--C -Cu PM part in turning. Different structure of PM parts also requires a different approach to their machining which was the main object of this research. In the evaluation of technological assurance, the surface roughness parameters were chosen as the main quality identifying parameters.

ABSTRACT: Introduction. The aim of the research is to study the compressibility of composite materials obtained by varying the degree of impregnation of a non-woven needle-punched cloth with an aqueous dispersion of polyurethane. Materials and research methods. Non-woven needle-punched cloth made of polyethylene terephthalate fibers (TU 6-13-0204077-95-91) with a linear density of 0.33 tex (diameter 20–25 microns) was used as objects of research. For impregnation, an aqueous dispersion of anionic stabilized aliphatic polyethiruretane of the brand IMPRANIL DL 1380 (PRC) with a dry residue of 40% was used. The compressibility of canvases and composite materials was established using the ICH indicator according to GOST 577-68 with an accuracy of measuring the thickness of ± 0.001 mm. Results and discussion. An approach is proposed to establish the relationship between the degree of compressibility of composite materials and the load and to obtain an equation for predicting the degree of compressibility of composite materials from the degree of impregnation and load. Optimal loading conditions of the composite material with a minimum degree of compressibility has been established. Conclusion. The optimal degree of impregnation of a non-woven needlepunched fabric made of polyethylene terephthalate fibers with a diameter of 20–25 microns with polyurethane dispersion is 0.5.

ABSTRACT. Introduction. Impregnation with a new solution based on potassium polysulfide showed excellent results in the hydrophobization of cement stone and cement-sand mortar due to the formation of a nanoscale water-repellent coating on the surface of the pores from sulfur nanoparticles formed as a result of the destruction of the molecule during the drying process. An innovative solution based on potassium polysulfide refers to polysulfur compounds, from which, as a result of the destruction of polysulfide molecules, a nanoscale layer of sulfur particles is formed on the surface. Materials and research methods. Potassium polysulfide solutions of different densities were used for impregnation; the properties of the solutions were tested on cubic samples with a 40 mm edge, made on the basis of cement and cement-sand mortar. Particle characteristics were evaluated using a laser particle size analyzer, an electron microscope and a diffractometer. Results. The analysis showed that the average size of the particles forming the protective coating is 20 nm, they have a spherically symmetric shape and crystallize into an orthorhombic crystal lattice structure. The treatment of concrete with a solution of potassium polysulfide ensures the formation of a coating based on nanosized sulfur on the surface of the pores of the stone, which partially fills the pore space and, being hydrophobic, reduces the water bsorption of samples by 2–3 times, and the water absorption of samples impregnated under vacuum for 0.5 hours, decreases to values of 1.3–1.9%. Results and discussion. Modification of concrete with an impregnating composition developed by us with a solution based on potassium polysulfide The impregnating solution based on potassium polysulfide is stable in the concentration range of 1.15–1.35 g/cm3; upon impregnation, it penetrates into the pore structure of concrete at a level of up to 4 cm or more, depending on the growth and structure of the sample. When the material dries in its pores, sulfur nanoparticles crystallize from the polysulfide solution, partially filling the pore space and forming a protective durable insoluble hydrophobic coating that makes it difficult for water to penetrate into the pores of concrete, but retains its vapor permeability, which is important for wall and facing materials. Conclusions. Impregnation of road building materials and concrete products with a composition based on potassium polysulfide improves their performance properties, increases durability and resistance to weathering, which makes it possible to recommend it for use in the climatic conditions of the Russian Federation.

Article Highlights Thermoplastic impregnations show comparable mechanical performance to conventional thermoset impregnations Efficient thermoplastic impregnations will influence the application breakthrough of textile-reinforced concrete Solids content and material of impregnation play an essential role in mechanical utilization degree of reinforcement

The physical and mechanical properties of thermally modified wood impregnated with linseed oil were investigated to find the relationship between the treatment and the acoustic properties. The samples were impregnated with linseed oil (LO). Heat treatment was performed in an oven at four different temperatures, namely 160, 180, 210, and 240 °C. Statistically, the physical, mechanical, and acoustic properties of the treated wood were significantly intensified as compared to the control samples. The physical properties (water absorption) of the treated wood decreased by 72% as compared to the control group. However, while the increase in both MOR and MOE at 240 °C was 13%, the increase in CS at 240 °C was 7%. As a result of the heat treatment, the porosity increased by 33% as compared to the control group. At 240 °C the maximum SAC value was observed to be 0.71 at 5000 Hz and at 4500 Hz 0.78 and 0.80, respectively. The highest STL value, which was 69.9 dB, was observed at 1540 Hz and 3600 Hz. As a result of improved heat transfer, impregnating samples with LO before thermal modifications was observed to increase the efficiency of thermal modification.

This study aimed to improve some surface properties such as color, gloss, and surface roughness changes of Oriental beech (Fagus orientalis L.) wood impregnated with some water repellent chemicals such as glycerol (GR) and glyoxal (GX) after weathering. Oriental beech wood specimens were impregnated with a 4 % aqueous solution of GR, GX, and a mixture of GR and GX (1:1; weight : weight) (GR+GX) and then exposed to weathering in Muğla Province in Turkey. Results showed that [delta]L* values of all wood specimens were decreased after weathering. Moreover, the decreases in the control specimen were higher than in the impregnated wood specimens. Oriental beech wood specimens showed a greenish and yellowish tendency, giving -[delta]a* and +[delta]b* values, respectively. Total color changes of GR impregnated Oriental beech was the lowest after weathering. The gloss of all Oriental beech test specimens decreased after weathering. The control specimen gave the lowest value in all three surface roughness parameters (Ra, Rz, and Rq) after weathering. Among the impregnated specimens, the groups impregnated with GR had, in general, the highest value in all three roughness degrees and showed the most negative results in surface roughness.

Effects of steam explosion were investigated relative to impregnation of wood. Three types of softwoods [North American spruce (Picea orientalis), Korean pine (Pinus koraiensis), and Japanese larch (Larix kaempferi)] were prepared and subjected to steam explosion treatment. The cross-sectional surfaces of the samples were observed with SEM, and their open-pore and closed-pore porosities were determined using a gas pycnometer. The softwoods were vacuum impregnated using ACQ-2 (Alkaline Copper Quaternary), a commercial preservative. After steam explosion treatment, the impregnation amount increased by 42.9% in the spruce and 155% in the Korean pine. However, there was no significant difference in the Japanese larch. The results from this study indicated that the steam explosion treatment helped to improve open-pore porosity by generating micro-cracks in the cell walls of softwoods, which improved the impregnation process. However, the degree of improvement in impregnation process differed by the species type.

One of the most important industries is the extraction and processing of natural stone, which is characterized by a large number of types of facing stone with a wide color palette, which are known not only in Ukraine, but also in the world. From 255 deposits of facing stone as at 01.01.2021, 137 deposits are being developed, which are represented by such minerals as: granite, granodiorite, enderbite, granosienite, sienite, quartz sienite, monzonite, gabbro, anorthosite, labradorite, sandstone, basalt, marble, marbled limestone, limestone, andesite, tuff. A statistical analysis of the decorative stone market of Ukraine for 2019–2021 was carried out, which showed that in recent years there has been a decline in the volume of decorative stone exports in Ukraine. Every year, Ukraine is increasingly maintaining trade and economic relations in the field of natural stone mining and processing with many countries of the world. In order to reduce the negative effects of global processes, enterprise planning should be carried out through institutionalization, which will allow domestic natural stone companies to become more competitive both in the country and in the global market and have a stronger structure for pandemics and political situations, etc. This is achieved by introducing digital fairs rather than classical commercial methods. Global processes have also shown that, as in other industries, the natural stone industry needs to look for new markets and create alternatives. Sharing risk between alternative markets will strengthen the industry economically. Therefore, by reviewing these issues, increasing the number of companies that have completed their institutionalization and branding in the light of science and technology, as well as entering new markets through new remote marketing methods, will make the industry less affected by any crisis.

This study focuses on the synthetic approach influence in morphostructural features and catalytic performances for Ni/CeO2 catalysts. Incipient wetness impregnation, coprecipitation and nitrate combustion were studied as catalyst preparation approaches, and the materials were then tested at 700 °C for methane dry reforming (MDR). The morphostructural properties of the materials were deeply studied using several techniques, such as temperature programmed reduction (TPR), to investigate reducibility and support-metal interaction, N2 physisorption to evaluate the porosity and the surface area, scanning electron microscopy (SEM) and X-ray diffraction (XRD) to estimate Ni dispersion, and temperature programmed oxidation (TPO) to identify the type and amount of coke formed on catalysts’ surface after reaction. From the data obtained, coprecipitation turned out to be the most suitable technique for this application because this catalyst was able to reach 70% of CO2 conversion and 30% methane conversion, with an H2 yield of 15% and 30% yield of CO at the end of the 30 h test. Moreover, it was also the catalyst with the highest metal dispersion, the strongest interaction with the support, and the lowest coke deposition.

Abstract In this research, oven-dry density, air-dry density, and water absorption levels of Oriental beech treated with flame-resistant chemicals (FRC) and coated with polyurethane/polyure (PU) and epoxy (EP) were evaluated. According to ISO 3129 standard, the experimental specimens were made from Oriental beech wood. Wood specimens were subjected to 3% aqueous solutions of boric acid, borax, a boric acid and borax mixture (1:1; weight: weight), ammonium sulphate, and polyurethane/polyurethane, and epoxy resins before being coated with these substances. Results showed that oven-dry and air-density values of PU coated wood were much higher than EP coated wood. Water absorption (WA) levels of PU coated of wood were lower than EP coated wood. While FRC treated and PU coated wood resulted in lower WA levels than only PU coated wood, FRC treated and EP coated wood resulted in higher WA levels than only EP coated wood.

Impregnated activated carbons (IACs) used in air filtration gradually lose their efficacy for the chemisorption of noxious gases when exposed to humidity due to impregnated metal deactivation. In order to stabilize IACs against aging, and to prolong the filters' shelf life, inorganic phosphate compounds (phosphoric acid and its three salts, NaHPO4, Na2HPO4, and Na3PO4) were used as anti-aging additives for two different chromium-free IACs impregnated with copper, zinc, molybdenum, and triethylenediamine (TEDA). Phosphoric acid, monosodium, and disodium phosphate were found to be very efficient in inhibiting the aging of IACs over long periods against cyanogen chloride (the test agent) chemisorption, with the latter being the most efficient. However, the efficiency of phosphate as an anti-aging additive was not well correlated with its ability to inhibit the migration of metal impregnants, especially copper, from the interior to the external surface of carbon granules. Unlike organic additives, the inorganic phosphate additives did not decrease the surface area of the IAC or its physical adsorption capacity for toluene. Using a phosphate additive in IAC used in collective protection and personal filters can improve the safety of the user and the environment and dramatically reduce the need to replace these filters after exposure to humid environments. This has safety, economic, logistical, and environmental advantages. [ABSTRACT FROM AUTHOR]

The impact of the synthesis method on the structural, textural, and surface properties of the Al 2 O 3 -Ga 2 O 3 sample was investigated, and the adsorbents were evaluated for their adsorptive desulfurization properties. The incorporation of Ga atoms into the Al 2 O 3 framework (via SGM) resulted in an increase in specific surface area and pore volume, but a decrease in average pore size. XRF analysis confirmed Ga loading, while SEM-EDS and STEM-EDS techniques revealed well-distributed elements with irregular spherical morphologies. XRD diffractograms confirmed the formation of γ-Al 2 O 3 , with a slight shift of diffraction peaks due to the presence of Ga (via SGM), suggesting that Ga atoms are part of the structure. The obtained solids exhibit values in the Freundlich equation that indicate a degree of nonlinearity in adsorption for Al 2 O 3 , while Al 2 O 3 -Ga 2 O 3 (SGM) and Al 2 O 3 -Ga 2 O 3 (IM) suggest a possible chemical process and favorable adsorption. The small K F values demonstrate weak adsorption on the adsorbents, which can be explained by sulfur-to-metal interaction, π-complexation, and non-specific interactions such as Van der Waals forces. The adsorbent showed the greatest affinity for BT and the least for DBT. The selectivity order from strongest to weakest adsorption was BT: Al 2 O 3 -Ga 2 O 3 (SGM) > Al 2 O 3 -Ga 2 O 3 (IM) > Al 2 O 3 , and DBT: Al 2 O 3 -Ga 2 O 3 (IM) > Al 2 O 3 -Ga 2 O 3 (SGM) > Al 2 O 3. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department 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.)

The delignification of birch chips during kraft pulping was investigated, targeting both the impregnation and cooking steps. Wood chips were impregnated using white liquor, white liquor + NaCl, water or NaCl aqueous solution. Then, the chips were cooked in batch autoclaves applying the same constant composition cooking conditions for all samples. Pulp and two fractions of black liquor (bulk liquor and centrifuged liquor representing the liquor inside the wood chips and fibers) were collected after different pulping times and analyzed for lignin and carbohydrate content. The dissolved wood components were precipitated from selected samples and characterized with respect to composition, molecular weight distribution and structural motifs. Cooking chemicals in the impregnation liquors led to faster delignification and xylan removal during cooking. Higher contents of lignin and xylan were measured in the lumen than in the bulk. The concentration profiles also showed accumulation of dissolved material in the lumen over time, suggesting significant mass transport limitation from lumen to bulk. Further analysis revealed higher fragmentation/degradation of dissolved material with increasing pulping time and in the bulk when compared to the lumen liquor, as demonstrated by the lower molecular weights and the changes in chemical shifts in the NMR spectra. [ABSTRACT FROM AUTHOR]

CeO2-TiO2 is an important mixed oxide due to its catalytic properties, particularly in heterogeneous photocatalysis. This study presents a straightforward method to obtain 1D TiO2 nanostructures decorated with CeO2 nanoparticles at the surface. As the precursor, we used H2Ti3O7 nanoribbons prepared from sodium titanate nanoribbons by ion exchange. Two cerium sources with an oxidation state of +3 and +4 were used to obtain mixed oxides. HAADF–STEM mapping of the Ce4+-modified nanoribbons revealed a thin continuous layer at the surface of the H2Ti3O7 nanoribbons, while Ce3+ cerium ions intercalated partially between the titanate layers. The phase composition and morphology changes were monitored during calcination between 620 °C and 960 °C. Thermal treatment led to the formation of CeO2 nanoparticles on the surface of the TiO2 nanoribbons, whose size increased with the calcination temperature. The use of Ce4+ raised the temperature required for converting H2Ti3O7 to TiO2-B by approximately 200 °C, and the temperature for the formation of anatase. For the Ce3+ batch, the presence of cerium inhibited the conversion to rutile. Analysis of cerium oxidation states revealed the existence of both +4 and +3 in all calcined samples, regardless of the initial cerium oxidation state. [ABSTRACT FROM AUTHOR]

The paper deals with the methods of modification of polymer composite materials in supercritical fluid medium in order to improve their characteristics. The main advantages and disadvantages of the presented methods are revealed, especially energy efficiency and environmental friendliness of using the supercritical fluids. [ABSTRACT FROM AUTHOR]

Trimetallic Fe-Pd-K/α-Al2O3 catalyst by using ultrasonic impregnation method and adding potassium to bimetallic Fe-Pd/α-Al2O3 catalyst was synthesized. The samples were characterized by BET, XRD, TEM, FESEM-EDX, TPR, NH3-TPD and TGA/DTG analysis. It was found that the number of acidic sites and coke deposition on the surface of the trimetallic catalyst decreased by 52% and 62%, respectively and the particle size distribution was more uniformed compared to the bimetallic one. The impregnation time was reduced from 12 to 1 h, compared to traditional method by using the ultrasonic technique. The trimetallic catalyst was applied in selective hydrogenation of acetylene in excess ethylene while the performance improved and resulted in 52% ethylene selectivity and 64% acetylene conversion. The optimal reaction conditions were found to be acetylene concentration of 1.0 V% and temperature of 60 °C. Under optimal conditions; the yield of the trimetallic catalyst was 1.17 times, compared to the commercial one. [ABSTRACT FROM AUTHOR]