Sol Method Research Articles

The Sol Braiding Method for Handling Thick Hair During Transcranial Magnetic Stimulation: An Address for Potential Bias in Brain Stimulation.

Transcranial Magnetic Stimulation (TMS) is a technique that is frequently utilized in neuroscience for both therapeutic and research purposes. TMS offers critical medical services like treating major depression and is vital in almost every research facility. Because TMS relies on scalp placement, hair is thought to affect efficacy because it varies the distance to the target site. Further, it is presumed that the hair textures and length that are predominantly seen in minoritized persons might pose significant challenges to collecting high-quality data. Here, we present preliminary data demonstrating that TMS may be influenced by hair, particularly in historically underrepresented minoritized groups. The Sol braiding approach is introduced here as an easy-to-learn, quick-to-implement technique that reduces variability in TMS. Compared across nine participants, it was found that the Sol method significantly increased motor evoked potential (MEP) strength and consistency (p < 0.05). By removing the physical hair barrier that impedes direct coil-to-scalp contact, the Sol approach enhances TMS delivery. The MEP peak amplitude and the MEP area under the curve (AUC) were shown to increase as a result. While preliminary, these data are an important step in addressing diversity in neuroscience. These procedures are explained for non-braiding experts.

Electric field emission properties of ZnO/microcrystalline diamond composite structures modified by Cu nanoparticles decoration

ZnO nanorods hold promise as cathode materials for field electron emission (FEE) applications, yet their high work function and wide bandgap can hinder performance. Recent research has focused on utilizing Cu nanoparticles (NPs) to decorate and modify the FEE properties of these nanorods, leveraging Cu's low work function and excellent conductivity. In this study, ZnO nanorods were synthesized on diamond substrates via the sol method to create ZnO/microcrystalline diamond (MCD) composite structures. Subsequently, Cu NPs were decorated onto the nanorods using a gel method. The influence of Cu NP concentration on the organization and FEE performance of the composites was investigated. The decorated of Cu NPs can improve the Fermi energy level of the nanorods, replenish electrons lost on the surface due to oxygen adsorption, and improve the field emission performance. With the increase of doping concentration, Cu NPs increase, and when the doping concentration is 0.5 M, NPs appear agglomeration phenomenon, resulting in that the surface of ZnO nanorods is almost completely covered by bulk Cu NPs, and the field emission performance decreases. The minimum value of the turn-on electric field is 0.48 V/μm and the maximum value of the current density is 1.60 mA/cm2, when the decorated concentration is 0.25 M.

Inorganic hole transport layer for lead free bismuth halide perovskite for photovoltaic device

The finest Hole Transport Layer (HTL) with extraordinary optical and electrical properties are significantly influenced the Power Conversion Efficiency (PCE) of the photovoltaic device. Inorganic hole transport materials exhibit better performance than organic hole transport materials. Herein, we demonstrated that optoelectronic properties of inorganic materials of NiO doped with Cu as Hole Transport Layer (HTL) for Lead free Bismuth halide perovskite solar cell. Solution process method of sol – gel was used to synthesize p-type NiO doped with Cu and yield nano particles of high quality. Cu + doped into Ni2+ sites has improved the crystallization of nanoparticles, carrier mobility and carrier electric properties. Results of the study revealed that the Enhancement of electrical conductivity of about 2 % is obtained for NiO doped with Cu which is ∼1.287 × 10−02 compared to the pristine NiO which is ∼2.655 × 10−03.

A molecular-level kinetic model for the primary and secondary reactions of polypropylene pyrolysis

The environmental pollution caused by waste plastics and their potential of resource recovery are receiving increasing attention. In this study, a molecular level kinetic model was established to simulate the polypropylene pyrolysis based on the SOL method, Poisson distribution model and genetic algorithm, which was simplified and effective without the introduction of extensive chemical databases and stiff differential equations. The automatic generation of complex reaction network was based on the representation of species and reactions at molecular level and the design of 14 reaction rules consistent with the mechanism. The model prediction achieved good agreement with experimental data affected by the primary and secondary reactions, verifying the generalizability of the models. The model prediction according to the kinetic parameters provided guidance for the pyrolysis experiments. In general, the molecular-level model behaves exquisite in the evaluation, validation, and prediction, and can gain an insight into the pyrolysis of polymers.

Performance and mechanism of CO2 reduction by DBD-coupled mesoporous SiO2

Abstract In the process of CO2 reduction with dielectric barrier discharge (DBD)-coupled catalysis, the existing material presents unsatisfactory synergy, such as high cost, complicated preparation processes, and low conversion rates. An inexpensive and environmentally friendly mesoporous SiO2 with different morphologies by gel–sol method was synthesized and then introduced for synergistic conversion of CO2 with DBD. The physicochemical properties of the synthesized mesoporous SiO2 materials were analyzed using X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and Brunauer-Emmett-Teller method, indicated the prepared mesoporous materials manifested large specific surface areas, ordered pore channels and pore size, and good stability. The CO2 reduction performance, CO selectivity, and energy efficiency of DBD alone and DBD-coupled mesoporous SiO2 were investigated at different input powers. The SiO2 prepared with 1.05 g cetyltrimethylammonium bromide addition had the highest activity, in which the conversion of CO2, CO yield and energy efficiency were increased by 56.73, 68.41, and 122.31%, respectively, compared with DBD alone. The primary CO2 conversion mechanism of the mesoporous SiO2-coupled DBD was analyzed. It is shown that the suitable pore capacity structure, the large specific surface area, and the presence of filament discharge within the pore size of suitable mesoporous material can promote the decomposition of CO2 on its surface.

Construction of V2O5-WO3/TiO2 nanocones catalyst layer on SiC ceramic membrane for efficient removal of NO and dust

In this work, TiO2 nanocones grown on SiC membrane was used as the support of V2O5-WO3 species to prepare V2O5-WO3/TiO2@SiC (VWTi(C-X)@SiC) catalytic membrane for dust filtration and NH3-SCR denitration. On account of the large specific surface area, abundant surface acid sites and prominent redox property, the optimized VWTi(C-550)@SiC catalytic membrane shows >90% NO removal efficiency at the temperature of 280–360 °C, which are much higher than VWTi(P-550)/SiC catalytic membrane (TiO2 nanoparticles prepared by traditional vacuum coating titanium sol method was used as the support of V2O5-WO3 species, NO conversion <80% at whole tested temperature). Additionally, VWTi(C-550)@SiC displays superior stability during the SO2 + H2O resistance and 300 h long-term test at 300 °C, and exhibits an excellent dust filtration performance (2.5 μm SiO2 particles interception rate exceeded 99.99%) under all test conditions. More importantly, the structure of nanocones decrease the influence of tensile stresses due to the different thermal expansion coefficients of TiO2 and SiC membranes, which significantly suppress the fall of VWTi catalyst layer from the surface of SiC during pulse-jet cleaning. Among above results, it can be concluded that the optimized VWTi(C-550)@SiC catalytic membrane shows a prosperous application prospect for the simultaneously dust filtration and NH3-SCR denitration of medium–high temperature flue gas.

Excellent microwave absorption of void@carbon@TiO2 cubes by a template sol method

The ingenious design of heterogeneous structures is an effective strategy for developing advanced microwave absorption materials. In this study, high-efficiency void@carbon@TiO2 (void@C@TiO2) cubes were synthesized by a template sol method. Compared with void@carbon (void@C) and void@TiO2 cubes, the void@C@TiO2 cubes/paraffin composites of 2.1 µm edge length show excellent microwave absorption performances (MAPs). When the thickness is 2.1 mm, the minimum reflection loss (RL) of – 69.8 dB is superior to – 31.5 dB of void@C cubes at 4.1 mm and – 3.1 dB of void@TiO2 cubes at 3.7 mm. The effective absorption frequency covers 11.8 GHz (6.2–18.0 GHz, RL below – 10 dB) by matching the coating thickness with 1.7–5.0 mm. The enhanced MAPs originated from the synergistic processes of good impedance matching (|Zin/Z0|) and various microwave dissipation mechanisms, including electrical conduction, interfacial charge accumulation, and defect dipolar polarization. The void@C@TiO2 cubes are a lightweight, easy, environment-friendly, and extendible strategy for microwave absorption applications.

Synergistic effect of Ag and Cu on improving in vitro biological properties of K2Ti6O13 nanowires for potential biomedical applications

The development of novel antibacterial nano-materials with synergistic biological effects has attracted extensive interest of the researchers. In the study, 0.5 mol% Ag and 0.5 mol% Cu co-doped K2Ti6O13 (0.5 Ag-0.5 Cu-KTO) nanomaterial was successfully synthesized using two-step method of sol–gel and hydrothermal synthesis. The crystal structure of 0.5 Ag-0.5 Cu-KTO was the same as that of monoclinic K2Ti6O13. Ag ions and Cu ions were uniformly loaded on K2Ti6O13 by replacing partial Ti ions, so that these antibacterial ions could be slowly released. High specific surface area of 0.5 Ag-0.5 Cu-KTO (337.6 m2 g−1) provided more surface active sites for Ag–Cu doping and adsorption. More negative surface zeta potential (−32.83 mV in phosphate buffer solution and −21.45 mV in physiological saline solution, respectively) would be beneficial to prevent the aggregation of the nanowires in physiological environment. Under the same doping amount, compared to 1.0 mol% Cu doped K2Ti6O13, 0.5 Ag-0.5 Cu-KTO exhibited better antibacterial performance against gram-positive and gram-negative bacteria at only 100 μg ml−1 dose concentration, near to 1.0 mol% Ag doped K2Ti6O13 (1.0 Ag-KTO). And 0.5 Ag-0.5 Cu-KTO showed more excellent biocompatibility than 1.0 Ag-KTO, which was attribute to the introduction of Cu ions effectively decreasing the hemolytic and cytotoxic risks from Ag ions. As expected, the synthesized 0.5 Ag-0.5 Cu-KTO nanowires demonstrated excellent structural stability, high antibacterial activity, good hemocompatibility and cytocompatibility owing to the synergistic effects of Cu and Ag ions. 0.5 Ag-0.5 Cu-KTO nanowires will be a promising antimicrobial candidate for biomedical applications.

Preparation of Self‐Catalyzing Sols in the 40SiO2 – 30FeO – 20FeO – 20CaO – 10Na2O Glass System by Sol‐Gel Method

AbstractIn this research, the self‐catalyzing sol method was used to prepare amorphous glass. In this method, as a result of the reaction between iron nitrate and ethanol, nitrous acid was synthesized. Nitrous acid reduced pH and acted as a catalyst ethanol oxidation to ethanoic acid. Different factors affect the preparation of self‐catalyzing sol and the amount of synthesized acid (aging time, temperature of sol preparation, and ratio of precursor to solvent). It was seen that the aging time had the greatest effect in reducing the pH of the sol. Ethanol oxidation was measured by gas chromatography (GC), and it was observed that approximately 95 % of ethanol was converted to ethanoic acid. The optimum glass was heat treated at different temperatures. Maghemite, hematite, and sodium calcium silicate phases were crystallized. The maximum saturation magnetization of the sample treated at 680 °C was 0.27 emu/g.

Aluminum‐Doped ZnO Weld Silver Nanowires‐Based High Transmittance, Low Sheet Resistance, and Tough Composite Transparent Conductive Films

Herein, silver nanowires (AgNWs) and aluminum‐doped zinc oxide (AZO) are prepared by polyol and gel–sol method, respectively. Then bendable, strong adhesion, flat, and high optical transmittance AgNWs:AZO composite transparent conductive film (TCF) is prepared in an all‐solution method. By spinning the AZO to the upper layer of the AgNW networks and annealing at 120 °C for 20 min, the junctions of the AgNW networks are welded by the capillary force in the solvent evaporation and AZO crystallization process. The sheet resistance of the TCF is as low as 12.9 Ω sq−1 at an optical transmittance of 92.1% (@550 nm), which is comparable to the indium tin oxide film on glass. The root means square roughness is reduced from 30.1 to 8.48 nm to match the criteria as anode for organic light emitting diodes (OLEDs). Furthermore, the adhesion between the AgNW networks and the substrate has been significantly improved. Finally, a flexible green OLED device with AgNW:AZO TCF as the anode is successfully prepared. The maximum luminous intensity of the prepared OLED is 10 060 cd m−2, and the maximum current efficiency is 6.43 cd A−1, which proves the great potential of the film in flexible electronics.

Spraying Fluorinated Silicon Oxide Nanoparticles on CuONPs@CF-PVDF Membrane: A Simple Method to Achieve Superhydrophobic Surfaces and High Flux in Direct Contact Membrane Distillation.

Desalinization of seawater can be achieved by membrane distillation techniques (MD). In MD, the membranes should be resistant to fouling, robust for extended operating time, and preferably provide a superhydrophobic surface. In this work, we report the preparation and characterization of a robust and superhydrophobic polyvinylidene fluoride membrane containing fluoroalkyl-capped CuONPs (CuONPs@CF) in the inner and fluorinated capped silicon oxide nanoparticles (SiO2NPs@CF) on its surface. SiO2NPs@CF with a mean diameter of 225 ± 20 nm were prepared by the sol method using 1H,1H,2H,2H-perfluorodecyltriethoxysilane as a capping agent. Surface modification of the membrane was carried out by spraying SiO2NPs@CF (5% wt.) dispersed in a mixture of dimethyl formamide (DMF) and ethanol (EtOH) at different DMF/EtOH % v/v ratios (0, 5, 10, 20, and 50). While ethanol dispersed the nanoparticles in the spraying solution, DMF dissolved the PVDF on the surface and retained the sprayed nanoparticles. According to SEM micrographs and water contact angle measurements, the best results were achieved by depositing the nanoparticles at 10% v/v of DMF/EtOH. Under these conditions, a SiO2NPs covered surface was observed with a water contact angle of 168.5°. The water contact angle was retained after the sonication of the membrane, indicating that the modification was successfully achieved. The membrane with SiO2NPs@CF showed a flux of 14.3 kg(m2·h)-1, 3.4 times higher than the unmodified version. The method presented herein avoids the complicated modification procedure offered by chemical step modification and, due to its simplicity, could be scalable to a commercial membrane.

A novel, green, cost-effective and fluidizable SiO2-decorated calcium-based adsorbent recovered from eggshell waste for the CO2 capture process

The reduction, storage, and reuse of greenhouse gas carbon dioxide (CO2) is a crucial concern in modern society. Bio-waste adsorbents have recently aroused the investigator's attention as auspicious materials for CO2 capture. However, the adsorption capacity decaying and poor fluidizability during carbonation/calcination cycles of all natural adsorbents used in the calcium-looping process (CaL) are important challenges. The current study explores the performance of a novel SiO2-decorated calcium-based adsorbent recovered from eggshell waste in terms of both CO2 capture capacity and fluidity. Two preparation methods of hydration and sol–gel were used to obtain Ca-based adsorbents with different pore configurations and volumes. Modification of the adsorbents was applied by dry physically mixing with different weight percentages of hydrophobic SiO2 nanoparticles (NPs), in order to maintain stability and fluidity. The adsorbent prepared by the sol–gel method exhibited a fluffier structure with smaller grain sizes and higher porosity than that of prepared by the hydration method, leading to a 6.9 % increase in conversion at the end of the 20th cycle. Also, with the optimal amount of SiO2 nanoparticles, i. e. 7.5 wt%, the amount of CaO conversion obtained by sol–gel derived adsorbent was 27.59 % higher than that by pristine eggshell at the end of the 20th carbonation/calcination cycles. The fluidizability tests showed that the highest bed expansion ratio (2.29) was achieved for sol–gel derived adsorbent in the presence of 7.5 wt% silica nanoparticles which was considerably higher than the amount of 1.8 and 1.6 belonged to sol–gel derived adsorbent and pristine eggshell without silica at the gas velocity of ≈ 6.5 cm/s, respectively. The high adsorption capacity and proper fluidity of this novel and green calcium-based adsorbent promise its wide application.

Investigation of processes of obtaining cerium dioxide sol with polyvinyl alcohol having bioactive properties

Cerium dioxide sols are widely used in photocatalysis, catalysis, medicine and cosmetics. It is believed that sols with a CeO2 size of up to 10 nm have the most active biological properties. The method of sols preparation affects their functional properties. They are usually obtained through the stage of separating the oxide in the solid phase from the solution, which can lead to particle agglomeration, and then transferring the oxide to a colloidal solution under the action of various stabilizers. In this study, we propose the method of CeO2 sol obtaining without step of solid phase oxide separation. The stabilizer (polyvinyl alcohol (PVA)) is present at the stage of formation of weakly aggregated CeO2 nanoparticles from cerium(III) salt with an ammonia and hydrogen peroxide solution. Using IR, UV spectroscopy, viscometry and titration it was found that H2O2 eventually oxidizes Ce(III) in solution to Ce(IV) and does not oxidize PVA. The intermediate formed after the addition of ammonia solution to cerium(IV) salt has the composition Ce(ООН)3OН⋅nH2O, which is confirmed by the data of proton magnetic resonance, weight and thermal analyses. The process of CeO2 sol formation stabilized by PVA goes through the stages of Ce(ООН)3ОН dissolution accompanying with an endothermic effect, followed by decomposition. Peroxide compounds in the solid phase are stable in air up to 90–100 °C. The prepared sol has the composition CeO2–PVA–ammonium nitrate, exhibit antioxidant properties, is not a nutrient medium for E. Coli and S. Aureus and is capable to form a calcium-phosphate layer on its surface from a model solution of SBF.

Hydrothermal synthesis of monoclinic zirconia sol

AbstractIn this study, we demonstrate a synthetic method of zirconia sol using ZrO(NO3)2·xH2O as Zr4+ precursor, tetramethylammonium hydroxide as mineralizer, and oxalic acid as a complexing agent. X‐ray diffraction, transmission electron microscopy, Raman spectroscopy, and UV–vis adsorption spectroscopy were used to characterize the nanocrystals. The effect of oxalic acid content on the growth of zirconia nanocrystals was investigated. Zirconia sol cannot be synthesized without oxalic acid. The oxalic acid content has no obvious effect on the phase formation of monoclinic zirconia. The transparent and monoclinic zirconia sol with particle size &lt;10 nm was synthesized. This provides a new hydrothermal system for the synthesis of zirconia sol.

Application of Polymer Nanocolloid Preparation in Stability Analysis of Motion Mechanics

Nanomaterials are widely used in various fields because of their own advantages. When the particle size of the material is reduced to the nanometer level, it will lead to new characteristics of acoustic, optical, electrical, magnetic, and thermal properties. This will greatly enrich the research content of the material and is expected to get new uses. Therefore, the preparation technology of nanomaterials is one of the current research hotspots and has broad application prospects. At present, the most commonly used preparation techniques are hydrothermal method and sol-gel method, but not all crystals grow in a hydrothermal environment, so this paper adopts the sol-gel method for preparation. However, in the preparation of nanocolloids, agglomeration often occurs between colloidal nanoparticles. In order to avoid the agglomeration between particles, this paper adopts an appropriate method to disperse the particles. In order to further explore the stability of nanocolloids, the colloidal film material prepared by the cadmium sulfide (CdS) sol method was used as the research sample. It also proposes a sol preparation method incorporating ultrasonic waves and further discusses the kinetic characteristics. The research results show that the sedimentation velocity of 1 nm cadmium sulfide nanocolloids in water is 1.3 × 10−12 (m/s) prepared by colloid of cadmium sulfide.

Transparent superhydrophobic film with anti-fouling and anti-scaling ability by facile method of dip-coating SiO2 Sol

In the past decades, the studies of materials with transparency and durable superhydrophobicity have captured much attention because of the versatile uses in outdoor glass wall, automobile windshield and solar panel. In this paper, a superhydrophobic and transparent SiO2 film with transmittance over 44% was obtained on glass substrate with a facile method of dip-coating without further modification. The contact angle and sliding angle of water droplet on the superhydrophobic film is 163.1° and 4°, respectively. The results reveal the performance of superhydrophobicity originates from the synergistic effects of rough SiO2 structures and hydrophobic alkyl with low surface energy. The SiO2 coating exhibits self-cleaning ability, anti-fouling property and anti-scaling performances. Furthermore, the SiO2 coatings have good thermal stability and resistance ability to acid and base. The techniques adopted here have the advantage of simple process, low cost and fluorine-free treatment, which may provide an useful reference for the preparation of transparent and superhydrophobic film in practice.

Solution combustion derived oxygen vacancy-rich Co3O4 catalysts for catalytic formaldehyde oxidation at room temperature.

Fabricating abundant oxygen vacancies is crucial for non-noble metal oxides to catalyze formaldehyde (HCHO) oxidation at room temperature. Here, a simple one-pot preparation method via solution combustion was found to produce oxygen vacancy-rich Co3O4 catalysts, avoiding delicate defect engineering. The catalyst was evaluated to result in 52% HCHO conversion in a dynamic flow reaction with ∼6 ppm HCHO, which was higher as compared to some other Co3O4 catalysts prepared in three methods of sol–gel, deposition precipitation and thermal decomposition. The optimal catalyst also exhibited high durability with steady HCHO conversion (∼47%) for more than 50 h. The catalyst characterizations revealed that the explosive solution combustion brought out two particular features of Co3O4, namely, the porous network structure with nano-holes and the abundant oxygen vacancies. The latter was demonstrated to increase the reactive oxygen species and to improve the reducibility and the oxygen transport capacity of Co3O4. The two features and the derived properties are beneficial to the activity and durability of Co3O4. The solution combustion method can serve as a simple and feasible way to fabricate abundant oxygen vacancies to provide room-temperature activity of Co3O4 for HCHO elimination at room temperature.

Structure, magnetic properties and microwave absorption properties of NdFe1-xNixO3

In this paper, a high-purity NdFe 1-x Ni x O 3 perovskite-type material was prepared by a simple sol method. At the same time, adjust the substitution content of nickel to achieve the purpose of adjusting the dielectric properties and magnetic properties. According to the respective instruments, as Ni is substituted into the NdFeO 3 , the crystal microstructure will change to a certain extent, and there is a certain causal relationship between the magnetic properties and the bonding. Therefore, by adding a certain amount of nickel, the dielectric properties and magnetic properties can be adjusted to a certain balance point. NdFe 1-x Ni x O 3 material has excellent microwave absorption performance. When x = 0.2, the minimum reflection loss value is −49.32, and the corresponding impedance matching value is 1, and the effective bandwidth is 2.2 GHz when the thickness is 5.0 mm. The material that adjusts the perovskite structure by Ni element is beneficial to make the microwave absorption peak move from high frequency to low frequency, which has a wider application range and is closer to civil, commercial, military and aerospace.

A highly transparent and photothermal composite coating for effective anti-/de-icing of glass surfaces.

Anti-/de-icing of glass surfaces is of great importance in present daily life. The long-standing challenge in this field is largely due to the lack of stable multifunctional coatings that can be conveniently and economically constructed on the glass surface, and more importantly, are capable of retaining the original transparency of glass ranging from the visible to the near infrared spectrum. Herein, a direct spraying sol method on the glass surface to prepare a highly transparent and photothermal composite coating is reported. Such multifunctional coating of Cu7S4 nanoparticles/organo-silicone sols has displayed a good photothermal conversion property and hydrophobic property and therefore yields excellent anti-icing and self-melting ice properties. The condensation time of water droplets can be extended to 86 s even at −10 °C, which is 3.42 times delayed relative to ordinary blank glass. And the adhesion strength of ice is largely reduced to 72 KPa, which is as low as ∼1/3 that of ordinary glass. Meanwhile, the subcooling of adhering droplets is reduced to −12 °C under one solar illumination condition and exhibits a rapid de-icing capability. More impressively, the prepared functional coating glass shows an outstanding transmittance of more than 75% in the visible region, while it is over the minimum glass transmittance limit allowed by Safety Standards for Glass (GB9656-2016, China). In addition, the multifunctional photothermal glass coating exhibits good physical/chemical stability, which facilitates the long-term application of the coating in different environments.

Enhancement Of Aqua Scourings Technology From Petrochemical

Currently, there are sorbents, both natural and modified, that allow you to simultaneously purify water from various pollutants, for example, from ions of heavy metals and petrolium products. A new modified sorbent was obtained using the sol method. This sorbent is granules of co-precipitated magnesium and aluminum hydroxides with a layered structure. To characterize the structure of the systems under study, analysis was carried out. The study of the mechanism of interaction of the sorbent with heavy metal ions was carried out by studying the chemical composition of the sorbent and the state of adsorbed ions by spectroscopy analysis. It is concluded that the modified inorganic sorbent based on magnesium and aluminum hydroxides has a number of distinctive features and advantages over other filter materials.