Precipitation Method Research Articles

Hydroxypropyl methylcellulose/sodium alginate/hydroxyapatite nano biomaterial enriched with zinc to promote bone tissue augmentation

Bone is a dynamic connective tissue that provides structural support and locomotion to human physiology. Severe bone degeneration can occur in cases of trauma, infections, genetic disorders, tumors, and hormonal imbalances. This leads to a demand for scaffolds and composites to enhance bone tissue regeneration. The present study aimed to develop a composite material using hydroxypropyl methylcellulose and sodium alginate in combination with hydroxyapatite. The composite was doped with zinc and developed into a nanocomposite using ionic gelation and solvent precipitation methods. The prepared nanocomposite was characterized by scanning electron microscopy, atomic force microscopy, dynamic light scattering, FTIR, and XRD studies. In vivo pharmacological studies were conducted to establish the bone targeting and bone tissue regeneration efficacy of the developed nanocomposite. The nanocomposite was checked for cell toxicity by performing an MTT assay using MG63 cell line and the molecular mechanism of targeting efficiency was assessed by an in silico evaluation method. The results of the study confirmed the polymeric interlinking in the nanocomposite and the successful preparation of a composite material using biodegradable excipients. SEM and AFM studies indicated that the nanocomposite was within the 80–200 nm size range. MTT assay indicated that the developed nanocomposite was not cytotoxic and well tolerated by the MG63 cell line. In vivo, studies in validation with molecular docking evaluation suggested that the nanocomposite was effectively targeted to the bone and enhanced the bone density by blocking Farnesyl Diphosphate Synthetase (FDPS) in the mevalonate pathway which is essential for inhibiting the osteoclastic activity and promoting osteogenesis.

PVA-assisted preparation of Mg(OH)2/MgO nanostructures from seawater bittern through precipitation method

PVA-assisted preparation of Mg(OH)2/MgO nanostructures from seawater bittern through precipitation method

Investigating the physicochemical, rheological, and sensory properties of low‐fat mayonnaise prepared with amaranth protein as an egg yolk replacer

AbstractThis study investigated the possibility of using amaranth protein isolate (API) as a plant‐based substitute for egg yolk (EY) in the preparation of low‐fat mayonnaise (LFM). The alkali extraction/acidic precipitation method was used to isolate amaranth protein; its functional properties were then studied. The results showed that besides its great water and oil absorption capacities, API had better emulsifying capacity and significantly higher (p < .05) emulsion stability at pH 2.0 than alkali pH values. Five mayonnaise samples with different API/EY combination ratios (%) (i.e., 0/0.75, 0.25/0.5, 0.375/0.375, 0.5/0.25, and 0.75/0) were prepared. The color, emulsion stability (ES), freeze–thaw stability (FTS), droplet size, structure, rheology, and sensory properties of samples were examined. API replacement showed no adverse effects on the L* value, ES, and sensory attributes (p > .05). Low API concentrations (0.25% and 0.375%) significantly (p < .05) increased the droplet size and decreased the FTS of LFM emulsion. High API concentrations (0.5% and 0.75%) had no significant effect (p > .05) on droplet size and formed emulsions with more tightly packed oil droplets. The Cross model was chosen best to describe the flow behavior of LFM samples (R2 = 0.99). The sample with 0.75% API had significantly (p < .05) the highest values of ηo (zero‐shear viscosity) and λ (relaxation time), indicating greater interaction between the emulsion particles. All samples showed a weak gel structure (G' > G"). In conclusion, API can be considered an appropriate substitute for EY in LFM production, which can benefit human health and offer a new strategy for preparing vegan products.

Evaluation of the content of polyphenols, flavonoids and tannins, the antioxidant capacity, and the antimicrobial activity of different organic and aqueous fractions of stems of Retama monosperma

Retama monosperma is an endemic plant of the Mediterranean region that has been traditionally used in folk medicine to treat various ailments. It contains a variety of bioactive phytochemicals and exhibited several biological activities. This study aimed to assess the phytochemical screening, total phenolic, total flavonoid, and total tannin compounds, as well as the antioxidant capacity and antimicrobial activity. The phytochemical screening involved color reactions, characteristic reagents, and precipitation methods. Total phenolic, flavonoid, and tannin compounds were quantified using colorimetric methods across four fractions. Antioxidant capacity was assessed using 2,2-Diphenyl-1-picrylhydrazyl radical scavenging, ferric reducing antioxidant power, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging, and phosphomolebdenum assay. The antimicrobial activity was evaluated through disc diffusion method and the microdilution assay. Qualitative phytochemical tests revealed the presence of flavonoids, tannins, terpenoids, alkaloids, and sterols. Quantification of total phenolic, flavonoid, and tannin compounds confirmed the richness of polyphenolic compounds in all fractions. The antioxidant capacity measurements revealed that the ethanol fractions exhibited the highest antioxidant capacity in 2,2-Diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power assays, and phosphomolebdenum assay. Conversely, the aqueous fraction showed highest activity in the 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay. Regarding antimicrobial activity, the ethyl acetate fraction demonstrated superior efficacy against Staphylococcus aureus, and Bacillus cereus. These findings suggest that R. monosperma could serve as a valuable source of antioxidant and anti-infective phytocompounds.

Method development and validation for the estimation of gedatolisib in mouse plasma by tandem mass spectrometry and its application to pharmacokinetics studies.

A simple and a sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of gedatolisib in mouse plasma. The extraction technique involved a simple precipitation method to extract gedatolisib and idelalisib (internal standard) from mouse plasma. A clean chromatographic separation of gedatolisib and the internal standard was achieved on an Atlantis dC18 column using an isocratic mobile phase (10mm ammonium formate and acetonitrile; 30:70% v/v, both supplemented with 0.1% formic acid) delivered at a flow rate of 0.7ml/min. The total run time was 2.0min, and gedatolisib and idelalisib were eluted at 0.80 and 0.95 min, respectively. Gedatolisib was monitored at m/z 616.40 → 488.20 and idelalisib at 416.05 → 176.10. All the required parameters for the method validation were performed as per US Food and Drug Administration guidelines, and the results were within the acceptance criteria. The method was accurate and proved to be precise at a linearity range of 1.33-2667 ng/ml. The accuracy for gedatolisib in mouse plasma was in the ranges 0.99-1.06% (intra-day) and 0.96-1.04% (inter-day). Gedatolisib appeared to be stable in a series of stability conditions. Gedatolisib showed a good intravenous profile when administered through a solution formulation.

Novel EDTA mediated ethanol protein precipitation method and the application for polysorbate quantification in high protein concentration biopharmaceuticals

Non-ionic surfactants such as Polysorbate 20/ 80 (PS20/ PS80), are commonly used in protein drug formulations to increase protein stability by protecting against interfacial stress and surface absorption. Polysorbate is susceptible to degradation which can impact product stability, leading to the formation of sub-visible and/or visible particles in the drug product during its shelf-life, affecting patient safety and efficacy. Therefore, it is important to monitor polysorbate concentration in drug product formulations of biotherapeutic drugs. The common method for measuring polysorbate concentration in drug product formulations uses mixed mode ion exchange reversed phase HPLC (MAX) coupled to evaporative light scattering detection (ELSD). However, high protein concentration can adversely impact method performance due to high sample viscosity, gel formation, column clogging, interfering peaks and loss of accuracy. To overcome this, a new method was developed based on EDTA mediated ethanol protein precipitation (EDTA/EtOH). This method was successfully implemented for the analysis of polysorbate in antibody formulations with wide range of protein concentration (10–250 mg/mL).

Control of urease activity in enzyme-induced carbonate precipitation method for soil improvement at high temperatures

Control of urease activity in enzyme-induced carbonate precipitation method for soil improvement at high temperatures

Synthesis and performance study of novel antibacterial and anticorrosive polyurethane IPN

Polyaniline has been extensively used for the corrosion protection of polymeric materials. However, there have been few studies on its combined antimicrobial activity when used in combination with silver molybdate. In this study, we synthesized silver molybdate (Ag2MoO4) crystals using a homogeneous precipitation method. Polyaniline-dodecylbenzenesulfonic acid/castor oil(PANI-DBSA/CO) mixtures were prepared in an encapsulated state by in situ polymerisation. Subsequently, PANI/Ag2MoO4-PU interpenetrating polymer network(IPN) composite coatings(P/A-PU) were produced by dispersing Ag2MoO4 and PANI-DBSA/CO in polyurethane using ultrasonic dispersion. The composite coatings were characterized using Fourier transform infrared spectroscopy(FTIR), X-ray diffraction analysis(XRD), and transmission electron microscopy(TEM). The study confirmed that composite coatings with uniformly dispersed nanoparticles of PANI and Ag2MoO4 encapsulated by CO and epoxy resin E-44 grease exhibit improved physico-mechanical characteristics. The research also evaluated the effect of nanoparticles on the corrosion behaviour of the coatings using electrochemical impedance spectroscopy and kinetic potential polarisation experiments. The study investigated the antimicrobial properties of P/A-PU composite coatings on Escherichia coli(E.coli) and Staphylococcus aureus(S.aureus) by conducting bacterial growth curves, protein leakage, and fluorescence staining experiments. The aim was to establish a causal connection between the coated surfaces and the observed antimicrobial properties. The study demonstrated that incorporating IPN of polyaniline polyurethane into the coating composites improved their anticorrosive properties. Furthermore, the addition of silver molybdate at a mass ratio of 0.3 % resulted in a remarkable 99 % antimicrobial activity against E.coli and S.aureus.

Polycaprolactone Microsphere‐Encapsulated Fluconazole‐Loaded Zinc Oxide and Hydroxyapatite Nanocomposites for Enhanced Biological Performance

AbstractOsteomyelitis (OM), a debilitating disease caused by a microbial infection of the bones, continues to pose a formidable obstacle for orthopedic surgeons. The conventional methods for the prevention and treatment of OM are insufficient. In this research work, we developed a strategic green nanostructure using the antifungal drug Fluconazole (FCZ)‐assimilated zinc oxide nanoparticles (ZnO‐NPs) and hydroxyapatite (HAp) nanostructures as filler and hydrophobic polycaprolactone (PCL) as matrix by a solution‐based chemical method. The ceramic carrier‐like nanostructures ZnO and HAp were synthesized by the in situ precipitation method. The physicochemical characterization of the prepared polymer‐coated drug ceramic nanocomposite (FCZ‐ZnO‐HAp‐PCL) was achieved using Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), particle size distribution (PSD), X‐ray diffraction (XRD), and Energy‐dispersive X‐ray (EDX) analysis. Furthermore, the biocompatibility and anticancer activity of the nanocomposite were explored by an MTT assay study. Successfully synthesized FCZ‐ZnO‐HAp‐PCL nanocomposite exhibited profound antimicrobial activity against targeted microbe species and potential cytotoxicity towards MCF‐7 human breast adenocarcinoma cell lines, which may be potentially used for the treatment of OM and prospective infections.

The comparative study of Ti-bearing oxides introduced by different methods

Abstract The Ti-bearing oxides are introduced into HRB400 steel melt through external addition method (EAM, TiO2) and internal precipitation method (IPM, Ti alloy) using a vacuum induction furnace, respectively. For each experiment, the instantaneous evolution of oxide properties was investigated through the analysis of intermediate samples. For the EAM method, it was found that the titanium content gradually increased with increase in the treatment time. Similar increasing trend is also observed for Ti-bearing oxide properties, such as the number density and normalized titanium content. These phenomena are totally different from those in the IPM intermediate samples, in which both Ti content and Ti-bearing oxide features show rapid increase, reaching saturation at 1 min after the addition of Ti alloy, and remain relatively stable thereafter. This comparison hints that after TiO2 addition, they first dissolve in molten steel, then decompose, and finally again form Ti-bearing oxides. Furthermore, in the case of similar titanium content, EAM intermediate samples exhibit higher Ti-bearing oxide number density and higher normalized titanium content compared to IPM samples. After heat treatment, the intragranular ferrite nucleation was observed in cast sample of EAM, which was induced by the introduced Ti-bearing oxides.

Equine bone marrow MSC-derived extracellular vesicles mitigate the inflammatory effects of interleukin-1β on navicular tissues in vitro.

Safe, efficacious therapy for treating degenerate deep digital flexor tendon (DDFT) and navicular bone fibrocartilage (NBF) in navicular horses is critically necessary. While archetypal orthobiologic therapies for navicular disease are used empirically, their safety and efficacy are unknown. Mesenchymal stem cell-derived extracellular vesicles (EV) may overcome several limitations of current orthobiologic therapies. To (1) characterise cytokine and growth factor profiles of equine bone marrow mesenchymal stem cell (BM-MSC)-derived extracellular vesicles (BM-EV) and (2) evaluate the in vitro anti-inflammatory and extracellular matrix (ECM) protective potentials of BM-EV on DDFT and NBF explant co-cultures in an IL-1β inflammatory environment. In vitro experimental study. Cytokines (IL-1β, IL-6, IL-10, IL-1ra and TNF-α) and growth factors (TGFβ1, VEGF, IGF1 and PDGF) in equine BM-EV isolated via ultracentrifugation and precipitation methods were profiled. Forelimb DDFT and NBF explant co-cultures from seven horses were exposed to media alone, or media containing 2 × 109 ± 0.1 × 109 particles/mL or 10 μg/mL BM-EV (BM-EV), 10 ng/mL interleukin-1β (IL-1β), or IL-1β + BM-EV for 48 h. Co-culture media IL-6, TNF-α, MMP-3, MMP-13 concentrations and explant sulphated glycosaminoglycan (sGAG) content were quantified. IL-6, IGF1 and VEGF concentrations were 102.1 (37.61-256.2) and 182.3 (163.1-226.3), 72.3 (8-175.6) and 2.4 (0.1-2.6), 108.3 (38.3-709.1) and 211.4 (189.1-318.2) pg/mL per 2 × 109 ± 0.1 × 109 particles/mL or 10 μg/mL 10 μg of BM-EV isolated via ultracentrifugation and precipitation methods, respectively. Co-culture media MMP-3 in BM-EV- (p = 0.03) and BM-EV + IL-1β-treated (p = 0.01) groups were significantly lower than the respective media and IL-1β groups. DDFT explant sGAG content of BM-EV (p = 0.003) and BM-EV + IL-1β groups were significantly higher compared with IL-1β group. Specimen numbers are limited, in vitro model may not replicate clinical case conditions, lack of non-MSC-derived EV control group. Equine BM-EV contains IL-6 and growth factors, IGF1 and VEGF. The anti-inflammatory and ECM protective potentials of BM-EV were evident as increased IL-6 and decreased MMP-3 concentrations in the DDFT-NBF explant co-culture media. These results support further evaluation of BM-EV as an acellular and 'off-the-shelf' intra-bursal/intrasynovial therapy for navicular pathologies.

High Quality and Purified DNA Extraction Protocol from Transplastomic Potato Lines by Cetyltrimethylammonium Bromide (CTAB)-Based Method

For the advanced molecular techniques high quality and pure DNA is important requirement where a quick and cost-effective extraction method is a crucial factor. Commonly, prolong incubation period, multiple precipitations, and highly expensive commercial kits are remaining basic barrier to introduce swift and easiest method of DNA extraction from transgenic plants. Non-cellulose components present in the leaf and elevated level of starch content as well as protein content also makes this extraction procedure challenging and difficult. Present study was conducted to establish a unique DNA isolation method with some modification of existing CTAB method to ensure high-quality and purified genomic DNA from the potato plants. Through the implementation of solution based and selective DNA precipitation method, 100 mg of potato leaves from every transplastomic potato lines was applied to extract genomic DNA. Ethanol (70%) was used as elution buffer where maximum DNA yield was 3415.500 ng/µl and the ranges of DNA purity (A260/A280 nm) was recorded as 1.954-2.048, respectively. Compared to existing methods, this modified CTAB mediated procedure is swift (at least one hour can be saved ) and proficient enough for high quality DNA yield, free from the selective precipitation, regents and laboratory equipment’s are cost-effective and non-toxic to human health.

Semi‐aromatic polyamide containing ether bond/hydroxyapatite composites: Preparation, structure and cytocompatibility

AbstractIn this work, semi‐aromatic polyamide containing ether bond (PAE10T) was synthesized through nucleophilic substitution reaction using 1, 10‐N, N′‐bis(4‐fuorobenzamide) decane (BFBD) and hydroquinone (HQ) as the raw materials. And then the composites hydroxyapatite/semi‐aromatic polyamide (40%HA‐PAE10T and 60%HA‐PAE10T) were prepared by chemical precipitation method. Mechanical, SEM, FT‐IR, XRD, DSC, TGA and bioactivity tests were performed to characterize the structure, morphology, thermal and mechanical properties of PAE10T and its composites. Mechanical tests revealed that the difference of HA in weight played an important role in mechanical performance of the composites. Furthermore, in comparison with PAE10T, the 60%HA‐PAE10T showed the highest enhancement in compressive strength (133 MPa) at 75.9%, and the 40%HA‐PAE10T given expression to the best increase in bending strengths (97 MPa) at about 18.4%. The 40%HA‐PAE10T and 60% HA‐PAE10T exhibited the mechanical performances closed to the cortical bone of human. After 28 days of dip in the phosphate buffer saline (PBS), PAE10T, and its composites showed satisfactory stability. The cell culture results showed all composites gad good cytocompatibility, cells attached on the materials well with excellent morphology. All the experimental results showed that the composites were expected to have a good application in the field of compact bone repair.

Enhancing osteoblast proliferation and bone regeneration by poly (amino acid)/selenium-doped hydroxyapatite

Among various biomaterials employed for bone repair, composites with good biocompatibility and osteogenic ability had received increasing attention from biomedical applications. In this study, we doped selenium (Se) into hydroxyapatite (Se-HA) by the precipitation method, and prepared different amounts of Se-HA-loaded poly (amino acid)/Se-HA (PAA/Se-HA) composites (0, 10 wt%, 20 wt%, 30 wt%) by in-situ melting polycondensation. The physical and chemical properties of PAA/Se-HA composites were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and their mechanical properties. XRD and FT-IR results showed that PAA/Se-HA composites contained characteristic peaks of PAA and Se-HA with amide linkage and HA structures. DSC and TGA results specified the PAA/Se-HA30 composite crystallization, melting, and maximum weight loss temperatures at 203.33 °C, 162.54 °C, and 468.92 °C, respectively, which implied good thermal stability. SEM results showed that Se-HA was uniformly dispersed in PAA. The mechanical properties of PAA/Se-HA30 composites included bending, compressive, and yield strengths at 83.07 ± 0.57, 106.56 ± 0.46, and 99.17 ± 1.11 MPa, respectively. The cellular responses of PAA/Se-HA composites in vitro were studied using bone marrow mesenchymal stem cells (BMSCs) by cell counting kit-8 assay, and results showed that PAA/Se-HA30 composites significantly promoted the proliferation of BMSCs at the concentration of 2 mg ml−1. The alkaline phosphatase activity (ALP) and alizarin red staining results showed that the introduction of Se-HA into PAA enhanced ALP activity and formation of calcium nodule. Western blotting and Real-time polymerase chain reaction results showed that the introduction of Se-HA into PAA could promoted the expression of osteogenic-related proteins and mRNA (integrin-binding sialoprotein, osteopontin, runt-related transcription factor 2 and Osterix) in BMSCs. A muscle defect at the back and a bone defect at the femoral condyle of New Zealand white rabbits were introduced for evaluating the enhancement of bone regeneration of PAA and PAA/Se-HA30 composites. The implantation of muscle tissue revealed good biocompatibility of PAA and PAA/Se-HA30 composites. The implantation of bone defect showed that PAA/Se-HA30 composites enhanced bone formation at the defect site (8 weeks), exhibiting good bone conductivity. Therefore, the PAA-based composite was a promising candidate material for bone tissue regeneration.

Improved piezo-photocatalysis for aquatic multi-pollutant removal via BiOBr/BaTiO3 heterojunction construction

Piezo-catalysis is a green and effective method for degrading rich and obstinate molecules in wastewater. Yet, the piezo-catalytic performance of frequently-used barium titanate (BTO) is still limited for practical applications, thus it is crucial to construct high-efficiency BTO-based catalysts. Herein, BiOBr/BTO heterojunction-based piezo-photocatalysts were successfully prepared using the chemical precipitation method, and an internal electric field was established via ultrasound to promote the separation of photogenerated electron-hole pairs through the synergistic effect of piezocatalysis and photocatalysis. Transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy were utilized to characterize the heterojunction. The degradation performance of Rhodamine B (RhB) by BiOBr/BTO is the best among various pollutants, giving a reaction rate constant up to 20.839 × 10−2 min−1, exceeding numerous previously reported catalysts. In addition, the piezo-photocatalytic reaction rate of BiOBr/BTO for Methyl Orange was 9.298 × 10−2 min−1, ≈ 3.3 times than those of pure BTO (2.806 × 10−2 min−1), and also ≈ 15.9 times and 3.3 times than those of single photocatalysis (0.585 × 10−2 min−1) or piezocatalysis (2.848 × 10−2 min−1). Importantly, the BiOBr/BTO heterojunction demonstrates excellent catalytic degradation performance for a broad range of pollutants (e.g., dyes and antibiotics) and their mixtures, as well as favorable cycling stability and repeatability with changed environmental conditions, displaying applicability in actual wastewater treatment. The possible degradation pathways of RhB were analyzed by liquid chromatography-mass spectrometry. The present work supplies a feasible strategy for the preparation of high-efficiency piezo-photocatalytic BTO-based heterojunctions, which can guide other composites for environmental remediation.

Anilato-Based Coordination Polymers with Slow Relaxation of the Magnetization: Role of the Synthetic Method and Anilato Ligand.

We have prepared and characterized three coordination polymers formulated as [Dy2(C6O4Cl2)3(fma)6] ⋅ 4.5fma (1) and [Dy2(C6O4X2)3(fma)6] ⋅ 4fma ⋅ 2H2O with X=Br (2) and Cl (3), where fma=formamide and C6O4X2 2-=3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone dianion with X=Cl (chloranilato) and Br (bromanilato). Compounds 1 and 3 are solvates obtained with slow and fast precipitation methods, respectively. Compounds 2 and 3 are isostructural and only differ in the X group of the anilato ligand. The three compounds present (6,3)-gon two-dimensional hexagonal honey-comb structures. Magnetic measurements indicate that the three compounds show slow relaxation of the magnetization at low temperatures when a continuous magnetic field is applied, although with different relaxation times and energy barriers depending on X and the crystallisation molecules. Compounds 1-3 represent the first examples of anilato-based lattices with formamide and field-induced slow relaxation of the magnetization.

Modification of physicochemical properties of chitosan to improve its pharmaceutical and agrochemical potential applications

Chitosan has received much more attention as a functional biopolymer with applications in pharmaceuticals, agricultural, drug delivery systems and cosmetics.The objectives of present investigation were to carry out modification of chitosan for enhancement of aqueous solubility, which will impart increased solubility and dissolution rate of poorly soluble drug itraconazole (ITZ) and also evaluate the modified chitosan for soyabean seed germination studies.The modification of chitosan was accomplished through the antisolvent precipitation method; employing five carboxylic acids. The resulting products were assessed for changes in molecular weight, degree of deacetylation, solubility and solid state characterization. Subsequently, the modified chitosan was complexed with itraconazole using the co-grinding technique. The prepared formulations were evaluated for solubility, FTIR (Fourier-transform infrared spectroscopy), PXRD (Powder X-ray diffraction), in-vitro dissolution studies. Furthermore the effect of modified chitosan has been evaluated on soybean seed germination.Results demonstrated that, modified chitosan improves self and solubility of itraconazole by six folds. As there was increased degree of deacetylation of chitosan leads to improvement in solubility. The results of FTIR showed the slight shifting of peaks in co-grind formulations of itraconazole. Formulations showed reduction in crystallinity of drug which leads to enhancement in dissolution rate as compared to pure itraconazole. Retention of property of seed germination was observed with modified chitosan at optimum concentration of 3 % w/v, with benefit of enhanced aqueous solubility of chitosan.This positive result paves the way for the advancement of pharmaceutical and agrochemical products employing derivatives of chitosan.

Experimental Behavior of Solar Still Using Mixed Oxides Mn-Fe/Silicona Resin Composite as Selective Solar Absorber

The optical properties of a black pigment of mixed Mn-Fe oxides synthesized by the precipitation method, dispersed in silicone resin in different concentrations as well as different thicknesses of float glass with 0.1% of Fe2O3 for use in the construction of a two-slope passive solar still. Regarding the pigments, the spectral absorbance and emittance were evaluated, the x-ray diffraction patterns were obtained to know their crystalline structure and their morphology was studied through surface profilometry, in addition the spectral transmittance for the different samples of float glass was evaluated. With the previous information, both the absorbing surface and the condensers were optimized to propose the best design of the solar still. The hybrid material used as a selective coating in the still, which corresponds to 2.3% Mn-Fe mixed oxides, exhibited a high solar absorbance of 91.82% and a relatively low infrared thermal emission, less than 57.22%, as well as good stability to the corrosive and hot environment of the solar still, in addition to great durability over time, real operating conditions. The float glass with the highest transmittance corresponds to a thickness of 3 mm and an average transmittance of 82.57%. The built prototype was characterized by obtaining the temperature profiles of the absorber, water column and condensers, thermal efficiency, production and water quality. The prototype has a thermal efficiency of 27%, requiring only energy from the sun for its operation and the product water is distilled water, free of salts, of great potential value for human use and consumption in accordance with current official standards.

Construction of Au/ZnWO4/CdS Ternary Photocatalysts with Oxygen Vacancy Modification for Efficient Photocatalytic Hydrogen Production

AbstractRational design and optimization of the photocatalyst architecture, aimed at effectively enhancing light absorption and accelerating charge separation and transfer, can lead to the accomplishment of sustainable photocatalytic hydrogen production. In this study, a ternary system of Au/ZnWO4/CdS is prepared with oxygen vacancy modification through a combination of hydrothermal, chemical precipitation, and photochemical deposition methods. The addition of CdS and Au nanoparticles significantly enhances the light absorption range of ZnWO4 (ZWO) and creates more active sites for hydrogen production. The type‐II engineered heterojunction, in combination with Au as a cocatalyst, is a viable and efficient method for enhancing the separation and transport of electron–hole pairs, thereby facilitating the effective precipitation of hydrogen through photocatalysis. 5A10ZC exhibits a hydrogen production rate of 5483.62 µmol g−1 h−1, which is 167 times higher than that of unmodified ZWO and 29 times higher than that of pure CdS. In addition, it exhibits excellent cycle stability in the hydrogen production cycle stability test. The photoelectrochemical test results show that the construction of the system improves the separation and transfer efficiency of photogenerated carriers. This study provides a new inspiration for the construction of high‐performance photocatalytic materials.

Nanofiber membranes immobilized with in-situ grown nanoparticles for enhanced wetting resistance in direct contact membrane distillation

Immobilizing nanoparticles (NPs) onto the hydrophobic nanofiber membrane surface is an effective method to enhance its resistance to pore wetting in membrane distillation (MD) due to construction of a hierarchical structure. However, loading NPs onto the fabricated membrane through post-treatment techniques (e.g., electrospray, physical vapor deposition etc.) results in agglomeration of NPs and their weak attachment with membrane surface. To address this issue, we utilize precipitation and crystallization methods to achieve in-situ growth of zinc oxide (ZnO) NPs onto nanofiber surface for intensifying their interaction. Morphological characterization demonstrated that the size and amount of in-situ grown ZnO NPs could be controlled by varying reaction time and concentration of precipitation agent. Furthermore, the resultant nanofiber membrane with higher contact angles (163°) showed stable water flux and effective salt rejection in presence of surfactant and oil. Finally, the kinetics of wetting progression monitored by ultrasonic time-domain reflectometry (UTDR) further confirmed that the early partial wetting induced by surfactants was significantly restrained owing to the hierarchical structure generated by the in-situ grown ZnO NPs. This study suggested the modified nanofiber membrane presented outstanding wetting resistance to low-surface-tension foulants and promise for desalination in MD.