Preparation of mixed matrix self-cleaning membrane incorporated by Z-scheme heterostructure via robust engineering in terms of dimension for decreasing cake fouling in a cross-flow reactor.

Reducing irreversible fouling in polymer membranes by integrating photocatalytic and membrane processes as the self-cleaning photocatalytic membrane is a promising candidate for improving membrane filtration performance. In this study, mixed matrix photocatalytic membranes were prepared from the combination of different morphologies ZnO-g-C3N4 heterostructure in the polymer matrix by the phase-separation method. To investigate the self-cleaning and performance properties of mixed matrix photocatalytic membranes prepared from different morphologies heterostructures, the photocatalytic membrane reactor with a visible-light source was applied. Nanoflower/nanosheet (NF/NS) ZnO-g-C3N4 photocatalytic membrane showed good self-cleaning performance owing to the high photocatalytic performance of NF/NS ZnO-g-C3N4 heterostructure by the reduction of irreversible membrane fouling, thus improving the antifouling and filtration performance of the membrane. Also, the morphology and the uniform distribution of the NF/NS ZnO-g-C3N4 heterostructure in the membrane matrix caused good hydrophilic properties, high porosity, and a more symmetrical structure in the (NF/NS) ZnO-g-C3N4 photocatalytic membrane (F4). For the F4 membrane, the permeability and rejection values increased from 40.35 L m-2 h-1 and 90.9% in the dark environment to 84.37 L m-2 h-1 and 97.4% under visible-light for dye pollutants. Accordingly, F4 had the best filtration and self-cleaning performance, which can be used as a promising visible-light photocatalytic membrane in wastewater treatment processes.

Preparation of high-crystalline and non-metal modified g-C3N4 for improving ultrasound-accelerated white-LED-light-driven photocatalytic performances.

As a non-metallic organic semiconductor, graphitic carbon nitride (g-C3N4) has received much attention due to its unique physicochemical properties. However, the photocatalytic activity of this semiconductor faces challenges due to factors such as low electronic conductivity and limited active sites provided on its surface. The morphology and structure of g-C3N4, including macro/micro morphology, crystal structure and electronic structure can affect its catalytic activity. Non-metallic heteroatom doping is considered as an effective method to tune the optical, electronic and other physicochemical properties of g-C3N4. Here, we synthesized non-metal-doped highly crystalline g-C3N4 by one-pot calcination method, which enhanced the photocatalytic activity of g-C3N4 such as mesoporous nature, reduced band gap, wide-range photousability, improved charge carrier recombination, and the electrical conductivity was improved. Hence, the use of low-power white-LED-light illumination (λ ≥ 420 nm) and ultrasound (US) irradiation synergistically engendered the Methylene Blue (MB) mineralization efficiency elevated to 100% within 120 min by following the pseudo-first-order mechanism under the following condition (i.e., pH 11, 0.75 g L-1 of O-doped g-C3N4 and S-doped g-C3N4, 20 mg L-1 MB, 0.25 ml s-1 O2, and spontaneous raising temperature). In addition, the rapid removal of MB by sonophotocatalysis was 4 times higher than that of primary photocatalysis. And radical scavenging experiments showed that the maximum distribution of active species corresponds to superoxide radical [Formula: see text]. More importantly, the sonophotocatalytic degradation ability of O-doped g-C3N4 and S-doped g-C3N4 was remarkably sustained even after the sixth consecutive run.

Integrating graphene oxide into layers of PVDF/PVDF@cross-linked sodium alginate/polyamide membrane for efficiently enhancing desalination performances.

The membrane modules of the water treatment system are faced costly damages; thereby executing pre-desalination units based on Nanofiltration (NF) could prevent these suffers, and improve the permeated water flux (PWF) and salt rejection (SR). Hence, we focused on the construction of a novel ternary-layer NF membrane through "electrospinning Polyvinylidene Fluoride (PVDF) (as bottom layer)", "generating middle layer by electrospinning PVDF along with, the implementation cross-linking after electrospraying Sodium Alginate", and "synthesizing Polyamide (as top layer) through interfacial polymerization". More importantly, it anticipated that the Taguchi statistical method can expeditiously optimize the effects of Graphene Oxide nano-sheets (GOns) on water-dependent properties, such as PWF and SR. Astonishingly, the desalination capabilities significantly improved, when the top, middle, and bottom layers simultaneously had 1, 0.1, and 0.1 wt.% of GOns, respectively. Overall, comparing the performances between the optimized sample containing low-dosage and without GOns demonstrated the PWF ameliorated from 6.68 to 20.36 L/m2 h; also, the SR ability remained on an incremental basis as NaCl < MgCl2 < MgSO4 under 6 bar pressure. Manifestly, these authentic results denoted promising, innovative, and large-scaling insights when effectual PWF and SR be necessary.

Volatile organic compounds (VOCs) removal by photocatalysts: A review.

Amplified anthropogenic release of volatile organic compounds (VOCs) gets worse air quality and human health. Photocatalytic degradation of VOCs is the practical strategy due to its low cost, simplicity, high efficiency, and environmental sustainability. Different types of photocatalyst activated by UV and visible lights are applied for VOC degradation. This review tries to investigate the state-of-art of recently published papers on this subject with a focus on the high-efficiency photocatalyst. The novel photocatalysts are introduced and enhancing photocatalytic activity strategies such as the hybrid of two/three photocatalyst, impurity doping, and heterojunctions with narrow bandgap semiconductors have been explained. The procedures of visible light activation of the photocatalysts are discussed with attention to current problems and future challenges. In addition, effective operational parameters in the photocatalytic degradation of VOCs have been reviewed with their advantages and drawbacks. A series of strategies are developed for the efficient utilization of visible light photocatalysts and improving new materials or design structures to degrade produced toxic intermediates/by-products during photocatalytic degradation of VOCs. This review shows that there are significant challenges in the applications of photocatalysts in the selective removal of VOCs. Several approaches should be combined to produce synergistic effects, which may lead to much higher photocatalytic performance than individual strategies. Another challenge is to develop efficient photocatalysts to meet real problems on an industrial scale.

Design of a new light curable starch-based hydrogel drug delivery system to improve the release rate of quercetin as a poorly water-soluble drug.

In spite of quercetin advantages, its utilization as a cancer drug is confined due to its very low water solubility and bioavailability. Accordingly, we prepared a biodegradable starch-based hydrogel, using a new technique to control and improve quercetin release and bioavailability. For this purpose, the molecular structure of starch was modified by polyethylene glycol/acrylate and Fe3O4 nanoparticles were used to enhance mechanical properties of hydrogel. In order to prepare the final hydrogel drug carrier, the modified starch was directly mixed with quercetin and other additives in different ratios and cured under blue light. Synthesis confirmation and structural properties of the modified starch, silanized and pure Fe3O4 nanoparticles and final hydrogel were studied using 1H NMR, FT-IR, SEM, XRD, TGA, VSM and DLS analyses. We improved in vitro drug release to 56.62%, while the maximum release of quercetin from the starch-based hydrogel in our previous study was only 27% (Doosti et al., 2019).

Improvement of microwave absorption properties of polyester coatings using NiFe2O4, X-doped g-C3N4 (X = S, P, and O), and MTiO3 (M = Fe, Mg, and Zn) nanofillers.

In recent decades, to reduce electromagnetic pollution, scientists focus on finding new microwave absorbers with effective performance, thin thickness, and broad bandwidth. In this work, the nanoparticles of NiFe2O4, X-doped g-C3N4 (M = S, P, and O), and MTiO3 (M = Fe, Mg, and Zn) were successfully synthesized using co-precipitation, specific heat program, and semi-wet sol-gel methods, respectively. The synthesized nanoparticles were utilized as absorption agents and polyester resin as the matrix. Morphology, particle size, crystal structure, and chemical composition of the prepared nanocomposites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), and energy dispersive X-Ray analysis (EDX), respectively. The microwave absorption performance of the coatings was also investigated by a vector network analyzer (VNA). Moreover, the effect of different parameters on the performance of absorbent coatings was studied by the Taguchi method and optimized to achieve an optimal absorbent. The results showed that the optimal nanocomposite has the reflectance loss (RL) less than - 30 dB (equal to absorption > 99%) at a high-frequency range (8-12 GHz) and 1 mm thickness. Furthermore, the addition of such novel nanoparticles to absorbents resulted in high values of attenuation constant (more than 200 dB/m) at the X-band. Therefore, the polyester coating filled with ZnTiO3, O-doped g-C3N4, and NiFe2O4 nanofillers can be considered a high-efficiency and low-density absorber.

Synthesis of a green bigel using cottonseed oil/cannabis oil/alginate/ferula gum for quercetin release: Synergistic effects for treating infertility in rats.

Although therapeutic effect of quercetin (Quer) was reported on non-alcoholic fatty liver disease (NAFLD), destructive effects have been shown on male fertility due to its pro-oxidative properties. On the other hand, NAFLD impairs germ cells to produce sperm and leads to male infertility. Herein, a biocompatible and green bigel was designed for Quer delivery to prevent infertility induced by NAFLD as the increasing complications. Bigels were prepared using cottonseed oil/cannabis oil/alginate/ferula gum and optimized by the mixture design method. NAFLD was induced by 58% of dietary calorie as lard and 42 g/l fructose for 16 weeks in Sprague-Dawley rats. So on animals received 2 mg/kg Quer loaded on bigels, free bigels, or free Quer for 45 days as daily gavage. Semen was analyzed, followed by the assessment of DNA integrity. Count, motility, and normal morphology reached the healthy control group at the bigel-Quer-treated one. Moreover, all of these parameters were significantly higher in the bigel-Quer group than the Quer and bigel, alone. The percent of sperms with head and tail abnormality decreased considerably in the bigel-Quer group compared with the Quer, free bigel, and NAFLD groups. Serum testosterone levels significantly increased and reached the healthy control group in the bigel-Quer group. DNA fragmentation of sperm significantly decreased in the bigel-Quer group (p < 0.05). The bigel showed synergistic effects with Quer for treating infertility in rats with NAFLD.

Enhancing quercetin bioavailability by super paramagnetic starch-based hydrogel grafted with fumaric acid: An in vitro and in vivo study.

Application of Quercetin (Quer) as a natural flavonoid is confined because of limited solubility in water and stability in the body. Herein, we prepared a biodegradable super paramagnetic starch-based hydrogel grafted onto fumaric acid for increasing Quer bioavailability and controlling its release. The molecular structure of starch was modified by using fumaric acid to increase hydrophilicity of hydrogel, and iron oxide nanoparticles is used to strengthen its physical and mechanical properties. The structural, morphological and magnetic properties of the optimized hydrogel were characterized. Application of the synthesized hydrogel was assessed in the in vitro and in vivo studies. In vitro release curve was nicely fitted to the Higuchi model. Stability and bioavailability of Quer were significantly increased at the plasma and liver of rats which received 100 mg kg-1 Quer- loaded on synthetic hydrogel compared with 100 mg kg-1 free Quer (p < 0.05).

Starch-based polyurethane/CuO nanocomposite foam: Antibacterial effects for infection control.

In the present study, a new method for the synthesis of the open cell flexible polyurethane foams (PUFs) was developed by using starch powder and the modification of closed cell foam formulation. Starch is the second largest polymeric carbohydrate as a macromolecule on this planet with a large number of glucose units. Copper oxide nanoparticles (CuO NPs) were synthesized by thermal degradation method at different temperatures of 400, 600 and 800 °C as antimicrobial agents. The antimicrobial activity of CuO NPs and commercial CuO powder against the main causes of hospital infections were tested. CuO600 was the most effective antimicrobial agent and enhanced polymer matrix tensile strength with starch powder as new polyurethane foams (PUFs) cell opener with high tensile strength. The effects of parameters on tensile strength were optimized using response surface methodology (RSM). CuO NPs and PUF had optimal conditions and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Foam synthesized at the optimal conditions had an open cell structure with high tensile strength and efficient antimicrobial activity that made them suitable to be used as an antimicrobial hospital mattress to control hospital infections.

Adsorption of cefixime from aqueous solutions using modified hardened paste of Portland cement by perlite; optimization by Taguchi method.

In the present study, we have used a simple and cost-effective removal technique by a commercially available Fe-Al-SiO2 containing complex material (hardened paste of Portland cement (HPPC)). The adsorbing performance of HPPC and modified HPPC with perlite for removal of cefixime from aqueous solutions was investigated comparatively by using batch adsorption studies. HPPC has been selected because of the main advantages such as high efficiency, simple separation of sludge, low-cost and abundant availability. A Taguchi orthogonal array experimental design with an OA16 (4(5)) matrix was employed to optimize the affecting factors of adsorbate concentration, adsorbent dosage, type of adsorbent, contact time and pH. On the basis of equilibrium adsorption data, Langmuir, Freundlich and Temkin adsorption isotherm models were also confirmed. The results showed that HPPC and modified HPPC were both efficient adsorbents for cefixime removal.