Effect Of Weight Ratio Research Articles

Application of zeolite based nanocomposites for wastewater remediation: Evaluating newer and environmentally benign approaches

The presence of heavy metal ions and emerging pollutants in water poses a great risk to various biological ecosystems as a result of their high toxicity. Consequently, devising efficient and environmentally friendly methods to decontaminate these waters is of high interest to many researchers around the world. Among the varied water treatment and desalination means, adsorption and photocatalysis have been widely employed. However, the discussion and analysis of the use of zeolite-based composites as adsorbents are somehow minimal. The porous aluminosilicates (zeolites) are excellent candidates in wastewater treatment owing to various mechanisms of pollutants removal that they possess. The purpose of this review is thus to provide a synopsis of the current developments in the fabrication and application of nanocomposites based on zeolite as adsorbents and photocatalysts for the extraction of heavy metals, dyes and emerging pollutants from wastewaters. The review goes on to look into the effect of weight ratio on photocatalyst, photodegradation pathways, and various factors that influence photocatalysis and adsorption.

Carbon-Based Nanomaterials Thin Film Deposited on a Flexible Substrate for Strain Sensing Application.

Hybrid nanomaterial film consisting of multi-walled carbon nanotubes (MWCNT) and graphene nanoplatelet (GNP) were deposited on a highly flexible polyimide (PI) substrate using spray gun. The hybridization between 2-D GNP and 1-D MWCNT reduces stacking among the nanomaterials and produces a thin film with a porous structure. Carbon-based nanomaterials of MWCNT and GNP with high electrical conductivity can be employed to detect the deformation and damage for structural health monitoring. The strain sensing capability of carbon-based hybrid nanomaterial film was evaluated by its piezoresistive behavior, which correlates the change of electrical resistance with the applied strain through a tensile test. The effects of weight ratio between MWCNT and GNP and the total amount of hybrid nanomaterials on the strain sensitivity of the nanomaterial thin film were investigated. Experimental results showed that both the electrical conductivity and strain sensitivity of the hybrid nanomaterial film increased with the increase of the GNP contents. The gauge factor used to characterize the strain sensitivity of the nanomaterial film increased from 7.75 to 24 as the GNP weight ratio increased from 0 wt.% to 100 wt.%. In this work, a simple, low cost, and easy to implement deposition process was proposed to prepare a highly flexible nanomaterial film. A high strain sensitivity with gauge factor of 24 was achieved for the nanomaterial thin film.

Core-shell ZIF-8@MIL-68(In) derived ZnO nanoparticles-embedded In2O3 hollow tubular with oxygen vacancy for photocatalytic degradation of antibiotic pollutant

Developing a novel core-multishelled metal oxide hollow tube with rich oxygen vacancy is highly attractive in photocatalytic degradation of antibiotic pollutant. Herein, ZnO@In2O3 core-shell hollow microtubes were synthesized via one-step calcination of ZIF-8@MIL-68(In) formed by an in-situ self-assembly. TEM images demonstrate that 0D ZnO quantum dots (QDs) shell with 0.2 µm were well coated on the surface of 1D In2O3 hollow tube as the core with 1.2 µm. The synthesized heterostructure indicates the enhanced photocatalytic performance in tetracycline (TC) degradation compared with single ZIF-derived ZnO and MIL-68(In)-derived In2O3 under simulated solar irradiation. Besides, organic pollutants including malachite green (MG), methylene blue (MB) and rhodamine B (RhB) are further used to evaluate the photocatalytic activity of ZnO@In2O3, and the effect of weight ratios between ZnO and In2O3 on degradation efficiency is also studies. The ZnO@In2O3 heterojunction can provide higher specific surface area, expose more active sites, possess appropriate number of oxygen vacancies, enhance light absorption and further effectively boost the transfer and separation of photoinduced charge carriers. In addition, the proposed photocatalytic mechanism and degradation pathway are discussed in detail based on active species trapping test, electron spin resonance (ESR) and LCMS.

Self-Assembly of Self-Cleaning Polystyrene/Styrene-Butadiene-Styrene Films with Well-Ordered Micro-Structures

Well-ordered porous films have been widely applied in various areas, such as chemical sensors, microreactors, and tissue engineering. In this article, we propose a novel air-liquid interface self-assembly method to fabricate well-ordered porous polystyrene (PS)/styrene–butadiene–styrene (SBS) films by simply dipping the PS/SBS chloroform solutions onto the surface of a mixed water/ethanol liquid phase. The proper volume ratio of water/ethanol is necessary for the formation of films with highly uniform pore size. The effect of weight ratio of PS/SBS, the volume ratio of water/ethanol and the concentration of the solutions were experimentally investigated. The pore size decreases with the concentration of polymer solution, and the structure becomes more regular with the decrease of water/ethanol volume ratio. Ordered structure can be formed under PS/SBS in a certain weight ratio. The self-assembled films also have the function of self-cleaning. Besides the analysis of structural characteristic, the self-assembly mechanism was also discussed.

Investigation on Physical and Mechanical Properties of Banana and Palmyra Fiber Reinforced Epoxy Composites

Abstract The present work addresses the physical and mechanical properties of banana and palmyra fiber reinforced epoxy composites with the aim of study on the effect of weight ratio and fiber percentage. The banana and palmyra fibers were arranged with different weight ratios (1:1, 1:3, and 3:1) and then mixed with the epoxy matrix by hand lay-up technique to prepare the hybrid composites with various fiber percentages (10%, 20%, 30% and 40%). The properties are measured by testing its density, water absorption, tensile strength, impact strength, hardness and flexural strength and compared. From the results, it was indicated that addition of banana and palmyra fiber in to the matrix material up to 30% by fiber percentage results in increasing the mechanical properties and slightly variation with weight ratios. Interfacial analysis of the hybrid composites were also observed by using scanning electron microscope (SEM) to study the internal failures and micro structure of the tested specimen.

Solvent-free nanoalumina loaded nanocellulose aerogel for efficient oil and organic solvent adsorption

HypothesisCellulose-based aerogel, due to its rich reserves, environmental friendliness and porous structure, is considered as a new type of adsorbents for treating oil and water pollution. However, the functionalization of cellulose aerogel is still required for the efficient increase of its adsorption performance in wide applications. The combination of nanomaterials could significantly improve the adsorption capability of nanocellulose aerogel. ExperimentsIn this work, nanocomposite aerogels comprising of nanocellulose and nanoalumina (NC/Al2O3) are produced via a solvent-free method and the effect of weight ratios between nanocellulose and nanoalumina on the adsorption properties of NC/Al2O3 aerogels has been studied. FindingsThe results reveal that the NC/Al2O3 aerogel with a low density of 5.1 mg cm−3 could obtain the optimal pore microstructures and the highest oil and organic solvent adsorption capacities with the preparation condition under the nanocellulose/nanoalumina weight ratio of 1:0.25 and 0.4 wt% of nanocellulose in aqueous solution. The presence of nanoalumina facilitates the change of microstructure morphologies, the increase of BET specific surface area and the adsorption capacities of NC aerogel. Compared with pure NC aerogel (74.07 ± 1.67, 69.87 ± 1.01, 81.21 ± 3.20, 52.07 ± 1.70, 48.49 ± 1.01, 75.45 ± 3.58 and 87.03 ± 0.46 g g−1 for thiophene, anhydrous ethanol, ethyl acetate, cyclohexane, sesame oil, acetone and dichloromethane, respectively), the NC/Al2O3 aerogel manifests an outstanding adsorption capacity (108.07 ± 0.37, 89.91 ± 4.83, 93.93 ± 3.81, 71.13 ± 2.48, 64.83 ± 2.25, 85.19 ± 3.87 and 117.65 ± 5.68 g g−1, accordingly). By considering the desirable performance features and the convenient fabrication approach, this nanocellulose nanocomposite aerogel might be a feasible alternative for oily waste water recovery and conservation of environment.

Fabrication of chitosan/polyvinylpyrrolidone hydrogel scaffolds containing PLGA microparticles loaded with dexamethasone for biomedical applications

One of the most effective approaches for treatment of chronic rhinosinusitis is the use of hydrogel scaffolds with the sustained release of a given required drug. With this in mind, first, we synthesized and characterized poly (lactide-co-glycolide) (PLGA) micro and nano particles loaded with dexamethasone (DEX). We observed a 7-day release of DEX from nanoparticles, while the microparticles showed a 22-day release profile. Due to their slower rate of release, the PLGA microparticles loaded with DEX (PLGADEX microparticles) were specifically chosen for this study. As a second step, chitosan/polyvinylpyrrolidone (PVP) based hydrogels were prepared in various weight ratios and the PLGADEX microparticles were optimized in their structure based on variable gelation times. The morphological studies showed PLGADEX microparticles homogenously dispersed in the hydrogels. Moreover, the effect of weight ratio in the presence and absence of optimum percentage of PLGADEX microparticles was studied. The resultant hydrogels demonstrated a range of advantages, including good mechanical strength, porous morphology, amorphous structure, high swelling ratio, controlled biodegradability rate, and antibacterial activity. Additionally, a cytotoxicity analysis confirmed that the hydrogel scaffolds do not have adverse effects on the cells; our release studies in the hydrogel with the highest PVP content also showed 80% release after 30 days. Based on these results we were able to predict and control some of the mechanical properties, including the microstructure of the scaffolds, as well as the drug release, by optimizing the polymers - microparticle concentration, plus their resulting interactions. This optimized hydrogel can become part of a suitable alternative for treatment of allergic rhinitis and chronic sinusitis.

Physical and thermal behaviour of areca and coconut shell powder reinforced epoxy composites

An understanding of the temperature dependent properties such as thermal conductivity, specific heat, and thermal diffusivity of natural fiber reinforced polymer composites are an important to determining their heat conduction/insulation capability. In the present study, epoxy based hybrid composites were fabricated by reinforcing the areca and coconut shell powder (CSP) to improve the thermal insulation. The two reinforcements were added together with different weight ratios as 1:1, 1:3, and 3:1 and the total fiber loading of 10–40 wt%. The effect of weight ratio and fiber loading on the density, water absorption, thermal conductivity, specific heat, and thermal diffusivity properties of areca-CSP reinforced epoxy composites was examined. The results revealed that the density, thermal conductivity, and specific heat of hybrid composites were decreased with increase in fiber loading. On other hand, it was observed that the water absorption of hybrid composite was increases with the fiber loading.

Further investigation of poly(glycidyl methacrylate-co-styrene) as a curing agent for soy-based wood adhesives

ABSTRACT In this study, poly(glycidyl methacrylate-co-styrene) (PGS) was investigated as a curing agent for soybean flour (SF)-based wood adhesives in the presence of polyethyleneimine (PEI). The seven-ply plywood panels made with the SF-PGS-PEI adhesives passed a three-cycle soak test that is the industrial standard test for evaluation of the water resistance of decorative plywood panels in the USA. SF, PGS, and PEI were found to be all essential components for the adhesives. The mixing of SF and PGS first, followed by addition of PEI, was found to be the only mixing order that was able to result in superior properties of the adhesives. The viscosity of SF-PGS-PEI adhesives remained relatively low for at least 60 min of the storage, which made the adhesives easy to use. Effects of weight ratios among SF, PGS, and PEI in the adhesives, the molar ratio between glycidyl methacrylate and styrene in the PGS, and hot-press conditions of making the plywood panels on the water resistance of the resulting plywood panels were extensively investigated. The adhesion mechanisms are discussed in detail.

Direct Z-scheme 2D/2D MnIn2S4/g-C3N4 architectures with highly efficient photocatalytic activities towards treatment of pharmaceutical wastewater and hydrogen evolution

Semiconductor photocatalysis has been regarded as an environmentally friendly technology in wastewater treatment and energy production. Here, a series of direct Z-scheme MnIn2S4/g-C3N4 (MnISCN) photocatalysts without electron mediators were fabricated by a simple hydrothermal route on the basis of in-situ loading of MnIn2S4 (MnIS) nanoflakes on the surface of g-C3N4 (CN) nanosheets. Photocatalytic performances evaluated under visible light irradiation revealed these Z-scheme heterostructured photocatalysts exhibited higher photocatalytic activities than single-component samples. The effect of weight ratio between MnIn2S4 nanoflakes and mesoporous CN nanosheets on photocatalytic activity towards treatment of pharmaceutical wastewater was optimized to achieve highly efficient photocatalytic activities for both degradation of pharmaceutical wastewater and hydrogen generation compared with alone MnIS nanoflakes and isolated mesoporous CN nanosheets. The significant enhancement in photocatalytic activity could be primarily ascribed to the construction of Z-scheme MnISCN architectures, which effectively accelerated the transfer and separation of photogenerated charge carriers via tight interface contacts built among these two components. The recycling experiments for pharmaceutical wastewater treatment revealed the excellent stability of MnISCN nanocomposites. The advantages of highly efficient photocatalytic activity and excellent stability endowed a promising potential for MnISCN nanocomposites to apply in photocatalytic fields.

A preparation method for the treatment of Cr(VI) composite adsorbent Ca-AC

The effects of weight ratio of Eucalyptus and CaCl2, carbonization temperature and carbonization time on the composite adsorbent (Ca-AC) were studied. The best conditions for composite adsorbent (Ca-AC) were obtained: the weight ratio of CaCl2 to the eucalyptus sawdust was 2:1; the carbonization temperature was 650 °C; the carbonization time was 80 min. The Ca-AC yield reached 28.88%; the Cr(VI) adsorption value was 131.03 mg±g-1. The morphology and structure of the adsorbents were characterized. The results showed that the specific surface area of Ca-AC can reach 713 m2±g-1. The carboxyl, hydroxyl, lactones groups and amino could be determined on the activated carbon surface.

Relationship between structure and properties in high‐performance PA6/SEBS‐g‐MA/(PPO/PS) blends: The role of PPO and PS

ABSTRACTThis work aimed at studying the role of poly(phenylene oxide) (PPO) and polystyrene (PS) in toughening polyamide‐6 (PA6)/styrene‐ethylene‐butadiene‐styrene block copolymer grafted with maleic anhydride (SEBS‐g‐MA) blends. The effects of weight ratio and content of PPO/PS on the morphology and mechanical behaviors of PA6/SEBS‐g‐MA/(PPO/PS) blends were studied by scanning electron microscope and mechanical tests. Driving by the interfacial tension and the spreading coefficient, the “core–shell” particles formed by PPO/PS (core) and SEBS‐g‐MA (shell) played the key role in toughening the PA6 blends. As PS improved the distribution of the “core–shell” particles due to its low viscosity, and PPO guaranteed the entanglement density of the PPO/PS phase, the 3/1 weight ratio of PPO/PS supplied the blends optimal mechanical properties. Within certain range, the increased content of PPO/PS could supply more efficient toughening particles and bring better mechanical properties. Thus, by adjusting the weight ratio and content of PPO and PS, the PA6/SEBS‐g‐MA/(PPO/PS) blends with excellent impact strength, high tensile strength, and good heat deflection temperature were obtained. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45281.

MAPLE prepared heterostructures with oligoazomethine: Fullerene derivative mixed layer for photovoltaic applications

Mixed layers of azomethine oligomers containing 2,5-diamino-3,4-dicyanothiophene as central unit and triphenylamine (LV5) or carbazol (LV4) at both ends as donor and fullerene derivative, [6,6]-phenyl-C61 butyric acid butyl ester ([C60]PCB-C4) as acceptor, have been prepared by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on glass/ITO and Si substrates. The effect of weight ratio between donor and acceptor (1:1; 1:2) and solvent type (chloroform, dimethylsulphoxide) on the optical (UV–vis transmission/absorption, photoluminescence) and morphological properties of LV4 (LV5): [C60]PCB-C4 mixed layers has been evidenced. Dark and under illumination I–V characteristics of the heterostructures realized with these mixed layers sandwiched between ITO and Al electrodes have revealed a solar cell behavior for the heterostructures prepared with both LV4 and LV5 using chloroform as matrix solvent. The solar cell structure realized with oligomer LV5, glass/ITO/LV5: [C60]PCB-C4 (1:1) has shown the best parameters.

Incorporation of Rutin in Electrospun Pullulan/PVA Nanofibers for Novel UV-Resistant Properties.

This study aimed to investigate the incorporation of rutin into electrospun pullulan and poly(vinyl alcohol) (PVA) nanofibers to obtain ultraviolet (UV)-resistant properties. The effect of weight ratios between pullulan and PVA, and the addition of rutin on the nanofibers’ morphology and diameters were studied and characterized by scanning electron microscopy (SEM). Fourier transform infrared (FTIR) analysis was utilized to investigate the interaction between pullulan and PVA, as well as with rutin. The results showed that the inclusion of PVA results in the increase in the fiber’s diameter. The addition of rutin had no obvious effect on the fibers’ average diameters when the content of rutin was less than 7.41%. FTIR results indicated that a hydrogen bond formed between pullulan and PVA, also between these polymers and rutin. Moreover, the addition of rutin could enhance the mechanical properties due to its stiff structure and could decrease the transmittance of UVA and UVB to be fewer than 5%; meanwhile, the value of ultraviolet protection factor (UPF) reached more than 40 and 50 when the content of rutin was 4.46% and 5.67%, respectively. Therefore, the electrospun pullulan/PVA/rutin nanofibrous mats showed excellent UV resistance and have potential applications in anti-ultraviolet packaging and dressing materials.

Design and evaluation of a novel chitosan-based system for colon-specific drug delivery

Tritrichomonas foetus is a flagellated protozoan parasite that colonizes the feline colon causing colitis and chronic foul smelling diarrhoea. Despite the efficacy of Ronidazole in the treatment of T. foetus, Ronidazole has been reported to cause neurotoxicity in some cats due to rapid absorption in the small intestine. A novel amphoteric derivative of chitosan was synthesised and characterized. A combination of time, pH, and an enzyme controlled system was used in a study of a new compression coated tablet for delivery of Ronidazole to the colon. Axial, radial swelling and erosion of selected tablets were carried out in various media. The effect of weight ratio, enzyme and pH on in vitro drug release profile was investigated. The results show that less than 2% of the drug was released in the physiological environment of the stomach and small intestine.

Reduction-Roast Leaching of Low-Grade Pyrolusite Using Bagasse as a Reducing Agent

Bagasse, a fibrous residue from sugarcane juice extraction, was used as a reducing agent to roast low-grade pyrolusite in N2. The roasted ore was further leached using sulfuric acid, to convert manganese oxide in the ore to manganese sulfate. The effects of weight ratio of bagasse to manganese ore, roasting temperature, roasting time, leaching temperature, leaching time, stirring speed and sulfuric acid concentration on the leaching recovery of manganese were investigated. Optimal conditions were determined to be a bagasse to manganese ore weight ratio of 0.8:10, roasting temperature of 500°C for 40 min, leaching stirring speed of 100 rpm, sulfuric acid concentration of 3 mol•L-1 and leaching temperature of 50°C for 40 min. The leaching recovery rate of manganese was up to 97.8% at the optimal conditions.

The Chemical Modification of Waste PET and its Application for a Wood-Polymer Composite Binder

The application of hydroxyl terminated polyethylene terephthalate (PET-OH) as a starting pre-polymer to react with polymeric methylene di-isocyanate (p-MDI) for synthesis of polyurethane as a wood-composite binder was studied. The PET-OH was modified from waste polyethylene terephthalate (PET) bottles by glycolysis reaction. The effect of weight ratios of binder and rubber-wood sawdust particles and the mole ratios of hydroxyl (OH) of PET-OH and isocyanate (NCO) of p-MDI on mechanical properties were investigated. The properties of wood-polymer composites from PET-OH were also compared with the polyurethane composites from polyethylene glycol (PEG) as a commercial polyol. It was found that mechanical properties of wood-polymer composites increased with the increase of binders and polyol contents and then decreased and PET-OH showed the greater properties than PEG. The ratio of wood particle and the binder of 60:40 by weight and the ratio of OH and NCO of 0.01:1 by mole gave the best mechanical properties.

The supercapacitive performances of Co(OH)2/Ni(OH)2 composites in lithium hydroxide solution: Selection of electrolyte and effect of weight ratio

The supercapacitive performances of Co(OH)2/Ni(OH)2 composites in lithium hydroxide solution are investigated in detail. Cyclic voltammetries and galvanostatic charge/discharge measurements reveal that LiOH is the most suitable electrolyte for the composite electrodes among MOH (M=Li, Na and K). The redox behavior of the Co(OH)2/Ni(OH)2 composites different to that of the pure components shows that weight ratio of Co(OH)2/Ni(OH)2 exerts a great influence on the capacitive performances. After 1000 continuous charge/discharge cycles, the capacitance retention ratio for the composite electrode with the weight ratio of 2/3 is elevated from 41.6% to 88.2% compared with pure Ni(OH)2 electrode, exhibiting improved long-life cyclability.

Novel Blend Films Prepared from Solution of Collagen and Cellulose in 1-Allyl-3-methylimidazolium Chloride Ionic Liquid

Collagen/cellulose films were made by the blend solutions of collagen, cellulose in this paper. To begin with, collagen and cellulose was dissolved in 1-allyl-3-methylimidazolium chloride ([Amim]Cl）. The structure of the blend films was characterized by FTIR and XRD. The effects of weight ratio between the two polymers on light transmittance, tensile strength, elongation at break and water absorption of the film were studied. The results showed that there were strong interactions and good compatibility between collagen and cellulose in the film and the polymers have strongest interactions at the mixing ratio of 5:5. The blend films possess better properties such as mechanical and water absorption properties than those made of single polymer.

Crosslinked poly(acrylonitrile–glycidyl methacrylate) as a novel gel polymer electrolyte

Novel gel polymer electrolytes (GPEs) based on poly(acrylonitrile–glycidyl methacrylate) (P(AN–GMA)) crosslinked with α,ω-diamino poly(propylene oxide) (Jeffamine) of various weight ratios and molecular weights have been prepared, and the crosslinked polymers were characterized by FT-IR and thermal analysis. It is revealed that the crosslinked polymers were amorphous in pristine state and became crystallized when doped with lithium electrolyte. Their swelling properties and mechanical behaviors were investigated and found to be heavily affected by the weight ratio and molecular weight of Jeffamine. The effect of weight ratios and molecular weights of Jeffamine on the ionic conductivity of the GPEs based on the crosslinked polymers were determined by AC impedance spectroscopy. GPEs consisting of Jeffamine of higher molecular weights and increased weight ratios showed higher ionic conductivity. The GPE based on P(AN–GMA) crosslinked with Jeffamine D2000 at a weight ratio of 1.5 exhibited the highest ionic conductivity of 8.23 × 10 −4 S cm −1 at 25 °C, and preserved a moderate mechanical strength. The crosslinked polymers can be potential candidates for the construction of rechargeable lithium batteries.