Effect Of Solvent Ratio Research Articles

Effect of solvent ratio on omega-3 extraction of catfish (Clarias sp.) and pangasius catfish (Pangasius sp.) using low-temperature crystallization method

Effect of solvent ratio on omega-3 extraction of catfish (Clarias sp.) and pangasius catfish (Pangasius sp.) using low-temperature crystallization method

Effect of Solvent Ratio (Ethylene Glycol/Water) in the Synthesis of Pt/C Cathode Catalysts on PEM Fuel Cell Performance

Abstract The ethylene glycol (EG)/water mixture composition of an alkaline one-step polyol synthesis for Pt/C catalysts was systematically investigated and optimized for a low ethylene glycol content with regards to resulting Pt particle size and electrochemical performance of membrane electrode assemblies tested as proton exchange membrane (PEM) fuel cell cathode catalysts. Beginning test fuel cell data show a possible reduction of the required EG amount per gram of synthesized catalyst by up to 98% without significantly compromising the initial electrochemical performance. Taking catalyst durability into account, a Pt/C catalyst synthesized with 40 vol% H2O and 32 mM Pt precursor concentration showed a decent initial electrochemical performance (716 mV at 1 A cm-2) as well as an accelerated stress test-derived stability similar to an internal reference catalyst, obtained with 100 vol% EG. In summary, our study shows that optimizing the amount of water and platinum precursor in the synthesis process can lead to catalysts with excellent performance for PEM fuel cells while contributing significantly to cost reduction by using less EG during synthesis.

Ultrathin 2D-MOFs for dual-enzyme cascade biocatalysis with sensitive glucose detection performances.

In recent years, two-dimensional nanosheet metal-organic frameworks (2D MOFs) have been widely considered as promising carriers for enzyme immobilization owing to their large surface area, designable and tunable structures, and other properties that enhance enzyme loading and modulate interactions with enzymes. In this study, a series of ultrathin 2D M-TCPP (M = Co, Ni, Zn, Cu) nanosheets were synthesized employing a surfactant-assisted bottom-up approach, and the effect of solvent ratio on the morphology and properties of 2D MOFs was explored. After systematic characterization, Cu-based 2D MOFs with large specific surface areas and excellent water stability was selected as the carrier for the co-immobilization of glucose oxidase (GOx) and horseradish peroxidase (HRP). The effects of adsorption and covalent immobilization strategies on bis-enzyme loading and enzyme activity, as well as their applications in rapid glucose detection, were systematically investigated. The results showed that A-CTGH and C-CTGH owned enzyme loadings of 187.9 and 249.1mg/g, respectively, and exhibited superior enzymatic activity when exposed to harsh environments compared to free enzymes. In addition, the covalently immobilized biocatalyst based on GOx demonstrated a more sensitive glucose detection performance, including a wide linear range from 5.0 to 16μM with a detection limit of 0.6μM.

Effect of solvent ratio, temperature and time on extraction of bioactive compounds and their antioxidant potential from callus, leaf and peel extracts of Citrus pseudolimon Taraka

Effect of solvent ratio, temperature and time on extraction of bioactive compounds and their antioxidant potential from callus, leaf and peel extracts of Citrus pseudolimon Taraka

Preparation and performance study of sedum multiceps-like biomimetic structure TKX-50 with various particle sizes

Biomimetic structures often endow materials with excellent performance. In order to explore the impact of biomimetic structures on the performance of energetic materials, the sedum multiceps-like bionic structure dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) was constructed by self-assembly technology, and controllable particle size adjustment was achieved. Moreover, the effects of solvent ratio, solute content, stirring flow field, and temperature on the quality of sedum multiceps-like TKX-50 crystals were explored, and the formation mechanism of sedum multiceps-like TKX-50 crystals was analyzed. Then, the crystal morphology, crystal form and particle size distribution of sedum multiceps-like TKX-50 were characterized, furthermore, the thermal properties and mechanical sensitivity of sedum multiceps-like TKX-50 were emphatically studied. The results showed that the sedum multiceps-like biomimetic structure TKX-50 was assembled from needle shaped or sheet shaped small particle crystals, and the sedum multiceps-like structure did not change the explosive crystal form of TKX-50. What's more, the thermal decomposition activation energy of the prepared sedum multiceps-like TKX-50 crystal was at least 157.30 kJ⋅mol−1 and at most 185.27 kJ⋅mol−1, and the thermal energy was greatly affected by particle size. In addition, the minimum and maximum ultimate impact energy of the sedum multiceps-like TKX-50 crystals are 20 J and 55 J. The ultimate impact energy of the sedum multiceps-like TKX-50 crystal with different particle sizes is higher than that of the raw TKX-50 (15 J). As a consequence, the sedum multiceps-like bionic structure effectively improves the energy release of TKX-50, reduces the impact sensitivity, and improves the uniformity of particle size distribution.

RDX crystals with high sphericity prepared by resonance acoustic mixing assisted solvent etching technology

In order to obtain high-quality spherical RDX crystal particles, the RDX crystals were suspended in a mixed solvent of cyclohexanone and cyclohexane, subsequently a solvent etching study was carried out under the action of vibration/acoustic flow coupled flow field, which generated by resonance acoustic mixing. The effects of solvent ratio, temperature, acceleration and experiment time on morphology as well as particle size of RDX crystals were studied. Not only were the morphology, particle size distribution and crystal form of RDX crystals determined, but also the thermal decomposition performance and mechanical sensitivity of spherical RDX were examined and discussed. Results indicated that under the process of solvent/non-solvent volume ratio at 1:2, temperature of 40°C, acceleration of 40 g and experiment time of 4 h, α-type RDX crystal with sphericity of 0.92 can be obtained. Furthermore, the median particle size (D50) of spherical RDX crystals is 215.8 μm with a unimodal particle size distribution (size span 1.34). For one thing, the thermal decomposition peak temperature of spherical RDX is about 2.5°C higher than that of raw RDX, and apparent activation energy reaches 444.68 kJ/mol. For another thing, impact sensitivity and friction sensitivity of spherical RDX are 18.18% and 33.33% lower than that of raw RDX, respectively. It demonstrates that safety of spherical RDX under thermal, impact and friction stimuli has been improved.

Comparison of Maseration and Sonication Method on Flavonoid Extraction from Mango Leaves: Effect of Solvent Ratio

Mango leaf extract has proven to contain flavonoids that serve as antioxidants. In this study, a comparison between traditional maceration and sonication on flavonoid extraction from mango leaf was investigated. The various ratios of ethanol and acetone were utilized as solvents (1:5, 1:10, and 1:15). The sonication process, which uses an ultrasonic cleaning bath set at 40 oC, takes 30 minutes as contrasted to the maceration procedure of 36 hours treatment at room temperature. The flavonoid test using aluminum (III) chloride (AlCl3) colorimetric technique shows that acetone provides greater solvent power than ethanol. According to this study, the optimal ratios for the maceration and sonication procedures are 1:10 and 1:15, respectively. The maceration process resulted in the optimum extract of 0.186 mgQE/g dry leaves. Meanwhile, using a 1:15 acetone solvent ratio and the sonication method, the highest concentration of flavonoid components was discovered, reaching 0.143 mgQE/g dry material with 54 times shorter time.

The Effect of Solvent Ratio and Extraction Time on Antioxidant Activity and Flavonoid Concentration of Kedawung Leaf (Parkia Biglobosa) Through Microwave-Assisted Extraction

Kedawung (Parkia biglobosa) contains various ingredients such as alkaloids, saponins, tannins, flavonoids, and terpenoids. The flavonoid content in Kedawung is thought to have an antioxidant effect. Antioxidants are able to counteract free radicals that enter the body by donating electrons and binding them. Currently, the microwave-assisted extraction (MAE) method is widely used because the solute mass transfer from the sample matrix into the solvent is higher than the Soxhlet method. The following study aimed to know the effect of solvent ratio and extraction time on the extraction yield, flavonoid concentration, and antioxidant activity of kedawung leaf through microwave-assisted extraction. In this method, we used 40% ethanol to make the varied solute: solvent ratio such as 1:20, 1:30, 1:40, and 1:50. The extraction time used in this method was 4-7 minutes respectively. Microwave-assisted extraction has good performance to extract the active substance in Kedawung leaves. The highest yield 16.36%, total flavonoid content (57.32±2,2 mg QE/g extract), and DPPH scavenging activity (88.87±1.062%) was obtained in the extraction with a solids-solvent ratio of 1:40 g/mL, at an extraction time of 6 minutes. This method promises to take the active substance in a short time.

One-Step Synthesis of CoFe2O4 Nanomaterials by Solvothermal Method

Abstract Nano-magnetic CoFe2O4 materials with excellent crystallization and high saturation magnetization were synthesized by solvothermal method using Fe(NO3)3·9H2O and Co(NO3)2·6H2O as raw materials and ethanol solution as solvent, respectively. The effects of solvent ratio, reaction temperature and reaction time on the composition and properties of these nanomaterials were explored. The phase, morphology and magnetism of the CoFe2O4 were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The specific surface area of CoFe2O4 was measured by N2 adsorption-desorption isotherm and calculated by the Brunauer-Emmett-Teller (BET) method. The results showed that the structure and magnetic properties of the prepared materials were greatly dependent on the synthesis conditions. Under optimal prepared conditions, i.e., reaction temperature of 200 °C, reaction time of 20 h and pure ethanol (EtOH) solvent, favorable CoFe2O4 material with high purity, small particle size, larger specific surface area and outstanding saturation magnetization was obtained. Importantly, this method with the advantages of easy-operation, environment-friendliness, and without the introduction of any precipitant or surfactant exhibits promise for the industry-scale production of nano-magnetic CoFe2O4 material.

Optimisation of Cell Wall Lipids Extraction from Oil Palm using Mixture of Chloroform and Methanol via Response Surface Methodology

Understanding oil palm’s cell wall lipid during pathogenic invasion, especially from Ganoderma fungus helps us to devise better strategies in managing Basal Stem Rot caused by the fungus effectively. However, as the lipids of plant’s cell wall is a delicate subject, while acquiring them in ample amount with decent quality for research purpose is an excruciating work, therefore it is crucial to develops an optimised method for acquisition. In this study, the effects of solvent ratio, extraction time, extraction temperature and biomass to solvent ratio pertaining effective lipids extraction from oil palm roots cell wall were investigated, aided with Central Composite design (CCD) of Response Surface Methodology (RSM) analysis to obtain optimum oil palm cell wall lipid extraction conditions. Using the projection of RSM model and validation of empirical evaluation, the results revealed that the optimum cell wall lipids yield was obtained under the following extraction conditions: 10 mL of solvent mixture (chloroform: methanol (2:1, v/v)) per gram tissue for 120 min with gentle agitation at 30˚C of extraction temperature. Ultimately, Fourier Transform Spectroscopy (FTIR) analysis was carried out to validate the successful and complete extraction were achieved using the optimised condition.

Effect of Solvents Ratio and Polymer Concentration on Electrospun Polybenzimidazole Nanofiber Membranes Fabrication

Polybenzimidazole (PBI) nanofiber membranes were prepared using electrospinning potential of 15 kV and 0.2 ml/h flow rate at different PBI concentrations (6.5 and 7.5 w/v%) with the solvent mixture ratio (DMAc:DMF) of 1:1 and 2:1, respectively. This study investigated the properties of the polymeric solution and the effects of solvent ratio and concentration on morphology, hydrophobicity and mechanical properties of PBI nanofiber membranes. The solvent mixture ratio and spinning solution properties are not significantly different than the effect of polymer concentration on the viscosity. The viscosity and surface tension of spinning solutions increases with an increase in the concentration of PBI. It was observed that the average diameter of nanofibers was 75 and 97 nm for 6.5 and 7.5 w/v% PBI spinning solution, respectively. Moreover, the contact angle values range from 111 to 125°. This observation reflects that the nanofiber membranes are hydrophobic. Another finding is that the nanofiber membranes with 7.5 w/v% of PBI showed excellent mechanical properties with the maximum stress value of 4.20 ± 0.29 MPa. The finding also shows that the polymer concentration on the spinning solution influences the structure and morphology of the nanofibers. On the other hand, the solvent mixture ratio does not have any significant impact on the nanofiber membranes properties.

The Effect of Solvent Ratio and Precipitation Time on Isolation of Inulin from White Sweet Potato (Ipomoea batatas L.)

White sweet potato has the potential as a source of inulin and is largely abundant in Indonesia. The solvent ratio and precipitation time in ethanol solvent can increase yield produced in the inulin isolation process. This research aimed to determine the effect of different solvent ratios and precipitation times on inulin yield in the extraction-isolation process and as well to know the physical and chemical characteristics of white sweet potato inulin. The stages of the study consisted of determining the total sugar content and sugar reduction, extraction, isolation, physical and chemical characterization. This research used Factorial Completely Randomized Design (RALF) with two factors, different solvent ratio were 1:1, 1:2, and 1:3 with precipitation time for 6, 12, and 18 hours. Data were analyzed used General Linier. The analysis was followed by DMRT (a = 0,05). The results showed that the ratio of 1:2 and the precipitation time of 12 hours produced the best inulin yield of 7.72%. It had an effect on the physical characteristics of inulin that were produced, namely color, solubility, water absorption and water content. While the other characteristics in the form of ash content were not significantly different in ratio and precipitation time.

Effects of Solvent Ratio on the Morphology, Growth, and Photoluminescence of Hexagonal Pyramidal β‐NaYF4:Eu3+ Microrods

Hexagonal pyramidal β‐NaYF4:Eu3+ are synthesized with a facile solvothermal method using the mixture of ethylene glycol and deionized water (DIW) as the reaction solvents. The solvent ratio has a strong effect on the morphology, growth, and photoluminescence (PL) properties of β‐NaYF4:Eu3+. Both the particle size and the aspect ratio of length/diameter of the β‐NaYF4:Eu3+ increase with the proportion of DIW in the reaction solvents, and their crystallinity is also enhanced. The growth behavior of the β‐NaYF4:Eu3+ has been analyzed and explained based on the intrinsic crystal structures, the surface free energy, and the interactions between the reacting ions. The PL of the β‐NaYF4:Eu3+ greatly increases with the proportion of DIW in the reaction solvents, and this is attributed to their enhanced crystallinity with lower density of nonradiative defects. Herein, a useful basis for preparation of luminescent materials with adjustable morphology and strong PL is provided.

Physico-chemical studies of the complexes of Hippuric acid with Cu(II), Ni(II), Zn(II), and Pb(II) ions in ethanol-water mixed solvent system

Potentiometric titrations have been used to calculate the dissociation constants of Hippuric acid and its stability constants with Cu(II), Ni(II), Zn(II), and Pb(II) ions in ethanol-water mixed solvent system at different temperatures, and constant ionic strength of 0.1M solution sodium nitrate. The order of the stability constants of metal complexes at 298 K with respect to ligand was found to be Cu(II) > Pb(II) > Zn(II) > Ni(II). Effect of temperature on stability of hippuric acid complexes with Cu(II) and Pb(II) has been studied in order to calculate the Gibb`s free energy and enthalpy of the complex formation reaction, the results showed that coordination process is spontanous and exothermic. Effect of solvent ratio has been studied only for Cu(II) complex and the dissociation of hippuric acid at given added different ratios decreases on the following order 75% > 50%.

Effects of solvent ratio on the encapsulation of carbon nanotubes/Arthrospira platensis composite within electrospun poly(methyl methacrylate) nanofiber

In recent times, oil spills have plagued oceanic bodies across the globe and has caused catastrophic consequences to the marine ecosystem. As such, this study focuses on developing an oil sorption material capable of removing oil efficiently from water. Electrospinning technique was employed to create biomimetic nanofibers containing carbon nanotube/Arthrospira platensis with PMMA as a base polymer. The composite is vital to fabricate the biomimetic nanofibers as it produces well-defined nanofibers and gives the nanofibers unique configurations for oil sorption. The properties of electrospun nanofibers were examined using FT-IR spectroscopy and X-ray diffractometer. Besides that, the properties of nanofibers were examined through thorough FESEM analysis. Better barrier and morphological properties were obtained for composite nanofibers than for pure polymer nanofibers.

Effect of solvent composition of electrospun PLGA fibers on paclitaxel release

ABSTRACTSite-directed delivery of antimicrobial agents for inflammatory diseases showed significant medical advances, which can be realized through drug-loaded electrospun fibers. In this study, paclitaxel was applied as model hydrophobic drug, and the effect of solvent ratio on drug distribution and release kinetics would be discussed. It was found that different co-solvent ratios (9:1, 7:3, and 5:5, v:v) of chloroform and dimethylformamide could alter the resultant fiber diameter and morphology as well as paclitaxel release kinetics. Slower release was observed with higher ratio of chloroform. XPS results showed that this is primarily due to a better dispersion of paclitaxel in the fibers prepared from solvent ratio of 9:1 whereas the drug was found to accumulate on the surface for samples 5:5 and 7:3. Our results provided insight into the importance of solvent and solvent ratio not just in fabrication of required fibrous structure but also on release of active compounds.

Luminescence of (La,Dy)F3: Effect of solvent ratio (water/ethylene glycol) and Ce3+ co-doping

Luminescent LaF3:Dy3+ and LaF3:Dy3+ co-doped with Ce3+ have been successfully synthesized separately via co-precipitation method. Different ratios of ethylene glycol(EG)/water have been used for the synthesis of LaF3:Dy3+ whereas LaF3:Dy3+ co-doped with Ce3+ have been prepared only in ethylene glycol(EG) medium. The synthesized products have been characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra‐red (FT-IR) and photoluminescence spectroscopy. XRD results show all the samples prepared to be well crystallized in a pure hexagonal structure with no impurity phases. Photoluminescence, lifetime decay and energy transfer efficiency studies indicate the existence of an energy transfer between the Ce3+ and Dy3+ ions, which increases with increase of Dy3+ ions concentration. LaF3:Dy3+ nanophosphor prepared in EG:water mixture(1:1) showed the highest luminescence intensity when compared with those prepared in EG or water alone. This enhancement in luminescence (when using EG-water mixture) might be related to the increase in crystallinity/particle size as well as to the decrease in agglomeration of particles in the corresponding solvent mixture medium.

Fabrication of Functionalized MOFs Incorporated Mixed Matrix Hollow Fiber Membrane for Gas Separation

The metal-organic framework (MOFs) of MIL-53 was functionalized by aminosilane grafting and then incorporated into Ultem®1000 polymer matrix to fabricate mixed matrix hollow fiber membrane (MMHFM) with high separation performance. SEM, XRD, and TGA were performed to characterize the functionalized MIL-53 and prepared MMHFM. The filler particles were embedded in membrane successfully and dispersed well in the polymer matrix. The incorporation of MOFs endowed MMHFM better thermal stability. Moreover, effects of solvent ratio in spinning dope, spinning condition, and testing temperature on gas separation performance of MMHFM were investigated. By optimizing dope composition, air gap distance, and bore fluid composition, MMHFM containing functionalized MIL-53 achieved excellent gas permeance and CO2/N2selectivity. The CO2permeance increased from 12.2 GPU for pure Ultem HFM to 30.9 GPU and the ideal CO2/N2selectivity was enhanced from 25.4 to 34.7 simultaneously. Additionally, gas permeance increased but the selectivity decreased with the temperature increase, which followed the solution-diffusion based transport mechanism.

Effect of solvent ratio and counter ions on the morphology of copper nanoparticles and their catalytic application in β-enaminone synthesis

This work reports the synthesis of shape selective copper nanoparticles (NPs) using a microwave irradiation method, using diverse ratios of an ethylene glycol (EG)/water system and their catalytic application in β-enaminones synthesis.

Ca(OH)2nano-pods: investigation on the effect of solvent ratio on morphology and CO2adsorption capacity

A schematic diagram of the proposed mechanism of the formation of Ca(OH)2pod shapes by a precipitation route.