Solvent Research Articles

Green and chemical synthesis of TiO2 nanoparticles: An In-depth comparative analysis and photoluminescence study

Titania nanoparticles were synthesized by sol-gel method using chemical and natural solvents. Isopropanol is used as a chemical solvent for the reduction of ions. Further, Jasminum and Magnolia champaca flower extracts were individually used as natural solvents which acts as both reducing and stabilizing agents. The role of natural solvents over chemical solvents on the structure, phase, morphology, and optical properties of TiO2 nanoparticles were investigated. Synthesis using natural solvents led to rutile phase of TiO2 nanoparticles while, chemical synthesis produced anatase phase. Green synthesis yielded larger crystallite size TiO2 compared to chemical synthesis. Synthesized TiO2 exhibited PL emission centered at 397 nm with excitation 325 nm associated with weak emissions noticed at 450 nm, 470 nm, and 520 nm.

Green superhydrophobic surface engineering of PET fabric for advanced water-solvent separation

This paper presents the preparation of the PET membrane for effective organic solvent separation achieved through an advanced superhydrophobic surface engineering of PET fabric utilizing biomimicry and a green chemistry approach. The superhydrophobicity of the PET surface was reached through a hierarchical nanocomposite coating that involved the integration of biomimetic polydopamine (PDA) coating, green-synthesized zinc oxide (ZnO) nanoparticles (NPs), and non-fluorinated quaternary ammonium cation silane (Si-QAC) coverage. The morphology and surface chemical composition of the resultant Si-QAC/ZnO/PDA@PET membrane were characterized by SEM, EDS, FT-IR, XRD, and AFM analysis. The surface topography and water contact angle were also correlated with surface roughness and its superhydrophobicity. The resulting Si-QAC/ZnO/PDA@PET membrane exhibited promising superhydrophobic properties, characterized by a water contact angle ranging from 150° to 160° and a roll-off angle between 5° and 2° as well as stability against severe conditions, including acidic and alkaline exposure, mechanical abrasion, and UV radiations. Moreover, the Si-QAC/ZnO/PDA@PET membrane exhibited bacterial repulsive properties against E. coli and Staphylococcus sp. The separation efficiency of various aliphatic and aromatic organic solvents (n-hexane, toluene, chloroform, and petroleum ether) from water higher than 90 % was also observed, making the membrane a potential candidate for different industrial applications, particularly for the separation of organic solvents from water.

Facile fabrication of sulfonated bacterial cellulose-silane composite aerogels via in suit polymerization for enhanced oil/water separation performance.

Cellulose-based aerogels have emerged as highly promising materials for oil-water separation because of their highly porous nature, low bulk density, cost-effectiveness, and functional performance. In this study, a novel, robust, and hydrophobic bacterial cellulose aerogel (HBCA) was reported for highly efficient oil/water separation, which was formed by incorporating methyltrimethoxysilane (MTMS) into sulfonated nano-fibrillated bacterial cellulose (SNBC) matrix through freeze-drying method. The structural integrity of the SNBC/MTMS aerogel was ensured by its three-dimensional linked network structure. The resultant aerogel demonstrated superior hydrophobicity with a contact angle of 152.4°. As an oil-absorbing material, it selectively adsorbed different types of oils and organic solvents, with a saturation adsorption capacity ranging from 42.14 to 85.37 g·g-1. Additionally, this composite aerogel demonstrated outstanding separation efficiency (98.48 %) in continuous oil-water mixture processes, suggesting promising potential applications in the treatment of industrial oil pollution and oil spill accidents. This study indicates that the proposed HBCA with sulfonated nano-fibrillated bacterial cellulose is a potential and effective material for addressing environmental challenges related to oil contamination.

Particle size control and performance analysis of the ammonium perchlorate-based molecular perovskite energetic material

To solve the problem of high mechanical sensitivity and difficulty in coating caused by large crystal particles of ammonium perchlorate-based molecular perovskite energetic material (H2dabco)[NH4(ClO4)3] (DAP-4), we conducted research on the particle size regulation and performance of it. Firstly, we determined the solubility of DAP-4 in six commonly used organic solvents using a static method. And based on this data, an UDAP-4 (D50 = 6.19 μm) was successfully prepared. The characterization results of UDAP-4 revealed that UDAP-4 exhibits a decrease in thermal decomposition peak temperature (Tp) by 19 °C compared to the raw material, along with an 87.92kJ/mol reduction in activation energy (Ea). The studies on different particle sizes indicate that UDAP-4 maintains good thermal stability while significantly enhancing safety performance. UDAP-4 shows an over 20J increase in impact sensitivity, and a 12N increase in minimum frictional load. And the smaller the particle size, the lower the sensitivity. These findings provide a reference for further secure applications of DAP-4 in an academic context.

Colistin-niclosamide effervescent dry suspension combats colistin-resistant Salmonella in vitro and in vivo

The increasing incidence of bacterial infections caused by multidrug-resistant (MDR) Gram-negative bacteria has deepened the need for new effective treatments. It has been reported that niclosamide (NIC) can restore the sensitivity of Gram-negative bacteria to colistin (COL). However, NIC is practically insoluble in water and sparingly soluble in organic solvents, leading to limited therapeutic applications. This study aims to prepare a COL-NIC effervescent dry suspension (CNEDS) and evaluate its antibacterial effect against COL-resistant Salmonella both in vitro and in broiler chickens. With the sedimentation volume ratio as an index, suitable suspending agent, wetting agent, filler and effervescent agent were screened through a single-factor method. The preparation conditions were optimized using the Box-Behnken response surface method to obtain the formulation for CNEDS. The quality evaluation results showed that the successfully prepared CNEDS had a sedimentation volume ratio of 0.99, a drying weight loss of 1.3%, and a re-dispersion capability of 1-2 times, all of which met pharmacopoeial requirements. In terms of pharmacological evaluation, we first demonstrated that CNEDS substantially restored COL sensitivity against COL-resistant bacteria. Subsequently, time-killing analysis, scanning electron microscopy (SEM) and live/dead assays confirmed the antibacterial activity of CNEDS against COL-resistant bacteria. Finally, a Salmonella infection model in broiler chickens was established to further assess the therapeutic effect of CNEDS in vivo. CNEDS improved the survival rate of broiler chickens, reduced the bacterial burden on organs. These findings suggest that CNEDS effectively overcome COL resistance, indicating its potential for the treatment of COL-resistant bacterial infections in broiler chickens.

Preparation and Optimization of Gemcitabine Loaded PLGA Nanoparticle Using Box-Behnken Design for Targeting to Brain: In Vitro Characterization, Cytotoxicity and Apoptosis Study

Background: Treatment of glioma with conventional approaches remains a far-reaching target to provide the desired outcome. This study aimed to develop and optimize Gemcitabine hydrochloride- loaded PLGA nanoparticles (GNPs) using the Box-Behnken design methodology. The independent variables chosen for this study included the quantity of Polymer (PLGA) (X1), Tween 80 (X2), and Sonication time (X3), whereas the dependent variables were Particle size (Y1) EE % (Y2) and PDI (Y3). The optimized biodegradable nanoparticles were investigated for their anticancer effectiveness in U87MG human glioblastoma cells in vitro. Method: The formulation process involved two steps. Initially, emulsification was carried out by combining the organic polymer solution with the aqueous surfactant solution. Subsequently, in the second step, the organic solvent was evaporated, resulting in the precipitation of the polymer and the formation of nanoparticles. The quantity of PLGA, Tween 80, and PVA (at a constant concentration) was adjusted based on the experimental trial approach. Subsequently, the PLGA-based nanoparticles underwent characterization, wherein their particle size, encapsulation efficiency, polydispersity index (PDI), and cumulative release were assessed. The optimal formulation composition was determined as 200 mg of PLGA, 4 ml of Tween 80, and 2 mg of PVA. Further, the optimized GNPs were evaluated for their anti-cancer effectiveness on U87 MG cells by MTT and apoptosis assay. Results: The results demonstrated that the optimized GNPs exhibited an encapsulation efficiency of 81.66 %, a particle size of 140.1 nm, and a PDI of 0.37. The morphology of the Opt-GNPs was observed to be spherical through transmission electron microscopy (TEM). Conclusion: The Apoptosis study further confirmed the observations of MTT assay as the Opt- GNPs significantly enhanced the apoptosis in U-87 MG cells than the Standard marketed formulation.

Carbon-Chalcogenide Cross-Coupling Reactions in Water

: Over the past two decades, researchers have witnessed the synthesis of diaryl sulfides and diaryl selenides via transition metals-mediated carbon-heteroatom cross-coupling reactions in the presence of various organic and inorganic solvents. The use of water as a clean and environmentally friendly solvent in cross-coupling chemistry of C-S/Se bond formations has attracted profound interest owing to its availability, non-toxicity, low cost and renewability. The most commonly used solvents have been recognized as being of environmental concern, but the use of green and eco-friendly solvents like water is frequently considered with respect to the recovery of catalysts, isolation of products, and recycling. The fundamental interactions between the water and the transition metal catalysts or ligands are viewed from mechanistic aspects, which mostly favours the rational selection of high-performance and safe solvents. In this article, the authors intended to focus extensively on the critical role of water in various transition metals mediated C-S/Se cross-coupling methodologies.

A computational probe into the physicochemical properties of cyclodextrin-based deep eutectic solvents for extraction processes

The use of deep eutectic solvents (DESs) as environmentally friendly alternatives to traditional volatile organic solvents has attracted significant attention in the industrial sector. In this study, molecular dynamics simulations were utilized to examine the physicochemical and structural characteristics of novel DESs—specifically DES1, DES2, and DES3—comprising methyl-β-cyclodextrin (MBCD) mixed with formic acid (FA), propionic acid (PA), and acetic acid (AA), respectively, in a 1:3 molar ratio. Structural analysis, as revealed by the combined distribution function and radial distribution function, indicated that the dominant interactions within the DESs occur between the hydroxyl hydrogen of the acids and the hydroxyl oxygen of MBCD, as well as between the hydroxyl hydrogen of MBCD and the carbonyl oxygen of the acids. Furthermore, it was observed that MBCD forms more hydrogen bonds and non-bonded interactions with PA than with FA or AA. As a result, PA exhibits a lower self-diffusion coefficient compared to FA and AA. The findings also demonstrate that the influence of the acid type on the density and isothermal compressibility of the DESs follows the order: DES2 > DES1 > DES3 for density and DES3 > DES2 > DES1 for compressibility. Overall, this study provides valuable insights into the behavior of novel MBCD-based DESs, offering predictive insights for their potential applications in extraction processes.

Solvent-free green synthesis of anion exchange membranes via photo-polymerization for efficient desalination by electrodialysis

A green anion exchange membrane for electrodialysis desalination was synthesized using a solvent-free photo-polymerization approach. Vinylbenzyl chloride (monomer), tripropylene glycol diacrylate (crosslinker), and photoinitiator were mixed and subjected to UV polymerization for 20 min to create the base membrane, followed by positive charge modification with 1-methylimidazole. This method avoids organic solvents, offering economic and environmental benefits. By adjusting the degrees of crosslinking and positive charge, precise control over the membrane's microstructure and properties was achieved. The optimized membrane showed an area resistance of 1.67 Ω cm2 and a transport number of 0.956, demonstrating exceptional electrochemical performance. Under comparable conditions, the optimized membrane improved the NaCl removal rate by 11.47 %, increased current efficiency by 10.61 %, and reduced energy consumption by 16.75 % compared to commercial AMV membrane, highlighting its potential for scalable seawater desalination through electrodialysis.

Experiment-based Abraham model solute descriptors for 2‑[4-(dibutylamino)-2-hydroxybenzoyl]benzoic acid

ABSTRACT Abraham model solute descriptors for 2‑[4-(dibutylamino)-2-hydroxybenzoyl]benzoic acid were determined from the compound’s published solubility data in 10 organic solvents of varying polarity and hydrogen-bonding character. The calculated hydrogen-bond donor descriptor value, A = 0.548, suggests that intramolecular bond formation occurs between the hydrogen atom on the -OH functional group and one of the two lone pairs of electrons on the oxygen atom of the ketone functional group, >C=O, which would result in the formation of a six-membered hydrogen-bonded ring structure. A much larger A-solute descriptor would be expected if the hydrogen atoms of both the -OH and -COOH functional groups were free to engage in intermolecular H-bond formation with surrounding solvent molecules.

Ammonia and temperature sensing applications using fluorometric and colorimetric microparticles and polymeric films doped with BODIPY-emitters.

Fourfunctionalized BODIPY derivatives(BDP1 to BDP4) were synthesizedand their optical properties investigatedboth in solution and when incorporated into a solid matrix. Recognizing the versatility of BODIPY derivatives and the increasing interest in developing new luminescent organic dyes embedded in polymers, the BODIPY derivatives were dispersed into two types of polymeric matrices: Poly(methyl methacrylate) (PMMA) and Thermoplastic Polyurethane (TPU), both as films and microparticles. This resulted in eight new BODIPY-doped polymer films and eight types of BODIPY-doped polymeric microparticles for use in aqueous solutions. The integration of the BODIPY dyes into the polymeric matrices combines the unique properties of the polymer films, such as porosity, flexibility, and elasticity, with the excellent photophysical characteristics of the BODIPYs. Importantly, the dispersion minimized issues such as aggregation-caused quenching commonly observed in solid-state luminescent materials. The thermometric responses of all polymer films were evaluated by studying their solid-state emission spectra in the 25-200°C temperature range. The reversibility of these temperature-induced changes was also assessed, revealing excellent recovery of luminescence. These promising results suggest these materials could have applications as fluorescent thermometric sensors. Furthermore, we explored the potential of the brominated (BDP3) and chalcogenated (BDP4) BODIPY derivatives as ammonia sensors. The two derivatives produced yellow fluorescent products upon interaction with the analyte. Kinetic studies using solid-state emission spectra of BDP4@TPU and BDP4@PMMA showed significant differences in reaction rates (minutes for BDP4@TPU and hours in the case of BDP4@PMMA) attributable to the higher permeability of TPU when compared with PMMA. Detection and quantification of ammonia concentration were conducted by means of simple photographic analysis, measuring the "R" (red) and "G" (green) components of RGB color parameters. Theresults from the photographic method correlated well with the results from fluorimetric spectroscopy studies. The photographic analysis is straightforward, portable, and does not require expensive equipment. Finally, we successfully applied polymeric microparticles doped with BODIPYs to detect ammonia in water, demonstrating their effectiveness without the need for organic solvents. This highlights their potential for environmental monitoring and other applications requiring sensitive and selective detection methods.

Immobilized Horseradish Peroxidase on Enriched Diazo-Activated Silica Gel Harnessed High Biocatalytic Performance at a Steady State in Organic Solvent.

Dimethyldichlorosilane (DMDCS), an efficient silane coupling reagent appearing between the -OH groups of silica gel (SG) and picric acid, instantaneously produces a derivative enriched with nitro groups. The nitro group acting as an end-cap terminates the reaction and subsequently was converted into diazo to couple tyrosine's phenol ring via its O-carbon, the inert center to immobilize horseradish peroxidase (HRP) in a multipoint mode. It maintains the status quo of the native enzyme's protein folding and the entire protein groups' chemistry. The molecular formula of the synthesized material was verified and appeared as {Si(OSi)4 (H2O)x}n{-O-Si(CH3)2-O-C6H2(N+≡N)3(HRP)}4·yH2O; the parameters were evaluated as x = 0.5, n = 1158, and y = 752. The immobilized biocatalyst's activity in organic solvents was 1.5 times better than that in an aqueous medium; it worked smoothly, wherein the activity in both solvents stabilized at six months and continued up to nine months at 63 ± 3% compared to the initial.

Bio-inspired one-pot synthesis of luminescent silver nanoparticles and its significant utility as a fluorescence nano sensor for analysis of two adjunctive COVID-19 drugs.

This study reveals one-step green synthesis of plant inspired silver nanoparticles (Ag-NPs). The synthesis procedure relies on the bio-reduction of Ag+ to Ag0 using orange waste (orange peel) extract as cheap, readily available, sustainable, biocompatible feedstocks as a reducing and stabilizing agent. The prepared Ag-NPs passed through a full characterization procedure for better confirmation and elucidation of optical and structural properties. The fluorescence of the prepared Ag-NPs has a quantum yield of 17.15% enabling its potential use in chemical sensing of drugs. Ag-NPs are conceived to be used as a fluorescent nano sensor for sensitive, ecofriendly, rapid spectrofluorimetric determination of two recent direct oral anticoagulants, namely, rivaroxaban (RIV) and edoxaban tosylate monohydrate (EDT); COVID-19 adjunctive drugs in their raw materials and pharmaceutical tablets. The fluorescence of the prepared Ag-NPs at 333nm was found to be substantially quenched in existence of increasing concentrations of each drug. The quenching mechanisms were studied and explained. The validation of the method revealed linear correlation over the ranges of 0.5-10µg/ml with an excellent regression correlation (r=0.9999) for both drugs with minimum detection limits of 0.14 and 0.16µg/ml for rivaroxaban and edoxaban tosylate monohydrate, correspondingly. Three different metrics were employed for verifying the greenness profile of the presented study. The findings of the greenness assessment were congruent and compatible with the green synthesis procedure, ecofriendly analysis, and the exclusion of using organic solvents and noxious materials opening an avenue for green synthesis of nanoparticles instead of chemical and physical methods.

Nile Red Fluorescence: Where's the Twist?

Nile Red is a fluorescent dye used extensively in bioimaging due to its strong solvatochromism. The photophysics underpinning Nile Red's fluorescence has been disputed for decades, with some studies claiming that the dye fluoresces from two excited states and/or that the main emissive state is twisted and intramolecular charge-transfer (ICT) in character as opposed to planar ICT (PICT). To resolve these long-standing questions, a combined experimental and theoretical study was used to unravel the mechanism of Nile Red's fluorescence. Time-resolved fluorescence measurements indicated that Nile Red emission occurs from a single excited state. Theoretical calculations revealed no evidence for a low-lying TICT state, with the S1 minimum corresponding to a PICT state. Ultrafast pump-probe spectroscopic data contained no signatures associated with an additional excited state involved in the fluorescence decay of Nile Red. Collectively, these data in polar and nonpolar solvents refute dual fluorescence in Nile Red and definitively demonstrate that emission occurs from a PICT state.

Aqueous Dispersion Polymerization for the Development of Lamivudine-Polyacrylonitrile Nanoparticles through Quality by Design Approach.

The development of polymeric nanoparticles (NPs) from preformed polymers usually requires the use of organic solvents and is more expensive. Hence, in this work, the development of polymeric nanoparticles by in situ aqueous dispersion polymerization from the monomers was set as an objective. Acrylonitrile monomer based polymeric NPs comprising Lamivudine (LMV) as a model drug were prepared using the aqueous dispersion polymerization technique. A quality by design approach was applied to optimise various formulation and process factors viz. monomer concentration, initiator concentration, stabilizer concentration and polymerization temperature. Polymerization time (PT), entrapment efficiency (EE), particle size (PS), and drug release rate constant (k) were taken as the responses to define the quality of the prepared NPs. Design of experiments analysis followed by optimization was performed to identify the optimized combination of the factors. Later, the optimized formulation was studied for the physical state of the LMV in the nanoparticles, surface morphology of the NPs and cytotoxicity studies. The optimized formulation was found to have 91.7 min. of PT, 81.4% of EE, 253 nm of PS and a k value of 0.262 h-1 (18 h to release 99%). The cytotoxicity studies indicated that the NPs were highly safe to use. These results altogether inferred that LMV contained NPs were developed effectively from the acrylonitrile monomer by the aqueous dispersion polymerization method.

A Brief Review of Radiolabelling Nucleic Acid-Based Molecules for Tracking and Monitoring.

The rise of nucleic acid-based therapeutics continues apace. At the same time, the need for radiolabelled oligonucleotides for determination of spatial distribution is increasing. Complex molecular structures with mostly multiple charges and low solubility in organic solvents increase the challenge of integrating radionuclides. In preclinical research, it is important to understand the fate of new drug candidates in biodistribution studies, target binding or biotransformation studies. Depending on a specific question, the selection of a respective radiolabelling strategy is crucial. Radiometals for molecular imaging with positron emission tomography or single-photon computed tomography generally require an attached chelating agent for stable complexation of the metal with the oligonucleotide, whereas labelling using carbon-11/-14 or tritium allows incorporation of the radioisotope into the native structure without altering it. Moreover, the suitability of direct radiolabelling of the oligonucleotide of interest or indirect radiolabelling, for example, by a two-step pretargeting approach, for the study design requires consideration. This review focuses on the challenges of radiolabelling nucleic acid-based molecules with beta-plus, gamma and beta-minus emitters and their use for tracking and monitoring.

Isolation and identification of antifungal, antibacterial and nematocide agents from marine bacillus gottheilii MSB1.

Pathogenic fungi employ numerous strategies to colonize plants, infect them, reduce crop yield and quality, and cause significant losses in agricultural production. The increasing use of chemical pesticides has led to various ecological and environmental issues, including the emergence of resistant weeds, soil compaction, and water pollution, all negatively impacting agricultural sustainability. Additionally, the extensive development of synthetic fungicides has adverse effects on animal and human health, prompting the exploration of alternative approaches and green strategies for phytopathogen control. Microorganisms living in sponges represent a promising source of novel bioactive secondary metabolites, potentially useful in developing new nematicidal and antimicrobial agents. This study focuses on extracting bioactive compounds from endosymbiotic bacteria associated with the marine sponge Hyrtios erect sp. (collected from NIOF Station, Hurghada, Red Sea, Egypt) using various organic solvents. Bacillus sp. was isolated and identified through 16S rRNA gene sequencing. The biocidal activity of Bacillus gotheilii MSB1 extracts was screened against plant pathogenic bacteria, fungi, and nematodes. The n-butanol extract showed significant potential as a biological fungicide against Alternaria alternata and Fusarium oxysporum. Both n-hexane and ethyl acetate extracts exhibited negative impacts against the plant pathogenic bacteria Erwinia carotovora and Ralstonia solanacearum, whereas the n-butanol extract had a positive effect. Regarding nematicidal activity, ethyl acetate and n-butanol extracts demonstrated in-vitro activity against the root-knot nematode Meloidogyne incognita, which causes serious vegetable crop diseases, but the n-hexane extract showed no positive effects. The findings suggest that bioactive compounds from endosymbiotic bacteria associated with marine sponges, particularly B. gotheilii MSB1, hold significant potential as alternative biological control agents against plant pathogens. The n-butanol extract, in particular, displayed promising biocidal activities against various plant pathogenic fungi, bacteria, and nematodes. These results support further exploration and development of such bioactive compounds as sustainable, environmentally friendly alternatives to synthetic pesticides and fungicides in agricultural practices.

Donor–Acceptor Type Solvatochromic Flavonoid Materials Fluorphores for Polarity Sensing and Real‐Time Temperature Monitoring

AbstractElectron donor–acceptor (D–A) molecules are emerging tools for designing sensitive luminogens, attracting significant research attention. However, due to poor quantum yields under certain conditions, current D–A fluorophores often suffer from fluorescence quenching in practical applications. Developing new D–A dyes and functional composites is crucial for expanding their applications. Here, a novel donor–acceptor type flavonoid dye molecule, namely “AFL”, exhibiting both polarity‐dependent fluorescence emission wavelength shift and viscosity‐dependent intensity change, for polarity measurement and temperature sensing is designed and synthesized. Because the intramolecular charge transfer (ICT) can be enhanced by a decrease of excited state energy caused in high‐polarity organic solvents, AFL undergoes fluorescence emission wavelength shift that shows fluorescence color response to solvents of different polarities and hence differentiates between them. Moreover, the actual temperature can be monitored by the as‐designed AFL@tetradecanoic acid (AFL@TA) sensor. By combining with TA, viscosity sensitively changes upon the temperature change of insoluble composites, thus realizing the fluorescence intensity response to temperature. Remarkable recyclable performance and satisfactory mechanical properties are integrated. This study provides a promising approach to developing a new D–A fluorescent probe and furnishes perspectives on the potential of such D–A type flavonoid material in stimuli‐responsive systems with a focus on visualization sensing technology.

Molecular dynamics simulation of extraction of Curcuma longa L. extract using subcritical water.

Humans have utilized plants for various purposes, including sustenance and medical treatment for millennia. Researchers have extensively investigated medicinal plants' potential in drug development, spurred by their rich array of chemical compounds. Curcumin, a valuable bioactive compound, is extracted from Turmeric, known by the scientific name Curcuma Longa L. Notably, curcumin boasts potent antioxidant and anti-inflammatory properties, making it a promising candidate for treating cancer and other microbial diseases. Therefore, the simulation study of the extraction of this important medicinal compound by water, which is a green solvent, was carried out. This study employed molecular dynamics simulation for the first time to explore the extraction of Curcuma Longa L. extract using subcritical water. The simulations were carried out at constant pressure and different temperatures, using the Compass force field in the Lammps simulation package. The findings revealed an increase in the amount of Curcuma longa extract with rising temperature, indicating a weakening of hydrogen bonds in water molecules. Water lost its polar state with increasing temperature and became a suitable non-polar solvent for extracting non-polar compounds. The average absolute relative deviation (AARD) for calculated and simulated density data was 6.45%.

Interfacially Cross-Linked Polydopamine/Polybenzimidazole Composite Membranes for Organic Solvent Nanofiltration.

Interfacial cross-linking was used to prepare composite organic solvent nanofiltration (OSN) membranes comprising a polydopamine (PDA) active layer formed on a polybenzimidazole (PBI) substrate. Dibromo-p-xylene (DBX) was employed as a cross-linking agent to make the composite membranes chemically stable against harsh polar aprotic solvents. The interfacial cross-linking of PDA/PBI allowed for finely tuning the molecular weight cutoff (MWCO) of the membrane, resulting in a membrane with precise molecular separation capabilities for OSN. The morphology and surface properties of the membranes were characterized, and a membrane with a MWCO of 286 Da was investigated for OSN of a series of solvents. The membrane permeance was in the order of acetonitrile (MeCN) > methanol (MeOH) > acetone > toluene > dimethylformamide (DMF) > heptane > ethanol (EtOH) > isopropanol (IPA) > tetrahydrofuran (THF). The membranes displayed a sharp pore size distribution, yielding a rejection rate of over 99% for Rose Bengal (RB, MW 1020 g/mol) and Remazol brilliant blue (RBB, MW 626.5 g/mol) from DMF and EtOH solutions. When it came to methyl orange (MO, MW 327.3 g/mol) that had a molecular weight closer to the MWCO of the membrane, the membrane still displayed a high rejection rate of 95% and 99% in nanofiltrating solvents DMF and EtOH, respectively. In addition, it was demonstrated that the membrane was able to effectively fractionate mixed solutes having molecular weights appropriate for the MWCO rating of the membrane during OSN.