Alcohol Mixtures Research Articles

Controlled organic solvent transport in ultramicroporous carbon membranes

The drive to decarbonize chemical processes necessitates exploring low-energy solutions for separating complex liquid mixtures ubiquitous in food, pharmaceuticals, petrochemical, and synthetic fuel production industries. This report comprehensively investigates conceptualizing and implementing two novel organic solvent separation processes: Organic Solvent Forward Osmosis (OSFO) and Organic Solvent Pressure Assisted Osmosis (OSPAO). The intrinsic molecular specificity of ultramicroporous carbon molecular sieve (CMS) membranes allowed the unprecedented separation of a complex mixture of short-chain alcohols (e.g., methyl alcohol, ethyl alcohol, and isopropyl alcohol) at room temperature. A new hybridized membrane-based separation methodology, OSPAO, that combines the elements of organic solvent nanofiltration (OSN) and OSFO is introduced. CMS-based OSPAO demonstrated a marked enhancement in the flux of organic species permeate, considerably improving separation efficiencies. The separation modalities presented in this report underscore the essential role of osmosis in the differentiation of organic solvents, thereby contributing valuable insights to osmosis-based separation technologies.

Thermo physical and spectroscopic properties of binary liquid mixtures at various temperatures and correlation with the Jouyban–Acree model (propargyl alcohol, ethanoic acid, propanoic acid and butanoic acid)

ABSTRACT A thorough investigation into binary mixtures of propargyl alcohol and various carboxylic acids (ethanoic, propanoic and butanoic) was conducted. Measurements of density (ρ), speed of sound (u) and viscosity (η) were meticulously performed across the entire range of mole fractions at temperatures (303.15 K−313.15 K) and atmospheric pressure (0.1 MPa). These data were used to calculate key thermodynamic and transport properties, including excess molar volume, excess isentropic compressibility, deviation in viscosity and excess Gibbs free energy of activation for viscous flow. The partial molar properties and infinite dilution molar partial properties were also determined for each binary system. Trends and behaviours were interpreted within the framework of intermolecular interactions, focusing on complex formation and specific chemical forces. The PFP theory and Jouyban–Acree model were critically applied, with confidence in the findings supported by FTIR studies.

Production and performance evaluation of chitosan/collagen/honey nanofibrous membranes for wound dressing applications

Persistent bacterial infections are the leading risk factor that complicates the healing of chronic wounds. In this work, we formulate mixtures of polyvinyl alcohol (P), chitosan (CH), collagen (C), and honey (H) to produce nanofibrous membranes with healing properties. The honey effect at concentrations of 0 % (PCH and PCHC), 5 % (PCHC-5H), 10 % (PCHC-10H), and 15 % (PCHC-15H) on the physicochemical, antibacterial, and biological properties of the developed nanofibers was investigated. Morphological analysis by SEM demonstrated that PCH and PCHC nanofibers had a uniform and homogeneous distribution on their surfaces. However, the increase in honey content increased the fiber diameter (118.11–420.10) and drastically reduced the porosity of the membranes (15.79–92.62 nm). The addition of honey reduces the water vapor transmission rate (WVTR) and the adsorption properties of the membranes. Mechanical tests revealed that nanofibers were more flexible and elastic when honey was added, specifically the PCHC-15H nanofibers with the lowest modulus of elasticity (15 MPa) and the highest elongation at break (220 %). Also, honey significantly improved the antibacterial efficiency of the nanofibers, mainly PCHC-15H nanofibers, which presented the best bacterial reduction rates against Staphylococcus aureus (59.84 %), Pseudomonas aeruginosa (47.27 %), Escherichia coli (65.07 %), and Listeria monocytogenes (49.58 %). In vitro tests with cell cultures suggest that nanofibers were not cytotoxic and exhibited excellent biocompatibility with human fibroblasts (HFb) and keratinocytes (HaCaT), since all treatments showed higher or similar cell viability as opposed to the cell control. Based on the findings, PVA-chitosan-collagen-honey nanofibrous membranes have promise as an antibacterial dressing substitute.

Transcending Lifshitz Theory: Reliable Prediction of Adhesion Forces between Hydrocarbon Surfaces in Condensed Phases Using Molecular Contact Thermodynamics.

Lifshitz theory is widely used to calculate interfacial interaction energies and underpins established approaches to the interpretation of measurement data from experimental methods including the surface forces apparatus and the atomic force microscope. However, a significant limitation of Lifshitz theory is that it uses the bulk dielectric properties of the medium to predict the work of adhesion. Here, we demonstrate that a different approach, in which the interactions between molecules at surfaces and in the medium are described by a set of surface site interaction points (SSIPs), yields interaction free energies that are correlated better with experimentally determined values. The work of adhesion W(Lifshitz) between hydrocarbon surfaces was calculated in 260 liquids using Lifshitz theory and compared with interaction free energies ΔΔG calculated using the SSIP model. The predictions of these models diverge in significant ways. In particular, ΔΔG values for hydrocarbon surfaces are typically small and vary little, but in contrast, W(Lifshitz) values span 4 orders of magnitude. Moreover, the SSIP model yields significantly different ΔΔG values in some liquids for which Lifshitz theory predicts similar values of W(Lifshitz). These divergent predictions were tested using atomic force microscopy. Experimentally determined works of adhesion were closer to the values predicted using the SSIP model than Lifshitz theory. In mixtures of methanol and benzyl alcohol, even greater differences were found in the interaction energies calculated using the two models: the value of ΔΔG calculated using the SSIP model declines smoothly as the benzyl alcohol concentration increases, and values are well correlated with experimental data; however, W(Lifshitz) decreases to a minimum and then increases, reaching a larger value for benzyl alcohol than for methanol. We conclude that the SSIP model provides more reliable estimates of the work of adhesion than Lifshitz theory.

Equilibrium solubility and mathematical modelling of glibenclamide in cosolvent mixtures of glycols and alcohols

ABSTRACT Glibenclamide (GBN) is a commonly used oral medication for treating type-II diabetes that acts by reducing high blood sugar levels. The effectiveness of GBN depends on the quality of the product. The quality is influenced by the solubility properties of a drug. This study aimed to measure the solubility of GBN in various solvent mixtures including some glycols and alcohols. The solubility was determined using a shake-flask method at 298.2 K under atmospheric pressure. The results showed that GBN had the highest solubility in ethylene glycol monomethyl ether and alcohol mixtures compared to the other tested glycols.

Tank-Mix Adjuvants Enhance Pesticide Efficacy by Improving Physicochemical Properties and Spraying Characteristics for Application to Cotton with Unmanned Aerial Vehicles.

Tank-mix adjuvants have been used to reduce spray drift and facilitate the efficacy of pesticides applied with unmanned aerial vehicles (UAVs). However, the effects of specific adjuvants on pesticide characteristics and the mechanism of action remain unclear. Herein, we analyzed the effects of three different types of tank-mix adjuvants (plant oil; mineral oil; and mixture of alcohol and ester) on the surface tension (ST), contact angle, wetting, permeation, evaporation, spray performance, and aphid-control effects of two types of pesticides. The mineral oil adjuvant Weichi (WCH) was highly effective in reducing the pesticide solution ST, improving the wetting and penetration ability, increasing droplet size, and promoting droplet deposition. The mixed alcohol and ester adjuvant Quanrun (QR) showed excellent wetting and antievaporation properties and promoted droplet deposition. A plant oil adjuvant (Beidatong) moderately improved wetting and penetration ability and reduced droplet drift. Field tests showed that the control efficiencies (CEs) of two pesticides were increased after the addition of adjuvants, even with 20% reductions in pesticide application. When the UAV was operated at 1.5 m, the CEs of two pesticides were increased from 65.39 and 66.63% to 73.11-76.52% and 77.91-88.31%, respectively. When operated at 2.5 m, the CEs were increased from 51.24 and 68.60% to 65.06-75.70% and 77.57-92.59%, respectively. Especially, the CEs of pesticides with WCH and QR increased obviously. Importantly, neither WCH nor QR inhibited hatching of the critical insect natural enemy ladybird beetle at concentrations used in the field. This study provides a framework for assessment of tank-mix adjuvants in aerial sprays and directly demonstrates the value of specific adjuvants in improving pesticide bioavailability and minimizing associated environmental pollution.

Fast Determination of Fat-soluble Vitamins in Pharmaceutical Preparations by High-Performance Liquid Chromatography

Background: Vitamins are needed for the healthy functioning of the body. When these vitamins are not in sufficient amounts in the body, they are usually taken externally with pharmaceutical preparations. Taking vitamins into the body in the right amounts is possible by analyzing the amounts in pharmaceutical preparations with validated methods. Methods: In this study, a fast, simple, easily applicable, and selective normal-phase HPLC method was developed for the simultaneous determination of fat-soluble A, D3, E, and K1 vitamins in pharmaceutical preparations from syrup and tablets. Separation of the vitamins was carried out on a Zorbax CN column (250 x 4.6 mm, 5 µm) using a mixture of hexane-isopropyl alcohol (98:2, v/v) at 30°C column temperature and 1 ml/min flow rate. The detection wavelength is 280 nm. The developed method has been validated according to ICH Harmonised Tripartite Guideline Validation of Analytical Procedures: Text and Methodology Q2(R1) rules. Results: Calibration graphs are linear over the range of 10-1000 µg ml-1 , 1-50 µg ml-1 , 10-2000 µg ml-1 , 0.5-20 µg ml-1, and the limit of detection values were found to be 1.496, 0.280, 1.388 and 0.040 µg ml-1 for A, D3, E and K1 vitamins, respectively. Relative standard deviation values, which express within-day and between-day repeatability, were found below 2.54%. Average recovery values were also found at about 100.28, 101.46, 100.65, and 100.29% for A, D3, E, and K1 vitamins, respectively Conclusion: The developed and validated method was successfully applied to the simultaneous analysis of fat-soluble vitamins A, D3, E, and K1 in pharmaceutical preparations in syrup and tablet form.

Unveiling the role of electrolyte to promote enhanced proton storage stability in WO3 for energy storage

In the present work, we systematically investigate the phenomenon of electrochemical proton storage in WO3 and subsequently demonstrate a strategy for enhancing the cycle life for proton storage. It was carried out in three different electrolytes medium based on H3PO4, H2SO4 and HCl. It was found that although H3PO4 can promote better cycling stability and high rate capability than HCl and H2SO4, there still persists an issue in achieving large number of charge/discharge cycles. The typical proton storage capacitance of WO3 in 3.75 M H3PO4 is estimated to be around 288–346 F g−1 at a current rate of 0.5 A g−1 over 30 cycles. The cycling stability could, however, be significantly improved by the utilization of gel electrolyte which is basically a mixture of H3PO4 and polyvinyl alcohol (PVA) of different concentrations. For example, the estimated proton storage capacitance is around 287 F g−1 in 3.75 M H3PO4-PVA gel electrolyte (1:8 wt %) over 100 cycles at a current density of 0.5 A g−1. On the basis of the improved proton storage stability in the gel electrolyte, the electrochemical performance of a proton storage full cell with WO3 and V10O24.12H2O as electrodes is also illustrated. Another important revelation is the drastic reduction of the self-discharge rate of the full cell in the gel electrolyte in comparison to pristine aqueous medium electrolyte.

ZIF-8 metal organic framework, carboxymethylcellulose and polyvinyl alcohol bio-nanocomposite controlled-release phosphorus fertilizer: Improved P management and tomato growth

This study is concerned with the synthesis, characterization, and application of bio-nanocomposite films using a mixture of carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) integrated with zeolitic imidazolate type 8 (ZIF-8) nanoparticles (NPs). The advanced bio-nanocomposites were employed as a coating for triple superphosphate (TSP) fertilizers, and their impact on tomato plant growth was evaluated. The successful integration of ZIF-8 into the composite matrix was determined by distinct changes in Fourier transform infrared (FTIR) spectra, indicating significant structural modifications. Morphological analyses by scanning electron microscopy (SEM) revealed alterations in the surface characteristics of the CMC/PVA films. Furthermore, energy dispersive X-ray (EDX) analysis confirmed the elemental composition of the resulting nanocomposite. The precision-coated TSP fertilizers exhibited a notable enhancement in mechanical strength, as evidenced by their superior resistance to crushing. The coated TSP also exhibited a controlled release of phosphorus over time, prolonging the release of phosphorus for up to 9 days in water and 50 days in soil. In soil, the 0.5 % ZIF-8 NP coating delayed the release of phosphorus, with only 12.29 ± 2.75 % released after five days compared to 96.96 ± 2.03 % for uncoated TSP. The application of coated TSP fertilizers to tomato plants (of the MARIA variety) resulted in a 13.79 % increase in leaf number and a 15.83 % increase in plant height compared to uncoated TSP. This research underscores the pivotal role of advanced coating fertilizers in fostering sustainable and efficient agricultural practices, thereby making a substantial contribution to the advancement of innovative agrochemical solutions.

The Synthesis and Assembly Mechanism of Micro/Nano-Sized Polystyrene Spheres and Their Application in Subwavelength Structures.

The following study involved the utilization of dispersion polymerization to synthesize micron/nano-sized polystyrene (PS) spheres, which were then deposited onto a silicon substrate using the floating assembly method to form a long-range monolayer. Subsequently, dry etching techniques were utilized to create subwavelength structures. The adjustment of the stabilizer polyvinylpyrrolidone (PVP), together with changes in the monomer concentration, yielded PS spheres ranging from 500 nm to 5.6 μm in diameter. These PS spheres were suspended in a mixture of alcohol and deionized water before being arranged using the floating assembly method. The resulting tightly packed particle arrangement is attributed to van der Waals forces, Coulomb electrostatic forces between the PS spheres, and surface tension effects. The interplay of these forces was analyzed to comprehend the resulting structure. Dry etching, utilizing the PS spheres as masks, enabled the exploration of the effects of etching parameters on the resultant structures. Unlike traditional dry etching methods controlling RF power and etching gases, in the present study, we focused on adjusting the oxygen flow rate to achieve cylindrical, conical, and parabolic etched structures.

Novel design of low volume mobile phase paper chromatography

A novel design and set up of paper chromatography in the form of radial serpentine arms laying horizontally is proposed. The consumption of mobile phase is reduced to be 1 mL or less as compared to the tens of mL typically used in the conventional set ups for ascending paper chromatography, without any change in the order of the separated components. Greenness measurement based on the ChlorTox value is approximately 25, when comparing to a conventional system that consumes 25 mL of mobile phase. A digital image of the chemical separation makes data analysis more feasible as the image can be kept, and hence, extending the time for data analysis. The Retention Factor (Rf) value from a serpentine shaped stationary phase can be calculated based on measurement of linear distances of the solvent front and those travelled by each component, and converting them to arclengths using the mathematical equation of a catenary wave that produces that particular design. Proof of concept is demonstrated by the separation of food dyes using a two solvent system, where a nonvolatile salt solution is followed by a volatile organic solvent mixture of alcohols and base. Relationships between concentration, color intensity (RGB values), and zone arclength are also demonstrated which indicate possibility of quantitative study on the serpentine design using digital image analysis.

Advances in Extraction, Structure, and Physiochemical Properties of Sorghum Kafirin for Biomaterial Applications: A Review.

Kafirin is an endosperm-specific hydrophobic protein found in sorghum grain and the waste by-product from sorghum biorefineries known as sorghum dried distillers' grain with solubles (DDGS). Because of kafirin's poor nutritional profile (negative nitrogen balance, slow digestibility, and lack of some essential amino acids), its direct human use as a food is restricted. Nevertheless, increased focus on biofuel production from sorghum grain has triggered a new wave of research to use sorghum DDGS kafirin as a food-grade protein for biomaterials with diverse applications. These applications result from kafirin's unique chemical nature: high hydrophobicity, evaporation-induced self-assembling capacity, elongated conformation, water insolubility, and low digestibility. Aqueous alcohol mixtures have been widely used for the extraction of kafirin. The composition, structure, extraction methodologies, and physiochemical properties of kafirin, emphasising its biomaterial functionality, are discussed in detail in this review. The literature survey reveals an in-depth understanding of extraction methodologies and their impact on structure functionality, which could assist in formulating materials of kafirin at a commercial scale. Ongoing research continues to explore the potential of kafirin and optimise its utilisation as a functional biomaterial, highlighting its valuable structural and physicochemical properties. Further studies should focus on covering gaps in the research as some of the current structural understanding comes from data on zein protein from maize.

New Methodology for Modifying Sodium Montmorillonite Using DMSO and Ethyl Alcohol.

Modified clays with organic molecules have many applications, such as the adsorption of pollutants, catalysts, and drug delivery systems. Different methodologies for intercalating these structures with organic moieties can be found in the literature with many purposes. In this paper, a new methodology of modifying Sodium Montmorillonite clays (Na-Mt) with a faster drying time was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), BET, and thermogravimetric analysis (TG and DTG). In the modification process, a mixture of ethyl alcohol, DMSO, and Na-Mt were kept under magnetic stirring for one hour. Statistical analysis was applied to evaluate the effects of the amount of DMSO, temperature, and sonication time on the modified clay (DMSO-SMAT) using a 23-factorial design. XRD and FTIR analyses showed the DMSO intercalation into sodium montmorillonite Argel-T (SMAT). An average increase of 0.57 nm for the interplanar distance was found after swelling with DMSO intercalation. BET analysis revealed a decrease in the surface area (from 41.8933 m2/g to 2.1572 m2/g) of Na-Mt when modified with DMSO. The porosity increased from 1.74 (SMAT) to 1.87 nm (DMSO-SMAT) after the application of the methodology. Thermal analysis showed a thermal stability for the DMSO-SMAT material, and this was used to calculate the DMSO-SMAT formula of Na[Al5Mg]Si12O30(OH)6 · 0.54 DMSO. Statistical analysis showed that only the effect of the amount of DMSO was significant for increasing the interlayer space of DMSO-SMAT. In addition, at room temperature, the drying time of the sample using this methodology was 30 min.

Water-soluble arylhydrazone complexes based on Mn(II) and Cu(II) as catalysts for liquid-phase toluene oxidation

Novel hydrosoluble coordination compounds based on arylhydrazones of β-diketones and bearing first row transition metals, namely [Mn(μ-1κO1,2κO2-HL1)2(H2O)2]n (1) and [Cu(κO1O2N-L2)(DEA)] (2; DEA = diethanolamine), were synthesised and characterized. Their structural features were investigated using single crystal X-ray diffraction. The catalytic performance of the complexes was explored for liquid phase oxidation of toluene in homogeneous medium using aqueous tert‑butyl hydroperoxide (TBHP) and hydrogen peroxide (H2O2) as oxidants. Both catalysts demonstrated activity, producing a mixture of benzaldehyde, benzyl alcohol and benzoic acid. Under optimized conditions, in the presence of catalysts 1 and using an aqueous TBHP solution as oxidant, the oxidation of toluene yielded an overall 42.6 % of oxygenated products. Contrary to what has been regularly reported regarding selectivity for benzaldehyde, benzoic acid was the predominant product in this study (71 %).

Physical properties and diesel engine combustion of blends of alcohols with military jet fuel JP-5

Military operations may involve the use of jet fuel in a diesel engine, and the blending of alcohols with jet fuel is a way to introduce decarbonization into military operations. This study explored the effect of blending n-alcohols with navy jet fuel JP-5 on physical properties and combustion in a diesel engine. Blends containing 10 %, 20 %, and 30 % of ethanol, propanol, butanol, pentanol, hexanol, octanol, and one mixture of 10 % methanol/80 % octanol had densities (0.80 to 0.81 g/mL) that fell within military specifications for diesel. Most mixtures' flash points (16.5 to 65.0 °C) were below the military spec of 60 °C, which is higher than that of commercial aviation fuel. Most mixture viscosities (4.74 to 9.99 mm2/s) were within the jet fuel specifications at −20 °C but below the diesel fuel specification at 40 °C. Combustion of the alcohol/JP-5 mixtures in a diesel engine showed that increasing alcohol content lengthened the ignition delay (IGD). For some of the alcohols, shortening the carbon chain length on the alcohol led to longer IGDs with later combustion phasing that was most noticeable at lighter engine loads. The longer IGDs associated with the shorter alcohol fuels (and increased alcohol percentage) rapidly led to very high rates of energy release. The relative IGDs (IGD mixture/IGD JP-5) were less than 1.2 for the 10 % alcohol mixtures, between 1.0 and 1.4 for the 20 % alcohol mixtures, and between 1.0 and 1.9 for the 30 % alcohol mixtures excluding the 30 % ethanol mixture that did not combust. From the combustion metrics perspective, the longer carbon chain alcohols were most similar to the base jet fuel. Overall, the larger alcohols had physical properties and combustion metrics that were closer to those of the JP-5 jet fuel.

Efficacy Assessment of Five Policosanol Brands and Damage to Vital Organs in Hyperlipidemic Zebrafish by Six-Week Supplementation: Highlighting the Toxicity of Red Yeast Rice and Safety of Cuban Policosanol (Raydel®).

Policosanol is a mixture of long-chain aliphatic alcohols (LCAAs) derived from various plant and insect origins that are marketed by various companies with distinct formulations and brand names. Policosanols offer several beneficial effects to treat dyslipidemia and hypertension; however, a comprehensive functionality comparison of various policosanol brands has yet to be thoroughly explored. In the present study five distinct policosanol brands from different origins and countries, Raydel-policosanol, Australia (PCO1), Solgar-policosanol, USA (PCO2), NutrioneLife-monacosanol, South Korea (PCO3), Mothernest-policosanol, Australia (PCO4), and Peter & John-policosanol, New Zealand (PCO5) were compared via dietary supplementation (1% in diet, final wt/wt) to zebrafish for six weeks to investigate their impact on survivability, blood lipid profile, and functionality of vital organs under the influence of a high-cholesterol diet (HCD, final 4%, wt/wt). The results revealed that policosanol brands (PCO1-PCO5) had a substantial preventive effect against HCD-induced zebrafish body weight elevation and hyperlipidemia by alleviating total cholesterol (TC) and triglycerides (TG) in blood. Other than PCO3, all the brands significantly reduced the HCD's elevated low-density lipoprotein cholesterol (LDL-C). On the contrary, only PCO1 displayed a significant elevation in high-density lipoprotein cholesterol (HDL-C) level against the consumption of HCD. The divergent effect of PCO1-PCO5 against HCD-induced hepatic damage biomarkers, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), was observed. PCO1, PCO2, and PCO4 efficiently curtailed the AST and ALT levels; however, PCO3 and PCO5 potentially aggravated the HCD's elevated plasma AST and ALT levels. Consistently, the hepatic histology outcome revealed the least effectiveness of PCO3 and PCO5 against HCD-induced liver damage. On the contrary, PCO1 exhibited a substantial hepatoprotective role by curtailing HCD-induced fatty liver changes, cellular senescent, reactive oxygen species (ROS), and interleukin-6 (IL-6) production. Likewise, the histological outcome from the kidney, testis, and ovary revealed the significant curative effect of PCO1 against the HCD-induced adverse effects. PCO2-PCO5 showed diverse and unequal results, with the least effective being PCO3, followed by PCO5 towards HCD-induced kidney, testis, and ovary damage. The multivariate interpretation based on principal component analysis (PCA) and hierarchical cluster analysis (HCA) validated the superiority of PCO1 over other policosanol brands against the clinical manifestation associated with HCD. Conclusively, different brands displayed distinct impacts against HCD-induced adverse effects, signifying the importance of policosanol formulation and the presence of aliphatic alcohols on the functionality of policosanol products.

Synthesis of biodiesel based on alcohol mixtures

Today, the rapid depletion of traditional fuel sources and rapid global climate change in the environment has increased interest in alternative fuels. The current situation forces many countries to implement different strategies for the development of renewable energy sources. Therefore, the environmental safety of fuels is one of the key factors in ensuring the proper operation of internal combustion engines. These strategies include the synthesis of biodiesel as renewable energy, a promising fuel for diesel engines. The goal of the work was the synthesis of biodiesel fuel from cottonseed oil using a transesterification reaction in the presence of a mixture of small molecular weight alcohols, such as methanol, ethanol, n-propanol and i-propanol, in the presence of H2SO4 as a catalyst. The reaction time was 8 hours and the mixture of alcohols was: methanol (ethanol) (34%), propanol-1 (33%) and propanol-2 (33%), yielding 80 and 83%, respectively. From the 1H NMR spectra, the participation rates of alcohols in transesterification reactions were calculated. The exploitation properties (viscosity, density, ignition temperature, etc.) of the obtained biodiesels are presented according to ASTM standards.

Deep-eutectic-solvent modulation of self-assembled multi-responsive films based on polyvinyl alcohol/cellulose nanocrystal and grape skin red for highly sensitive food monitoring

To enhance the mechanics performance, sensitivity and response range of multi-responsive photonic films, herein, a facile method for fabricating multi-responsive films is demonstrated using the evaporative self-assembly of a mixture of grape skin red (GSR), cellulose nanocrystal (CNC), polyvinyl alcohol (PVA) and deep eutectic solvent (DES). The prepared materials exhibited excellent thermal stability, strain properties, solvent resistance, ultraviolet (UV) resistance and antioxidant activity. Compared to a pure PVA film, the presence of GSR strengthened the antioxidant property of the film by 240.1 % and provided excellent UV barrier capability. The additional cross-linking of DES and CNC promoted more efficient phase fusion, yielding a film strain of 41.5 %. The addition of hydrophilic compound GSR, wetting and swelling due to the DES and the surface inhomogeneity of the films rendered the multi-responsive films high sensitivity, wide response range and multi-cyclic stability in environments with varying pH and humidity. A sample application showed that a PVA/CNC/DES film has the potential to differentiate between fresh, sub-fresh and fully spoiled shrimps. The above results help in designing intelligent thin film materials that integrate antioxidant properties, which help in monitoring the changes in food freshness and food packaging.

Terahertz fingerprint reveals the effect of alcohols on sodium ions hydration shell.

Ion hydration plays a crucial role in numerous fundamental processes. Various spectroscopic methods are employed to investigate the slowing down of hydration bond dynamics in the proximity of both anions and cations. To date, most of these studies have primarily focused on the properties of binary systems. However, in comparison to ion-water binary systems, ternary systems that involve ions, water, and organic matter are more prevalent in nature and provide more realistic insights into biological processes. This study focuses on ion hydration in water and alcohol mixture using terahertz spectroscopy and x-ray diffraction (XRD). The results reveal a distinct behavior depending on the type of alcohol used. Specifically, the presence of both methanol and ethanol results in the disappearance of absorption peaks associated with NaCl hydrate at low temperatures. In contrast, tert-butanol does not exhibit such an effect, and isopropanol demonstrates a more complex response. By combining these terahertz spectroscopic findings with low-temperature XRD data, we gain insights into the formation, or lack thereof, of NaCl · 2H2O hydrate crystals. Crucially, our observations suggest a dominant correlation between the polarity of the alcohol molecules and its impact on the Na+ hydration. Strongly polar alcohols preferentially solvating the Na+ ion lead to the failure of hydrate formation, while weakly polar alcohols do not have this effect.

Exploring relaxation behaviors in Hydrogen-Bond networks within binary mixtures of propylene carbonate and primary alcohols through broadband dielectric spectroscopy and molecular dynamic simulation

This work investigates the dielectric properties and the relaxation behaviors of propylene carbonate (PC) and its binary mixtures with methanol and ethanol. A coaxial-circular cutoff waveguide junction was employed to characterize broadband dielectric spectra ranging from 0.1 GHz to 18 GHz, and a two-group Debye model was used to extract relaxation parameters. Excess thermodynamic parameters, Kirkwood orientational correlation factors, and Bruggeman factors for PC-alcohol mixtures were also analyzed and presented. These data provide insights into microscopic dynamic processes as the PC concentration in the mixtures gradually increases. These processes include the continuous disassociation of the alcohols’ hydrogen-bond (H-bond) networks, the formation of new PC-alcohol H-bond networks, the parallel alignment of heterogeneous dipoles, and a significant enhancement of the dielectric effect. Furthermore, a series of molecular dynamics (MD) simulations using the TraPPE-UA forcefield were conducted, and the obtained thermodynamic and electromagnetic parameters demonstrated good agreement with experimental results. Based on radial distribution functions, dipole–dipole spatial orientational correlations, and H-bond life times extracted from the MD simulations, we observed the gradual formation of PC-cage and alcohol-cluster microstructures in PC-rich mixtures. The data and physical insights provided in this work are expected to have practical implications in high-energy battery applications and the pharmaceutical industry.