Water Solvent System Research Articles

Epicatechin Isolated from Litchi chinensis Sonn. (Litchi) Fruit Peel Ethyl Acetate Extract Modulated Glucose Uptake in Chang Cells and Suppressed ROS Production in RAW 264.7 Macrophages.

Bioactive flavonoid epicatechin has been reported in the peel of litchi fruit but isolated from its hydroalcoholic extracts. This study isolated epicatechin with cellular glucose uptake modulatory and ROS production inhibitory properties from the ethyl acetate (EtOAc) extract using a bioassay-guided approach. The fruit peel was defatted with hexane and sequentially extracted using dichloromethane (DCM), EtOAc, methanol (MeOH) and water. In vitro phytochemical models, namely antioxidant (Fe3+ reducing, radical scavenging and anti-linoleic acid peroxidative) and glycaemic control (α-glucosidase and α-amylase inhibitory and glucose uptake modulatory), were employed for the bioassay-guided isolation, while the isolated compound was characterised using NMR and mass spectrometry and assessed for dose-dependent inhibition of α-glucosidase and lipopolysaccharide (LPS)-induced cellular ROS production, as well as modulation of cellular glucose uptake. Relative to the other extracts, the EtOAc extract had appreciable phenol and flavonoid contents, which perhaps influenced its potent anti-lipid peroxidative (65.0%) and α-glucosidase inhibitory (52.4%) effects. The α-glucosidase inhibitory potency of the fractions (1-8) from the EtOAc extracts correlated with their flavonoid contents, with fraction 5 outperforming other fractions. The fraction comprised a pool of fractions obtained from the DCM:MeOH:water (7:3:0.281 v/v/v) solvent system. LC-MS revealed the predominant presence of epicatechin in fraction 5, which was later isolated from one of the sub-fractions (sub-fraction 4) of fraction 5. This sub-fraction had stronger anti-lipid peroxidative (65.5%), α-glucosidase inhibitory (65.8%) and glucose uptake modulatory (38.2%) effects than the other sub-fractions from fraction 5, which could have been influenced by the isolated epicatechin. Moreover, the isolated epicatechin inhibited α-glucosidase (IC50 = 35.3 µM), modulated cellular glucose uptake (EC50 = 78.5 µM) and inhibited LPS-induced ROS production in RAW 264.7 macrophages in a dose-dependent fashion [IC50 = 18.9 µM; statistically comparable (p > 0.05) to ascorbic acid, IC50 = 9.57 µM]. Epicatechin from litchi peel EtOAc extract could potentiate glucose uptake modulatory, α-glucosidase inhibitory and ROS suppressive capacities, which could be influential in the use of litchi fruit peel for managing diabetes and associated oxidative damage.

Attraction behavior induces the aggregation and precipitation of organic dyes: Improving efficiency through co-treatment strategy

Organic dyes harm the environment through bioaccumulation, toxicity, water contamination, and persistence. Organic dyes are commonly charged species, while limited works reported the interaction behavior between the charges. In this study, seven typical organic dyes are selected to investigate the general rules of the aggregation-precipitation behaviors between cationic and anionic organic dyes at molecular scale. The maximum precipitation rates of organic dyes reached 96.0 % when the amount of positive charges of cationic dyes was stoichiometric to the negative charges of anionic dyes. The aggregation process is reversible in ethanol solvent and insensitive to temperature, indicating the aggregation behavior is a physical process. The aggregation behavior of cationic and anionic dyes in water and ethanol solvents was simulated at molecular scale. 94.9 % of water molecules dispersed out of the dye clusters within 20 picoseconds in the simulation, while only 0.8 % of ethanol dispersed under the same conditions. The inter-molecule van der Waals force of the ethanol-solvent system was higher than that of the water-solvent system, resulting in the failure of dyes aggregation in ethanol. This study proposed a concise strategy of mixing cationic and anionic dyes in charge balance to cause aggregation and co-precipitation of dyes to improve removal efficiency.

Ultrasound-assisted extraction of withanolides from Tubocapsicum anomalum: Process optimization, isolation and identification, and antiproliferative activity

Tubocapsicum anomalum, a Chinese medicinal plant rich in anti-tumor withanolides, requires efficient extraction methods. In this paper, an HPLC method was first established for the detection of withanolides, and gradient elution was carried out using a methanol–water solvent system. It was found that the content of withanolides was the highest in the leaves of T. anomalum, followed by the stems and fruits, and almost none in the roots. During the actual picking process, the quantity of leaves collected was relatively small, while the number of stems was the highest. Therefore, the Box-Behnken response surface method was used to optimize the ultrasonic-assisted extraction process of withanolides from the stems of T. anomalum. The optimal extraction conditions were determined as follows: the liquid–solid ratio was 20:1, the extraction solvent was 70 % ethanol, the ultrasonic power was 250 W, the ultrasonic time was 40 min, and the ultrasonic temperature was 50 °C. Under these conditions, the average yields of tubocapsenolide A (Te-A) and tubocapsanolide A (Ta-A) can reach 2.87 ± 0.12 mg/g and 1.18 ± 0.05 mg/g, respectively. We further compared extraction rates of two withanolides from different parts of T. anomalum using ultrasonic and traditional extraction methods. Ultrasonic extraction significantly increased rates, with the highest yields from leaves, followed by stems and fruits. The results show that ultrasonic optimization can improve extraction rate, reduce time, lower costs, enhance quality, and increase yield. Therefore, the optimized ultrasonic-assisted extraction process was adopted to extract the aerial parts of T. anomalum and separate the components. After optimization, the extract underwent several chromatographic separations to isolate eight previously undescribed withanolides (1–8) and two artificial withanolides (9–10), in addition to fifteen known compounds (11–25). Their structures were established through extensive spectroscopic data analysis. The compounds were evaluated for their antiproliferative effects against multiple cancer cell lines, including human hepatocellular carcinoma cells (HepG2, Hep3B, and MHCC97-H), human lung cancer cells (A549), human fibro-sarcoma cancer cells (HT1080), human chronic myeloid leukemia cells (K562), and human breast cancer cells (MDA-MB-231 and MCF7). Compounds 1–3, 5, 7, 11, 13, 15–16, and 22 displayed significant activity with IC50 values of 5.14–19.87 μM. The above results indicate that ultrasonic-assisted extraction technology can be used to obtain new withanolides more efficiently from T. anomalum, thereby enhancing the utilization rate of T. anomalum resources.

Green One-Pot Synthesis of Thiazole Scaffolds Catalyzed by Reusable NiFe2O4 Nanoparticles: In Silico Binding Affinity and In Vitro Anticancer Activity Studies.

A facile, green, one-pot multicomponent synthesis strategy was employed to fabricate novel thiazole scaffolds incorporating phthalazine, pyridazine, and pyrido-pyridazine derivatives (4a-4o). This synthetic route entailed the reaction of an α-halo carbonyl compound (1) with thiosemicarbazide (2) and various anhydrides (3a-3o), utilizing NiFe2O4 nanoparticles as a reusable catalyst in an ethanol:water (1:1) solvent system. The cytotoxicity of the synthesized compounds was meticulously assessed against three cancer cell lines, A375, HeLa, and MCF-7, employing IC50 values (μM) as the benchmark, and compared to the reference drug erlotinib. Compound 4n displayed remarkable efficacy against A375 (0.87 ± 0.31 μM), HeLa (1.38 ± 1.24 μM), and MCF-7 (1.13 ± 0.96 μM) cell lines, significantly surpassing erlotinib's IC50 values. Additionally, compounds 4k, 4l, 4m, and 4o demonstrated notable cytotoxicity across all tested cell lines, indicating their potential as effective anticancer agents. In silico docking studies against Hsp82 and Hsp90 proteins indicated that ligands 4k, 4m, 4c, 4j, 4o, and 4l had superior binding affinities compared to erlotinib. ADME analysis showed that compounds 4n, 4j, 4l, 4m, and 4o had favorable pharmacokinetic profiles, including nontoxicity, high human intestinal absorption, and low CYP inhibitory promiscuity. Structure-activity relationship analysis revealed that cyano and benzylidene substitutions significantly enhanced anticancer activity. Overall, the synthesized compounds, particularly 4n, demonstrated high efficacy, favorable binding interactions, and promising pharmacokinetic profiles, making them strong candidates for further development as anticancer agents.

Binary solvent-reinforced poly (vinyl alcohol)/sodium alginate double network hydrogel as a highly ion-conducting, resilient, and self-healing gel polymer electrolyte for flexible supercapacitors

We present a reliable approach for producing high-performance ion-conducting gel polymer electrolytes (GPEs) based on the sodium chloride (NaCl)-integrated dual network hydrogel of poly (vinyl alcohol)/sodium alginate (PVA/SA) using a binary solvent system of ethylene glycol (EG) and water, providing exceptional ionic conductivity, mechanical strength, and self-healing properties. Different GPEs were produced via the freezing-thawing method using different v/v% of EG and water (named PVA/SA/EG). The best PVA/SA/EG GPE provided a maximum ionic conductivity of 25 mS cm−1, astonishing mechanical strength of 0.42 MPa, exceptional stretchability of 462 %, and remarkable self-healing properties. The binary solvent system- and water-based GPEs were utilized in the construction of symmetric supercapacitors (SSCs) using carbon cloth electrodes and their electrochemical performance were compared. At a current density of 0.5 mA cm−2, the SSC prepared using the best PVA/SA/EG GPE demonstrated a high specific capacity of 577.21 mF cm−2, maintained 94.5 % capacitance after 5000 cycles at 1 mA cm−2, and provided an energy density of 80.14 mWh cm−2 while operating at a power density of 293.3 mW cm−2. The flexible SSC prepared based on this GPE demonstrated outstanding flexibility, while no significant decline in capacitive performance and ionic conductivity was detected when it was bent.

Unveiling the Factors Influencing Different Nucleation Pathways and Liquid-Liquid Phase Separation.

Exploring nucleation pathways has been a research hot spot in the fields of crystal engineering. In this work, vanillin as a model compound was utilized to explore the factors influencing different nucleation pathways with or without liquid-liquid phase separation (LLPS). A thermodynamic phase diagram of vanillin in the mixed solvent system of water and acetone from 10 to 55 °C was determined. It was found that the occurrence of LLPS might be related to different nucleation pathways. Under the guidance of a thermodynamic phase diagram, Raman spectroscopy and molecular simulation were applied to investigate the influencing factors of different nucleation paths. It was found that the degree of solvation is a key factor determining the nucleation path, and strong solvation could lead to LLPS. Additionally, the molecular self-assembly evolution during the crystallization process was further investigated by using small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS). The findings indicate that larger clusters with a diffuse transition layer may lead to LLPS during the nucleation process.

PyDFT-QMMM: A modular, extensible software framework for DFT-based QM/MM molecular dynamics.

PyDFT-QMMM is a Python-based package for performing hybrid quantum mechanics/molecular mechanics (QM/MM) simulations at the density functional level of theory. The program is designed to treat short-range and long-range interactions through user-specified combinations of electrostatic and mechanical embedding procedures within periodic simulation domains, providing necessary interfaces to external quantum chemistry and molecular dynamics software. To enable direct embedding of long-range electrostatics in periodic systems, we have derived and implemented force terms for our previously described QM/MM/PME approach [Pederson and McDaniel, J. Chem. Phys. 156, 174105 (2022)]. Communication with external software packages Psi4 and OpenMM is facilitated through Python application programming interfaces (APIs). The core library contains basic utilities for running QM/MM molecular dynamics simulations, and plug-in entry-points are provided for users to implement custom energy/force calculation and integration routines, within an extensible architecture. The user interacts with PyDFT-QMMM primarily through its Python API, allowing for complex workflow development with Python scripting, for example, interfacing with PLUMED for free energy simulations. We provide benchmarks of forces and energy conservation for the QM/MM/PME and alternative QM/MM electrostatic embedding approaches. We further demonstrate a simple example use case for water solute in a water solvent system, for which radial distribution functions are computed from 100ps QM/MM simulations; in this example, we highlight how the solvation structure is sensitive to different basis-set choices due to under- or over-polarization of the QM water molecule's electron density.

Oil/Water Biphasic Solvent System for the Eco-Extraction and Cosmetic Formulation of Bixa orellana L.

Annatto, obtained from the seeds of achiote (Bixa orellana L.), is a widely used orange pigment rich in bixin and other apocarotenoids. This work reports the optimisation of a green extraction method of pigments and antioxidant compounds from achiote as well as its integration in a one-step green extraction-cosmetic formulation process. A biphasic solvent system of water and oil was used to recover simultaneously polar polyphenols, and less polar compounds, such as δ-tocotrienol and bixin. The optimisation of the ultrasound assisted extraction is presented, as well as a comparison of different vegetable oils used as extraction solvents. The composition, physicochemical properties and antioxidant activity of the oils were studied and their extraction performance was compared. Refined sunflower oil proved to be a better solvent than virgin olive, jojoba, coconut and grapeseed oils. Both aqueous and oil phases displayed an interesting antioxidant capacity. The oil phase contained 0.9% of bixin, as well as minor apocarotenoids and δ-tocotrienol. Twelve compounds, mainly phenolics, were identified by UHPLC-DAD-HRMS/MS in the aqueous phase. Twenty-one volatile compounds were identified in the volatile fraction by SPME-GC-MS. Lastly, a one-step green process is proposed to combine the extraction and the cosmetic formulation of the bioactive compounds.

Effect of Organic Solvent on the Mass Transfer Mechanism of Coumarin 102 in a Single Octadecylsilyl Silica Gel/Organic Solvent-Water System by Laser Trapping and Fluorescence Microspectroscopy.

Understanding mass transfer kinetics within individual porous particles is crucial for theoretically explaining the retention and elution behaviors in chromatography and drug delivery. Using laser trapping and fluorescence microspectroscopy, we investigated the diffusion mechanism of coumarin 102 (C102) into single octadecylsilyl particle in acetonitrile (ACN)/water, N,N-dimethylformamide (DMF)/water, and 1-butanol (BuOH)/water solutions. The intraparticle diffusion behavior of C102 was evaluated using the spherical diffusion equation, allowing us to determine the intraparticle diffusion coefficients (Dintra): (8-10) × 10-9 cm2 s-1 for ACN, (10-16) × 10-9 cm2 s-1 for DMF, and (4-6) × 10-9 cm2 s-1 for BuOH. The obtained Dintra values were further analyzed using a pore and surface diffusion model. Thus, we revealed that the diffusion mechanism of C102 differed depending on the organic solvent: surface diffusion for ACN and DMF and pore and surface diffusions for BuOH were observed. This difference is attributed to the formation of a concentrated liquid phase of ACN and DMF at the interface of the alkyl chain and the bulk solution in the pore.

Extraction of curcumin from turmeric rhizome utilized by a surfactant-free microemulsion based on deep eutectic solvent

This study aimed to develop a surfactant-free microemulsion (SFME) which based on hydrophobic deep eutectic solvent (DES), intended to prospect its extraction effect of curcuminoids. A menthol and n-octanoic acid (ME-OA 1:2) hydrophobic DES is used as oil phase to SFME which have low viscosity, higher stability and better solubility for extracting curcuminoids. The hydrophobic DES was successfully formed which was demonstrated by 1HNMR and FT-IR. The ternary phase diagram and the microstructure of microemulsions was determined via visual titration, light scattering experiment and electrical conductivity. SFME consisting of ME-OA/Ethanol/H2O (1/7/2 mass ratio) had been constructed to investigate its ability to extract curcuminoids from turmeric rhizome utilizing HPLC. And the it was tested the extracted curcuminoids as a function of extraction time by UV–vis spectra. Using the single-factor experiments and response surface methodology (RSM), the optimal extraction conditions by ultrasound-assisted SFME were identified as follows: liquid/solid ratio of 12 g/g, extraction time of 63 min, and ultrasonic time (300 W) of 45 min. The total extraction amounts of curcuminoids could reach 61.39 mg/g powder under the best conditions, and the main factor to influence the final extraction effect was extraction time. The molecular dynamic simulation was performed to investigate the interaction between SFME and curcuminoids. Compared with the single component solvent system of ethanol, acetone, ME-OA and water, curcuminoids were stronger interaction energy with solvent molecules and higher hydrogen bond number in SFME. SFME formed the O/W structure of encapsulation solubilization for curcuminoids, in order to promote the dissolving of curcuminoids.

Base-free synthesis of renewable furan-2,5-dicarboxylic acid (FDCA) over an earth-abundant magnetic catalyst

Being a biobased alternative to petroleum-based terephthalic acid (TPA), furan-2,5-dicarboxylic acid (FDCA) requires a low-cost and efficient catalytic system for its commercialization. This study describes FDCA production using whey permeate powder (WPP)-derived 5-(hydroxymethyl)furfural (HMF) in a base-free system over a magnetically recyclable catalyst composed of earth-abundant metals (Mn and Fe). The impact of MnCl2·4 H2O loading on the iron core was studied at different levels and found optimal at the ratio of 1:1. The in-situ oxidation of HMF was carried out using ozone and t-BuOOH as the oxidants in a γ-valerolactone (GVL) -water solvent system. It was observed that the ozone pre-treatment (3 h at room temperature) of HMF increased the FDCA yield from 39.7 % (without ozonation) to 60 % at a reaction condition of 130 °C for 2 h. The concentration profiles for the intermediates formed during HMF to FDCA oxidation i.e., 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), furan-2,5-dicarbaldehyde (DFF), and 5-formyl-2-furancarboxylic acid (FFCA) were analyzed at different reaction temperatures to evaluate the reaction kinetics. The kinetic study revealed that the present solvent-catalytic system favored HMFCA formation over DFF due to the requirement of higher activation energy for the latter. The HMF to FDCA catalytic solvent was tested for WPP, which afforded an overall FDCA yield of 14.6 % at 130 °C in 120 min. In addition, the Mn1Fe1 consisted of mixed phases of Mn3O4, Mn2O3, MnO2, Fe2O3, and Fe3O4 and demonstrated variation in oxidation states for Mn (Mn3+↔Mn2+) and Fe (Fe2+↔Fe3+) species.

Anti-freezing and moisturizing PAA/PEDOT: PSS ionogels with multiple stimulus responses for flexible wearable electronics

Hydrogel is a promising material for wearable electronics due to its good mechanical properties, electrical conductivity and body adaptability. However, subzero freezing and water loss under high temperature or prolonged placement are great challenges for hydrogels. Here, polyacrylic acid / poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PAA/PEDOT: PSS) ionogels were designed by entangling PAA and PEDOT: PSS chains with each other in a binary solvent system of water and ionic liquid (IL) and chemical cross-linking by N, N’-methylene bisacrylamide (MBA). It has excellent mechanical properties (8.3 kPa, > 500 %), skin-adapted Young's modulus (<10 kPa), high conductivity (8.06 S·m−1), and strong adhesion (13.3 kPa). Ionogel has a sensitive response as a sensor (GF = 2.08, 0–200 %; GF = 3.64, 200–400 %; GF = 4.58, 400–510 %). Especially, the freeze-resistance and long-term moisturizing properties make ionogels exhibit long-lasting and robust utility. As a scalable application platform, we demonstrate the potential applications of this novel ionogel as a body-conformable electronic product in a series of conceptual demonstrations, including full range of human motion response, human–machine interaction (HMI), temperature signal detection and TENG device assembly.

Hydrothermal liquefaction of oil-palm-derived lignin to bio-oils for use as antioxidants in biodiesel

Lignin extracted from oil palm empty fruit bunch (EFB) fibers was used to produce a phenolics-rich bio-oil via hydrothermal liquefaction in pure water, or an ethanol–water (1:1 v v−1) solvent system, in a stirred batch reactor. The effects of liquefaction temperature (200–300 °C), pressure (10–40 bar), reaction time (0.5–3 h), solvent-to-lignin mass ratio (5–20), and the type of gas (N2, H2, CO2) in the reactor headspace were investigated on the yield and antioxidant properties of the bio-oil. The bio-oil and other products were characterized in detail. The conditions for obtaining a high yield of a bio-oil with a maximum phenolics content and the antioxidant activity were the following: ethanol–water solvent system with a solvent-to-lignin mass ratio of 10, 250 °C, 40 bar, H2 in the headspace, and a reaction time of 2 h. The bio-oil product contained multiple phenolics compounds, and proved to be an effective antioxidant additive in biodiesel made from palm oil. The bio-oil produced under the above specified conditions was a superior antioxidant than butylated hydroxytoluene (BHT), an oxidant used commercially. The bio-oil produced using water as the solvent instead of ethanol–water, was a less effective antioxidant.

Ionic Liquid/Water Binary Solvent Anti-Freezing Hydrogel for Strain and Temperature Sensors.

Hydrogels are widely applied in the flexible wearable electronic devices field owing to their skin-like stretchability, superb biocompatibility, and high conductivity retention under mechanical deformations. Nevertheless, hydrogels are prone to freezing at low temperatures and losing water at high temperatures, which seriously limits their practical applications. Herein, a binary solvent system of ionic liquid (1-ethyl-3-methylimidazolium chloride) and water was prepared to endow the ionic hydrogel high ionic conductivity (0.28 S m-1 at 25 °C), high transparency (94.26%), and superior freezing tolerance (-50 °C). The multiple hydrogen bonds formed among polymer chains, water, and ionic liquids significantly improved the mechanical properties of the ionic hydrogel, enabling excellent tensile properties (strain >1800%) and durability (1000 times at 100% strain). Moreover, the ionic hydrogel was further assembled into a dual-response sensor, which exhibited satisfactory sensitivity to both tension (gauge factor = 2.15 at 200% strain) and temperature (temperature coefficient of resistance = -1.845%/°C) and can be applied for human motion and body temperature monitoring. This study provides a versatile method for preparing multifunctional hydrogels with a wide range of applications and lays the groundwork for human movement detection and smart health care.

A Freeze‐Resistant, Highly Stretchable and Biocompatible Organohydrogel for Non‐Delayed Wearable Sensing at Ultralow‐Temperatures

AbstractWearable electronics based on conductive hydrogels (CHs) easily suffer from prolonged response times, reduced wearing comfort, shortened service lives, and impaired signal accuracy in cold environments, because conventional CHs tend to freeze at subzero temperatures and lose their flexibility, adhesion, transparency, and conductivity, which will limit their applications in extreme environments. Inspired by the way psychrotolerant creatures and superabsorbent materials interfere with the hydrogen bonding networks of water, a freeze‐resistant conductive organohydrogel (COH) is facilely fabricated. The synergy effect between charged polar terminal groups and a binary solvent system of water–ethylene glycol weakens the hydrogen bonding between water molecules and endows the COH with remarkable freezing tolerance (−78 °C). Additionally, the obtained COH is ultra‐stretchable (≈6185%), tough (9.2 MJ m−3), highly transparent (≈99%), self‐adhesive (10.2–27.8 kPa), and biocompatible. This versatile COH is assembled into a strain sensor and a well‐designed bracelet electrocardiogram sensor. Benefiting from the exceptional low‐temperature tolerance of the prepared COH, these devices exhibit fast response with delay‐free signals even at −40 °C. Overall, this work proposes a strategy to develop multifunctional COHs for supporting human health in cold environments.

Anti-Diabetic Activity And Anti-Oxidant Activity Of Kalanchoe Pinnata And Their Characterization Studies.

Species of Kalanchoe have been used as a remedy for various infectious diseases and cancer treatment. This study evaluates the anti-diabetic properties of the plant, Kalanchoe pinnata. Phytochemical components, anti-oxidant assays were also carried out. Phytochemical analysis showed the presence of alkaloids, flavonoids, steroids, phenolic compounds. The free radical scavenging activity was determined in which the ethanol extract showed the maximum inhibitory effect when compared with aqueous extract .Thin layer chromatography was done to determine the compound in a solvent system of methanol, acetic acid, formic acid and water in the ratio 3:1:1:0.5 . Characterization of the leaf extract was done by UV-visible spectroscopy which showed the peak between 300-350nm. FTIR analysis showed the presence of the various functional group present in the plant. Aqueous and ethanol extract was subjected to α-amylase inhibitory effect and α-glucosidase inhibitory effect to find the antidiabetic potential activity of the plant extract.

CO2 adsorption mechanisms at the ZIF-8 interface in a Type 3 porous liquid

Porous liquids (PLs) are an attractive material for gas separation and carbon sequestration due to their permanent internal porosity and high adsorption capacity. PLs that contain zeolitic imidazole frameworks (ZIFs), such as ZIF-8, form PLs through exclusion of aqueous solvents from the framework pore due to its hydrophobicity. The gas adsorption sites in ZIF-8 based PLs are historically unknown; gas molecules could be captured in the ZIF-8 pore or adsorb at the ZIF-8 interface. To address this question, ab initio molecular dynamics was used to predict CO2 binding sites in a PL composed of a ZIF-8 particle solvated in a water, ethylene glycol, and 2-methylimidazole solvent system. The results show that CO2 energetically prefers to reside inside the ZIF-8 pore aperture due to strong van der Waals interactions with the terminal imidazoles. However, the CO2 binding site can be blocked by larger solvent molecules that have greater adsorption interactions. CO2 molecules were unable to diffuse into the ZIF-8 pore, with CO2 adsorption occurring due to binding with the ZIF-8 surface. Therefore, future design of ZIF-based PLs for enhanced CO2 adsorption should be based on the strength of gas binding at the solvated particle surface.

Robust integration of "top-down" strategy and triple-structure design for nature-skin derived e-skin with superior elasticity and ascendency strain and vibration sensitivity

The rapid advancement of bio-integrated electronics in recent years has been paralleled by increased interest in the research of stretchable, elastic, conductive, and multi-dimensional sensing electronic skin (e-skin) due to its potential integration with electronic devices and soft tissues. In this work, we presented the fabrication of a nature-skin derived e-skin, denoted as S-P/G@PU e-skin, achieved through an on-demand "top-down" strategy and a triple structure design, employing integrated in-situ polymerization, impregnation, and encapsulation techniques. The collagen fibers weaved hierarchical 3D structure of natural skin, was strategically employed to host conductive polypyrrole and combined with a binary solvent system of glycerin and water. Subsequently, this composite natural skin was coated with polyurethane films, resulting in the engineering of the S-P/G@PU e-skin. This innovative e-skin exhibited remarkable properties, including high tensile strength (8.76 MPa), excellent elasticity (0–180 %), anti-freezing capacity, moisture retention, substantial conductivity (6.3 S/m), and outstanding multi-dimensional sensing capabilities. Importantly, the S-P/G@PU e-skin functioned as both a slow adaptive resistance strain sensor and a fast adaptive single-electrode triboelectric nanogenerator, making it a versatile sensing system that enabled real-time monitoring of various physiological signals from the human body and wide-frequency vibration signals from devices such as cellphones and motors. This study serves as a proof of concept for transforming nature-skin into e-skin, showcasing the potential for integrated wearable electronics, artificial intelligence, and human-machine interfaces.

Significantly improve film formability of acetylated xylans by structure optimization and solvent screening

Acetylated xylans have great potential in fabricating functional film and coating materials, which need a good solubility/dispersibility and film formability in an easily evaporable solvent. However, the changes of film formability with degree of substitution by acetyls (DSAc) in different solvent systems for xylans have not been extensively studied, which limit the application of acetylated xylans in film materials. In this study, acetylated xylans with DSAc of 0–2 were prepared and the effects of acetyl groups on solubility/dispersibility, crystallinity and film formability of xylans in water and chloroform solvent systems were investigated. Due to the change of polarity, xylans with DSAc of 0–0.62 are only soluble in water solvents, while xylans with DSAc of 1.13–2 are only soluble in chloroform/ethanol (70/30 v/v) organic solvents. We have found that the film formability of acetylated xylans is highly related to their solubility and crystallization. Film formable xylans all had good solubility in the cast solvents. However, although with good solubility, xylans with DSAc of 0–0.3 and DSAc of 1.76–2 cannot form intact films, which is due to the forming of xylan hydrate crystals and xylan diacetate crystals. With the increase of DSAc, the mechanical property of xylan film increases initially at low DSAc and decreases at high DSAc. This study provides theoretical basis for applying xylans and their derivatives in advanced functional film and coating materials with great biocompatibility and biodegradability.

Solid-liquid equilibrium, molecular simulation and thermodynamic properties of sulfaguanidine in pure and binary solvents from 288.15 K to 343.15 K

The solubility of sulfaguanidine(SG) in water, methanol, ethanol, n-propanol, isopropanol, n-butanol and binary solvent systems (water + methanol/n-propanol) was determined by the synthetic method at local pressure values in the temperature range of 288.15 K to 343.15 K. The experimental data were compiled and plotted, and it can be seen that the solubility of SG in the six pure solvents and two binary solvent systems in the selected temperature range increased monotonically with increasing temperature. The solubility of SG in pure solvents was in the order of methanol > ethanol > n-propanol ≈ isopropanol > n-butanol > water. The solubility of SG in the mixture of water + methanol increased with the composition of the benign solvent, while the solubility in the mixture of n-propanol + water increased first and then decreased with the increase of the benign solvent. In addition, the Van’t Hoff model, Apelblat model, λh model and Wilson model were cited to correlate the solubility data of SG in pure and binary solvents, and additionally the binary models Apelblat-Jouyban-Acre (A-JA) model and Van't Hoff-Jouyban-Acre model were used to fit the solubility of SG in two binary solvents. The RAD and RMSD values show that the chosen models both show good correlation. The solvent effect was analyzed using the KAT-LSER model and the solubility of SG in the solvents used was mainly influenced by non-polarity and viscosity. After that, the inter-molecular forces of SG were explored using Hirshfeld surface analysis and a two-dimensional fingerprint was plotted. Finally, the thermodynamic properties of SG in all solvent systems, including Gibbs free energy, entropy and enthalpy, were calculated using Van’t Hoff equation and the experimentally measured solubility data.