Water Binary Solvent Research Articles

Solubility determination and thermodynamic modelling of verapamil hydrochloride in methanol-water binary solvent systems from 293.15 K to 323.15 K

Verapamil Hydrochloride is a key calcium channel blocker used to treat cardiovascular disorders and prevent cluster headaches by inhibiting calcium influx, thus improving cardiovascular health. The solubility of Verapamil Hydrochloride (VH) in methanol + water binary solvent systems were studied using a gravimetric method at temperatures from 293.15 K to 323.15 K under atmospheric pressure. The solubility increased with temperature and methanol content, with the highest mole fraction solubility at a 0.90 methanol mole fraction and the lowest at 0.10. Various models, including Apelblat, Van't Hoff, modified Jouyban–Acree, and CNIBS/R-K, were used to calculate theoretical solubility, with RAD and RMSD assessing the model accuracy. Thermodynamic analysis indicated that VH dissolution is endothermic and entropy-driven. This data is valuable for optimizing VH purification and crystallization processes in the pharmaceutical industry.

Environmentally stable and rapidly polymerized tin-tannin catalytic system hydroxyethyl cellulose hydrogel for wireless wearable sensing

In recent years, flexible sensors constructed mainly from hydrogels have played an indispensable role in several fields. However, the traditional hydrogel preparation process involves complex and time-consuming steps and the freezing or volatilization of water in the water gel in extreme environments greatly limits the further use of the sensor. Therefore, an ionic conductive hydrogel (SnHTD) was designed, which was composed of tannic acid (TA), metal ions Sn2+, hydroxyethyl cellulose (HEC), and acrylamide (AM) in a deep eutectic solvent (DES) and water binary solvent. It is worth noting that the gel time is shortened to less than 3 min by introducing the Sn-TA redox system. The addition of DES makes the hydrogel have a wide temperature tolerance range (−20 to 60 °C) and the ability to store for a long time (30 days). The introduction of HEC increased the tensile stress of hydrogel from 140.17 kPa to 219.89 kPa. Additionally, the hydrogel also has high conductivity, repeatable adhesion and UV shielding properties. In general, this research opens up a new way for room temperature polymerization of environmentally resistant hydrogel materials and effectively meets the growing demand for wireless wearable sensing.

Single proton anti-freezing hydrogel electrolyte with enhanced ion migration number enabling high-performance supercapacitor

Compared with traditional binary ion electrolytes, single-ion electrolytes have higher ion migration number and can avoid concentration polarization. In this work, single proton hydrogel electrolytes were prepared by one-step free radical polymerization of acrylamide and 2-acrylaminoamido-2-methyl-1-propane sulfonic acid in ethylene glycol (EG)/water binary solvent. The electrolyte possesses good mechanical strength and excellent anti-freezing ability. A high conductivity of 1.28 mS cm−1 at −40 °C is achieved by adjusting monomer ratio and EG content. The proton hopping along the ion channel formed by the anionic polymer chain and the Grotthuss transport are responsible for the high conductivity. An extremely high ion migration number of 0.87 is obtained. The fixed anionic group endows the hydrogel electrolyte with good anticorrosion ability. The hydrogel electrolyte assembled supercapacitor (SC) exhibits excellent electrochemical performance in a wide temperature range from −40 °C to 60 °C and can be stored at −30 °C for 10 months without capacitance attenuation. The capacitance retention rate of the SC is as high as 92% after 15,000 cycles at both room temperature and − 40 °C. The single proton hydrogel electrolyte provides a new route for the further development of storage device based proton transport.

Methanol-water manipulated polymorphic nucleation of L-Ornithine-L-Aspartate

Screening for a suitable polymorph is crucial in pharmaceutical engineering. Here we reported the polymorphic nucleation of L-Ornithine-L-Aspartate (LOLA) in a methanol–water binary solvent. A new metastable form named monohydrate was discovered, which was found affected the nucleation of LOLA anhydrate. The antisolvent crystallization experiments showed that when the molar fraction of methanol was less than 0.387 or more than 0.448, the anhydrate LOLA nucleated, while it was between 0.390–0.416, the monohydrate appeared. Specifically, the isolated water molecules were the key parameter for polymorphic nucleation of LOLA. When methanol was less or more, it was insufficient to break the water hydrogen bonding network or enough to form methanol–water network, both could cause less isolated water, thus the anhydrate nucleated. On the contrary, when the methanol content was 0.390–0.416, methanol molecules could occupy some spatial sites in the water network resulting in more isolated water, thus the monohydrate appeared.

Solubility measurements and molecular dynamics simulations of perphenazine (form I) in three binary solvent systems

This study aimed to investigate the perphenazine (form I)’s solubility in three binary solvent systems: acetone + water, n-propanol + water, and N,N-dimethylformamide (DMF) + water, within the temperature range of 278.15 K to 318.15 K. The solubility data were obtained using a dynamic method and fitted using four models: the NRTL model, modified Apelblat equation, CNIBS/R-K model, and Jouyban-Acree model. All four models provided satisfactory fitting results, with the CNIBS/R-K model exhibiting the best performance. In all cases, it was observed that the solubility of perphenazine (form I) exhibited a positive correlation with temperature while keeping the solvent composition constant. Specifically, in the DMF + water binary solvent system, the solubility of perphenazine (form I) increased with higher mass fractions of the positive solvent. Additionally, the phenomenon of co-solvency was observed when perphenazine (form I) was dissolved in the acetone + water and n-propanol + water binary solvent systems. To gain insights into the intermolecular interactions within the perphenazine (form I) crystal, Hirshfeld surface (HS) analysis was employed. The Dmol3 module was used to calculate the electrostatic potential of perphenazine molecules, followed by molecular dynamics simulation, analysis of the solute–solvent and solvent–solvent radial distribution functions (RDF), and calculation of solvation free energy. Overall, this study enhances the understanding of the dissolution behavior of perphenazine (form I) and provides valuable data to support further investigations into its crystallization process.

A novel highly stretchable, freeze-resistant, and recyclable organohydrogel by waterborne polyurethane and DMSO-H2O binary solvent enhanced for multifunctional sensors

Conductive hydrogels have gained significant attention for wearable devices in recent years. However, hydrogel suffers from limitations such as poor stretchability, freezing under cold climates, and drying out in harsh environments, which restrict its practical applications. To address these issues. We synthesize waterborne polyurethane (WPU) and add it to the polyvinyl alcohol (PVA) hydrogel to enhance its mechanical properties. Additionally, DMSO is introduced to the system, aiming to enhance the environmental stability of the hydrogel through its interaction with water. Hence, we prepare a novel organohydrogel by incorporating WPU into PVA in a dimethyl sulfoxide (DMSO)-water (H2O) binary solvent system by one-pot method. The addition of DMSO and WPU enhances the mechanical properties of the organohydrogel, resulting in high mechanical strength (1.27 MPa), excellent stretchability (874%), and superior toughness (3.62 MJ/m3). In addition, the organohydrogel presents reliable freeze resistance and water retention properties due to DMSO interaction with water. More significantly, the organohydrogel can be recycled and reshaped into various shapes through a simple process. The reconstructed organohydrogel still has the original's mechanical properties and sensing capabilities and can continue to be used in flexible electronic devices. Moreover, the organohydrogel is developed for flexible multifunctional sensors, exhibiting high sensitivity (G = 1.89), a rapid response time (141 ms), and exceptional fatigue resistance (100 cycles). Notably, the sensor signals remain stable even after storage in extreme conditions. This study expands the working field of flexible hydrogel sensors and provides a new idea for the sustainable development of next-generation flexible hydrogel sensors.

Highly stretchable anti-freeze hydrogel based on aloe polysaccharides with high ionic conductivity for multifunctional wearable sensors

Conductive hydrogels have limitations such as non-degradability, loss of electrical conductivity at sub-zero temperatures, and single functionality, which limit their applicability as materials for wearable sensors. To overcome these limitations, this study proposes a bio-based hydrogel using aloe polysaccharides as the matrix and degradable polyvinyl alcohol as a reinforcing material. The hydrogel was crosslinked with borax in a glycerol–water binary solvent system, producing good toughness and compressive strength. Furthermore, the hydrogel was developed as a sensor that could detect both small and large deformations with a low detection limit of 1 % and high stretchability of up to 300 %. Moreover, the sensor exhibited excellent frost resistance at temperatures above −50 °C, and the gauge factor of the hydrogel was 2.86 at 20 °C and 2.12 at −20 °C. The Aloe-polysaccharide-based conductive hydrogels also functioned effectively as a wearable sensor; it detected a wide range of humidities (0–98 % relative humidity) and exhibited fast response and recovery times (1.1 and 0.9 s) while detecting normal human breathing. The polysaccharide hydrogel was also temperature sensitive (1.737 % °C−1) and allowed for information sensing during handwriting.

One pot synthesis of hydrophobic nanochitin aerogel via tert-butyl alcohol/water binary solvents as antibacterial and renewable oil superabsorbent

In this study, hydrophobic nanochitin aerogels are synthesized via one-pot synthesis strategy and subsequent freeze-drying technique, employing nanochitin, hexanal and formaldehyde as primary components. The tert-butyl alcohol (TBA)/water binary solvents are found efficient for well mixing of hydrophilic nanochitin and hydrophobic hexanal, which is fundamental for fabricating hydrophobic aerogels with water contact angle as high as 105°. Schiff base reaction between amino groups in nanochitin and aldehyde groups in hexanal is believed to be the main reason for the successful hydrophobization of nanochitin aerogels. Additionally, formaldehyde is employed to enhance the mechanical properties of aerogels via ice templated crosslinking technique. Nanochitin aerogels prepared in this work possess surface area as high as 237 m2 g−1, which are believed benefiting from the TBA/water binary solvents with lower density, smaller ice crystal and convenience in freeze-drying. The ultralow density, ultrahigh porosity, and hydrophobicity nature also lead to the advanced oil adsorption (as high as 210 g g−1) of nanochitin aerogels. The simple preparation process, nature sustainability and excellent adsorption performance is believed rendering nanochitin aerogels as a viable alternative for the remediation of oil spills.

Self-Healable, Adhesive, Anti-Drying, Freezing-Tolerant, and Transparent Conductive Organohydrogel as Flexible Strain Sensor, Triboelectric Nanogenerator, and Skin Barrier.

Conductive hydrogels have attracted tremendous interest in the construction of flexible strain sensors and triboelectric nanogenerators (TENGs) owing to their good stretchability and adjustable properties. Nevertheless, how to simultaneously achieve high transparency, self-healing, adhesion, antibacterial, anti-freezing, anti-drying, and biocompatibility properties through a simple method remains a challenge. Herein, a transparent, freezing-tolerant, and multifunctional organohydrogel (PAOAM-PDO) as electrode for strain sensors and TENGs was constructed through a free radical polymerization in the 1,3-propanediol (PDO)/water binary solvent system, in which oxide sodium alginate, aminated gelatin, acrylic acid, and AlCl3 were used as raw materials. The obtained PAOAM-PDO exhibited good transparency (>90%), self-healing, adhesiveness, antibacterial property, good conductivity (1.13 S/m), and long-term environmental stability. The introduction of PDO endowed PAOAM-PDO with freezing resistance with a low freezing point of -60 °C, and PAOAM-PDO could serve as a protective skin barrier to prevent frostbite at low temperature. PAOAM-PDO could be assembled as strain sensors to monitor heterogeneous human movements with high strain sensitivity (gauge factor of 7.05, strain = 233%). Meanwhile, PAOAM-PDO could be further fabricated as a TENG with a "sandwich" structure in single electrode mode. Moreover, the resulting TENG achieved electrical outputs with simple hand tapping and served as a self-powered device to light light-emitting diodes. This work displays a feasible strategy to build environment-tolerant and multifunctional organohydrogels, which possess potential applications in the wearable electronics and self-powered devices.

High-Strength, Freeze-Resistant, Recyclable, and Biodegradable Polyvinyl Alcohol/Glycol/Wheat Protein Complex Organohydrogel for Wearable Sensing Devices.

The application of flexible wearable sensing devices based on conductive hydrogels in human motion signal monitoring has been widely studied. However, conventional conductive hydrogels contain a large amount of water, resulting in poor mechanical properties and limiting their application in harsh environments. Here, a simple one-pot method for preparing conductive hydrogels is proposed, that is, polyvinyl alcohol (PVA), wheat protein (WP), and lithium chloride (LiCl) are dissolved in an ethylene glycol (EG)/water binary solvent. The obtained PVA/EG/WP (PEW) conductive organohydrogel has good mechanical properties, and its tensile strength and elongation at break reach 1.19 MPa and 531%, respectively, which can withstand a load of more than 6000 times its own weight without breaking. The binary solvent system composed of EG/water endows the hydrogel with good frost resistance and water retention. PEW organohydrogel as a wearable strain sensor also has good strain sensitivity (GF = 2.36), which can be used to detect the movement and physiological activity signals in different parts of the human body. In addition, PEW organohydrogels exhibit good degradability, reducing the environmental footprint of the flexible sensors after disposal. This research provides a new and viable way to prepare a new generation of environmentally friendly sensors.

High-strength, anti-freeze, transparent and recyclable composite organohydrogel for flexible strain sensor

Hydrogels have received widespread attention as flexible strain sensors in the fields of human motion detection and health monitoring. However, the presence of large amounts of water in traditional hydrogels leads to poor mechanical properties and low anti-freezing, which severely limits their applications. Herein, a novel PVA/DMSO/CMC/AlCl3/TA/LiCl (PDCATL) composite organo-hydrogel was developed by freeze-thaw and salt solution immersion methods, using polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), aluminum chloride hexahydrate (AlCl3·6H2O) and tannic acid (TA) dissolved in a dimethyl sulfoxide (DMSO)/water binary solvent. The PDCATL organohydrogel exhibited high tensile strength and elongation at break (up to 1.90 MPa and 587%), which can withstand >6000 times its own weight, good anti-freezing and excellent transparency (>90% light transmission). The PDCATL organohydrogel still maintained excellent transparency, flexibility, recyclability and signal sensing capability at low temperatures (−20 °C). The PDCATL organohydrogel also had good strain sensitivity (GF = 1.82) as a wearable strain sensor and can be used to detect motion and physiological activity signals in various parts of the human body. This study will provide a viable avenue for the application of hydrogel sensors in the fields of visual human-computer interaction, wearable sensors, visual optical detection and medical health detection.

Ethanol–water binary solvent affects phenolic composition and antioxidant ability of Pistacia lentiscus L. fruit extracts: a theoretical versus experimental solubility study

Ethanol–water binary solvent affects phenolic composition and antioxidant ability of Pistacia lentiscus L. fruit extracts: a theoretical versus experimental solubility study

Highly robust and sensitive dual-network freeze-resistant organic hydrogel thermocells

Thermocells (TECs) are eco-friendly and ideal power-generation devices that sustainably convert waste heat into electricity to power wearable electronics. However, their poor mechanical properties, limited operating temperature, and low sensitivity limit their practical application. Hence, K3/4Fe(CN)6 and NaCl thermoelectric materials were introduced into a bacterial cellulose-reinforced polyacrylic acid double-network structure and permeated into a glycerol (Gly)/water binary solvent to prepare an organic thermoelectric hydrogel. The resulting hydrogel had a tensile strength of approximately 0.9 MPa and a stretched length of approximately 410 %; moreover, it worked stably even in the stretched/twisted state. Owing to the introduction of Gly and NaCl, the as-prepared hydrogel exhibited excellent freezing tolerance (− 22 °C). In addition, the TEC also demonstrated excellent sensitivity (~13 s). Good environmental stability and high sensitivity make this hydrogel TEC a promising candidate for thermoelectric power-generation/temperature-monitoring systems.

Solubility and Thermodynamics Profile of Benzethonium Chloride in Pure and Binary Solvents at Different Temperatures.

Benzethonium chloride (BTC) has various applications in several industries. The solubility and solution thermodynamic properties of BTC were measured. The solubility of BTC in methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, water, dimethyl sulfoxide, acetic acid, and dimethyl formamide neat solvents and methanol + water and ethanol + water binary solvents at 298.15-318.15 K over an atmospheric pressure was measured. The solubility data of BTC is positively related to the temperature in all selected solvents. The solubility data was fitted by the Apelblat model, λh model, Yaws model, Van't Hoff equation, CNIBS/R-K model, and modified Jouyban-Acree equation. The RMSD and ARD were chosen to evaluate the fitting of each model. The dissolution thermodynamic parameters, enthalpy of the solution, entropy of the solution, and Gibbs energy of the solution were calculated. The solubility data and dissolution thermodynamic parameters of BTC will provide significant guidance for purification, crystallization, and separation in various areas.

Determination of Solubility and Thermodynamic Analysis of Solubility Behavior of 2,5-Furandicarboxylic Acid in Water and Ether Binary Solvent System

2,5-Furandicarboxylic acid (FDCA) is a promising biomass-derived monomer, and the study of FDCA dissolution behavior is of paramount importance to its purification. In this study, the solubility of FDCA in four different ethers (1,4-dioxane, tetrahydrofuran, 1,2-dimethoxyethane, and diethylene glycol dimethyl ether), as well as four binary solvent systems containing these above ethers with water, was measured by a gravimetric method. The solubility of FDCA could be improved in binary solvent systems as compared to corresponding pure solvents. More interestingly, the solubility of FDCA increased first and then gradually dropped back with the increasing mole fraction of water in binary solvent systems. The KAT-LSER model was used to explore the influence of solvent effect on solubility. The Hansen solubility parameter was utilized to probe the solute–solvent molecular interactions. Apelblat equation, van’t Hoff equation, λh equation, Wilson model, and nonrandom two-liquid model were applied to analyze the experimental solubility data in pure ether solvents and binary solvent systems. Furthermore, the dissolution thermodynamic characteristics of FDCA in particular binary solvent systems were analyzed by the van’t Hoff equation, which revealed that the dissolving process of FDCA is endothermic, entropy-driven, and spontaneous in the other three examined solvent systems, with the exception of the 1,4-dioxane/water mixture.

A Facile One-Pot Preparation and Properties of Nanocellulose-Reinforced Ionic Conductive Hydrogels.

Nanocellulose-reinforced ionic conductive hydrogels were prepared using cellulose nanofiber (CNF) and polyvinyl alcohol (PVA) as raw materials, and the hydrogels were prepared in a dimethyl sulfoxide (DMSO)/water binary solvent by a one-pot method. The prepared hydrogels were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The mechanical properties, electrical conductivity, and sensing properties of the hydrogels were studied by means of a universal material testing machine and LCR digital bridge. The results show that the ionic conductive hydrogel exhibits high stretchability (elongation at break, 206%) and firmness (up to 335 KPa). The tensile fracture test shows that the hydrogel has good properties in terms of tensile strength, toughness, and elasticity. The hydrogel as a conductor medium is assembled into a self-powered strain sensor and the open-circuit voltage can reach 0.830 V. It shows good sensitivity in the bend sensing testing, indicating that the hydrogel has good sensing performance. The water retention and anti-freezing performance experiments show that the addition of dimethyl sulfoxide solvents can effectively improve the anti-freezing and water retention properties of hydrogels.

From grape seed extracts to extremely stable strain sensors with freezing tolerance, drying resistance and anti-oxidation properties

Conductive hydrogels were fascinating stretchable conductive materials that have found widespread application in electronic skin, wearable sensors and soft robots. Nonetheless, similar to conductive materials, conductive hydrogels experience severe performance degradation in strong UV environments and cold, dry climates, which severely restricts their practical applications. Using grape seed extract polymer (GSP), sodium chloride (NaCl), and a DMSO/ water binary solvent system, a type of hydrogel with a variety of fascinating multifunctional properties was quickly fabricated. The presence of GSP and NaCl endows hydrogel materials with remarkable UV-blocking (~82%), DPHH radical scavenging ability (~76.33%) and conductivity, allow them to be utilized as sensors. In addition, a DMSO/water binary solvent provides the hydrogel with superior long-term drying resistance and freezing tolerance, as well as excellent stretchability (>300%) and good conductivity even at -23 °C. This work investigates the potential of dynamic plant catechol chemistry in the field of hydrogel materials and anticipates that it will enable flexible sensors capable of adjusting to a variety of complex environments. • A Conductive hydrogel was designed by PVA and grape seed extract polymer (GSP). • GSP was used as a green source of antioxidant. • The hydrogel exhibited good UV-blocking and free radical scavenging properties. • The hydrogel exhibited excellent anti-drying and anti-freezing properties.

Crystallization thermodynamics of 2,4(5)-dinitroimidazole in binary solvents

2,4(5)-Dinitroimidazole (2,4(5)-DNI) is an important organic intermediate, and itself can also be used for energetic material. In this work, the solubility of 2,4(5)-DNI in (methanol + water, acetonitrile + water, acetone + water) binary solvents were measured by using a dynamic test method from 278.15 K to 323.15 K under 101.1 kPa. The Jouyban–Acree model, van’t Hoff–Jouyban–Acree model, Apelblat–Jouyban–Acree model, Ma model, and Sun model were used to correlate the experimental data. The values of relative average deviation (RAD) and root-mean-square deviation (RMSD) were very small, indicating that the error between the experimental value and the correlated value was very small. The thermodynamic parameters such as dissolution enthalpy, dissolution entropy and Gibbs energy were calculated based on solubility data. High-purity of 2,4(5)-DNI was efficiently obtained by using cooling and dilution crystallization method.

Measurement and Correlation of the Solubility of Florfenicol in Four Binary Solvent Mixtures from T = (278.15 to 318.15) K

Florfenicol is an excellent antibiotic and is widely used in animal bacterial diseases. However, its poor water solubility leads to various problems, such as poor absorption and bioavailability. The development of nanocrystals is one of the most useful methods for solubilizing florfenicol, which often requires solubility data of florfenicol in different mixed solvents. In this work, the solubility of florfenicol was determined by the gravimetric method in methanol + water, ethanol + water, 1-propanol + water, and isopropanol + water binary solvents at temperatures from 278.15 to 318.15 K. In these four mixed solvents, the solubility of florfenicol increased with the increase in temperature. The solubility of florfenicol in methanol + water mixed solvent increases with the decrease in water ratio, while the solubility of florfenicol in ethanol + water, 1-propanol + water, or isopropanol + water mixed solvents increased first and then decreased with the decrease in water ratio, indicating a cosolvency phenomenon. The modified Apelblat model, CNIBS/R-K model, Jouyban–Acree model, and NRTL model were used to correlate the solubility data of florfenicol in four binary solvents. RMSD values indicated that the calculated values are in good agreement with the experimental solubility data for all four models, among which the CNIBS/R-K model provides the best correlation.

Frost-resistant and ultrasensitive strain sensor based on a tannic acid-nanocellulose/sulfonated carbon nanotube-reinforced polyvinyl alcohol hydrogel

The operating temperature of hydrogels, especially at low temperatures, is crucial due to their wide applicability in soft robots, sensors, and electronic skin. Hydrogels are often used at room temperature, but their performance may deteriorate at low temperatures. Therefore, it is crucial to develop hydrogels that can be used at low temperatures to expand their range of use. Herein, we have proposed a simple one-pot method to prepare a frost-resistant (−70 °C) and conductive hydrogel consisting of a glycerol (Gly)-water binary solvent. We have added tannic acid (TA)-coated carboxymethylated cellulose nanofibrils (CMCNFs) to poly (vinyl alcohol) (PVA) as a functional filler to improve the hydrogel's mechanical properties. The introduction of sulfonated carbon nanotubes (SCNT) has provided the hydrogel with high conductivity (0.1 S/m), strain sensitivity (gauge factor of 3.76), and cyclic stability (1600 cycles). Due to the strong hydrogen bonding and physical entanglement effects between the components, the hydrogel exhibied excellent tensile properties (297 %), high toughness (0.44 MJ/m3), and a high Young's modulus (1.25 MPa). These characteristics ensure that the hydrogel is well suited for low-temperature environments, health monitoring, and wearable devices.