Mixture Of Glycerol Research Articles

Study of Binary Mixtures of Glycerol with N,N-Dimethylformamide, Ethylene Glycol, and Formamide at 293.15 K

Study of Binary Mixtures of Glycerol with N,N-Dimethylformamide, Ethylene Glycol, and Formamide at 293.15 K

Synthesis of BODIPY-pyrrolo[3,4-b]pyridin-5-ones via Ugi-Zhu/cascade reactions and studies of fluorescence response toward viscosity.

A series of seven new meso-phenyl BODIPY-pyrrolo[3,4-b]pyridin-5-one conjugates were synthesized in one experimental step by using a Sc(III)-catalyzed Ugi-Zhu three-component reaction coupled to a cascade sequence (aza Diels-Alder/N-acylation/aromatization) as post-MCR functionalization process. Further experimental studies were performed behind understanding the fluorescence response toward viscosity. All compounds exhibited a linear response between increasing viscosity (DMSO and glycerol mixtures) and fluorescence intensity. The different substituents also influenced the photophysical properties. Furthermore, in DMSO all compounds exhibited dual emission. Each band is attributed to the pyrrolo[3,4-b]pyridin-5-one and BODIPY moieties, respectively. The electronic structure of all compounds was computed by DFT and TD-DFT calculations, allowing to determine the molecular orbitals involved in the electronic transitions.

Anomalous behaviour of transport properties in a supercooled water–glycerol mixture

Glycerol acts as a natural cryoprotectant by depressing the temperature of ice nucleation and slowing down the dynamics of water mixtures. In this work, we characterise dynamics – diffusion, viscosity and hydrogen bond dynamics – as well as density anomaly and structure of water mixtures with 1%–50% (w/w) glycerol at low temperatures via molecular dynamics simulations using all-atom and coarse-grained models. Simulations reveal distinct violations of the Stokes–Einstein relation in the low-temperature regime for water and glycerol. Deviations are positive for water at all concentrations, and positive for glycerol in very dilute solutions but turning negative in concentrated ones. The all-atom and coarse-grained models reveal an unexpected crossover in the dynamics of the 1% and 10 % (w/w) glycerol at the lowest simulated temperatures. This crossover manifests in the diffusion coefficients of water and glycerol, as well as in the viscosity and lifetime of hydrogen bonds in water. We interpret that the crossover originates on the opposing dependence with glycerol concentration of the two factors controlling the solutions' slow down: the increase in tetrahedrally coordinated water and the dynamics and clustering of the glycerol molecules. We anticipate that this dynamic crossover will also occur for solution of water with other polyols.

Unlocking glycerol Potential: Novel pathway for hydrogen production and Value-Added chemicals

In the global fight against climate change, the bio-based supply chain represents an interesting solution as it offers the potential to produce high-value-added products and bioenergy through the utilization of waste and by-products. In this work, a new route is proposed for the conversion of bio-based glycerol to H2/CO2 and high value-added liquid and solid products. The innovative process used pure or crude glycerol or ethanol-glycerol mixture along with water and sodium metaborate as reagents at 300 °C under discontinuous conditions. The gas stream consists mainly of hydrogen, followed by biogenic CO2 (31–54 %), CO (4–13 %) and CH4 in traces. The presence of water in the tested crude glycerol improved the hydrogen selectivity to 55 %. Characterization of the liquid reaction products revealed the synthesis of products such as 1,2-propanediol, propanoic acid, acetic acid, cyclopentenones and cyclic diglycerol. In the solid phase, an aliphatic hydrocarbon resin with oxygenated carbon along the saturated chain and an aromatic cluster were also characterized by NMR, FTIR and TG analyses. Based on these findings, the global reaction route to the general reaction products was proposed.

Stable and unstable fall motions of plate-like ice crystal analogues

Abstract. The orientation of ice crystals affects their microphysical behaviour, growth, and precipitation. Orientation also affects interaction with electromagnetic radiation, and through this it influences remote sensing signals, in situ observations, and optical effects. Fall behaviours of a variety of 3D-printed plate-like ice crystal analogues in a tank of water–glycerine mixture are observed with multi-view cameras and digitally reconstructed to simulate the falling of ice crystals in the atmosphere. Four main falling regimes were observed: stable, zigzag, transitional, and spiralling. Stable motion is characterised by no resolvable fluctuations in velocity or orientation, with the maximum dimension oriented horizontally. The zigzagging regime is characterised by a back-and-forth swing in a constant vertical plane, corresponding to a time series of inclination angle approximated by a rectified sine wave. In the spiralling regime, analogues consistently incline at an angle between 7 and 28°, depending on particle shape. Transitional behaviour exhibits motion in between spiral and zigzag, similar to that of a falling spherical pendulum. The inclination angles that unstable planar ice crystals make with the horizontal plane are found to have a non-zero mode. This observed behaviour does not fit the commonly used Gaussian model of inclination angle. The typical Reynolds number when oscillations start is strongly dependent on shape: solid hexagonal plates begin to oscillate at Re =237, whereas several dendritic shapes remain stable throughout all experiments, even at Re > 1000. These results should be considered within remote sensing applications wherein the orientation characteristics of ice crystals are used to retrieve their properties.

Innovative Hemp Shive-Based Bio-Composites: Part I: Modification of Potato Starch Binder by Sodium Meta-Silicate and Glycerol

The growing demand for sustainable building materials has boosted research on plant-based composite materials, including hemp shives bound with biodegradable binders. This study investigates the enhancement of potato-starch-based binders with sodium metasilicate and glycerol to produce eco-friendly bio-composites incorporating hemp shives. Potato starch, while renewable, often results in suboptimal mechanical properties and durability in its unmodified form. The addition of sodium metasilicate is known to improve the mechanical strength and thermal stability of starch-based materials, while glycerol acts as a plasticizer, potentially enhancing flexibility and workability. Bio-composites were produced with varying concentrations of sodium metasilicate (0–107% by mass of starch) and glycerol (0–133% by mass of starch), and their properties were evaluated through thermal analysis, density measurements, water absorption tests, compressive strength assessments, and thermal conductivity evaluations. The results demonstrate that sodium metasilicate significantly increases the bulk density, water resistance, and compressive strength of the bio-composites, with enhancements up to 19.3% in density and up to 2.3 times in compressive strength. Glycerol further improves flexibility and workability, though excessive amounts can reduce compressive strength. The combination of sodium metasilicate and glycerol provides optimal performance, achieving the best results with an 80% sodium metasilicate and 33% glycerol mixture by weight of starch. These modified bio-composites offer promising alternatives t2 o conventional building materials with improved mechanical properties and environmental benefits, making them suitable for sustainable construction applications.

Acute effect of the novel cadaver fixation and storage solution -Anatomical-biomechanical-microbiological study

Cadaver education is a golden standard in health sciences. It is aimed to purify the cadavers from microbes by subjecting them to chemicals and to be used for many years by terminating autolysis. As a result of literature searches, a solution consisting of a mixture of borax, nitrite-nitrate, glycerin, alcohol, and thyme oil was created. While seven sheep hearts were placed in this solution, seven were kept in 10% formaldehyde for two months for fixation and storage. At the end of the first ten days, it was observed that the discoloration of the heart in the solution was lower than the formalin fixation. In histological examinations, it was observed that there was no visual difference between the groups and the tissue could be examined at all magnifications. At the end of two months, insignificant microbial growth observed in the solution. While color changes were better than formaldehyde, texture profile analysis values were found to be closer to fresh heart. In histological examinations, in the solution group, although the tissue could be recognized at all magnifications, it was observed that cell nuclei were less stained at x100. It was concluded that this solution can be used mainly in short-term courses.

Modification of Sulfur Cake—Waste from Sulfuric Acid Production

In the production of sulfuric acid, sulfur cake—a waste product of the sulfur purification process—is formed in large quantities, which requires its disposal and use. For its use in composite materials, modification is necessary to convert sulfur into a polymer form. The aim of the study was to develop a method for modifying sulfur cake—a waste product of sulfuric acid production—for its disposal. Available reagents—styrene, glycerol, and oleic acid—were tested as modifiers in the work. The sample compositions consisted of 100% sulfur cake (no. 1) and its mixtures: 97% sulfur cake + 3% styrene (no. 2), 97% sulfur cake + 3% glycerol (no. 3), 97% sulfur cake + 3% oleic acid (no. 4), 95% sulfur cake + 3% styrene, 1% glycerol, and 1% oleic acid (no. 5). Modification of sulfur cake was carried out at a temperature of 140 °C for 30 min. The composition, crystal structure, and thermal properties of the samples of the original and modified sulfur cake were studied using X-ray phase and X-ray structural analyses, IR spectroscopy, differential scanning calorimetry, differential thermal and thermogravimetric analysis. The optimal modifier for sulfur cake was a mixture of styrene, glycerol, and oleic acid, which led to the formation of acetal (polyoxymethylene) and an improvement in the structure due to a decrease in the content of impurities. Modification of sulfur cake with styrene resulted in the appearance of a CAr–S bond band at 571 cm−1, and modification with oleic acid a C–S band in the region of 694 cm−1 in the IR spectra. The results of differential scanning calorimetric analysis showed an increase in the heat of fusion of sulfur by 12.45 J/g in the samples of sulfur cake modified with glycerol and styrene. Modification of sulfur cake with oleic acid and a mixture of reagents resulted in the appearance of a third peak with maxima at 244.2 and 264.0 °C, which demonstrated a significant effect of the indicated additives on the thermal behavior of the sulfur cake. Proposed schemes for modifying sulfur cake with styrene and oleic acid are presented.

Impact of agar–glycerol ratios on the physicochemical properties of biodegradable seaweed films: A compositional study

To develop technology more applicable to industrial settings, this study aimed to produce agar-based bioplastic films using extrusion followed by hot compression. The research examined various amounts of glycerol incorporation as the plasticizer, which also facilitated the flowability of the extrusion process. These variations included agar–glycerol ratios of 75:25, 70:30, 65:35, 60:40, and 55:45 (% w/w). Moreover, the films underwent thorough testing to assess their physical, mechanical, chemical, water sensitivity, surface imaging, and biodegradability properties. The results showed that increasing the amount of glycerol in the agar film matrix generally made the films more sensitive to water, resulting in greater hydrophilicity. This change was primarily owing to the increased presence of hydroxyl groups. It also affected other characteristics, such as enhancing the film's stretchability and thermal stability. Furthermore, a decrease in film density was observed, leading to reduced tensile strength and barrier properties. Moreover, the higher glycerol content improved its surface wettability and the higher agar content accelerated the film's biodegradability rate. Microstructural examination using scanning electron microscopy and chemical analysis (FTIR) revealed a homogeneous mixture of agar and glycerol produced through the extrusion process. These findings demonstrate the potential of extrusion techniques for the large-scale production of agar-based bioplastics.

Development of biodegradable plastic films from cassava starch

Plastic has become part of daily life because it is used in all industrial applications. Although it is beneficial and practical, it is the material that generates the most pollution in ecosystems. Therefore, the main objective of this research is to produce plastic films capable of degrading the environment in a shorter time (bioplastics). For this purpose, different samples were made with cassava starch (pulp or commercial), using amounts in the solution of 4% w/v and 30% w/w of cassava starch and glycerol, respectively, considering variations between the percentages of chitosan. The results showed that it is possible to obtain bioplastic by the casting method with the mixture of cassava starch (pulp or commercial), glycerol, and chitosan. Likewise, thanks to the laboratory tests carried out, was possible to determine that the use of commercial starch to produce biodegradable plastic films significantly favors moisture adsorption, solubility, and biodegradability, compared to starch extracted from cassava by hand, with good statistics validity of the analyzed data.

Automatic characterization of capillary flow profile of liquid samples on μTADs based on capacitance measurement

Capillary flow profile of liquid samples in porous media is closely related to the important properties of liquid samples, including the viscosity and the surface energy. Therefore, capillary flow profile can be used as an index to differentiate liquid samples with different properties. Fast and automatic characterization of capillary flow profile of liquid samples is necessary. In this work, we develop a portable and economical capacitance acquisition system (CASY) to easily obtain the capillary flow profile of liquid samples on microfluidic thread-based analytical devices (μTADs) by measuring the capacitance during the capillary flow. At first, we validate the accuracy of this method by comparing with the traditional method by video analysis in obtaining the capillary flow profiles in μTADs of cotton threads or glass fiber threads. Then we use it to differentiate liquid samples with different viscosity (mixture of water and glycerol). In addition, capillary flow profile on μTADs with chemical valves (chitosan or sucrose) can also be obtained on this device. Lastly, we show the potential of this device in measurement of hematocrit (HCT) of whole blood samples. This device can be used to catalog liquid biological samples with different properties in point-of-care diagnostics in the near future.

Spectroscopic and computational methods in the characterization of deep eutectic solvent, Gallic acid, and Glycerol

Several researchers have shown experimentally that Gallic acid has antioxidant, anti-inflammatory, and anti-aging properties, signifying its value in skin care. Glycerol has properties, such as increasing skin hydration, softening skin, and reducing skin dryness. The present work aims to understand the vibrational and spectroscopic study of the interacting mechanism of Deep Eutectic solvent mixture of Gallic acid and Glycerol. The theoretical analysis is performed using the Density Functional Theory with B3LYP/6-311 + g(d,p) level of theory. The optimized structure and frequency of the monomers and their biomolecular complex are obtained using Gauss view 6.0 and Gaussian16. The vibrational analysis is carried out using Vibrational Energy Distribution Analysis. The Natural Bond Orbital, molecular docking of the Glycerol-Gallic acid complex, and the molecular dynamics simulation of the docked protein-ligand system are carried out to understand the mechanism better. The theoretical and experimental frequencies are found to agree with each other. The Molecular Dynamic simulation analysis predicts that the protein-ligand complexation is relatively stable.

XGBoost algorithm assisted multi-component quantitative analysis with Raman spectroscopy

To improve prediction performance and reduce artifacts in Raman spectra, we developed an eXtreme Gradient Boosting (XGBoost) preprocessing method to preprocess the Raman spectra of glucose, glycerol and ethanol mixtures. To ensure the robustness and reliability of the XGBoost preprocessing method, an X-LR model (which combined XGBoost preprocessing and a linear regression (LR) model) and a X-MLP model (which combined XGBoost preprocessing and a multilayer perceptron (MLP) model) were developed. These two models were used to quantitatively analyze the concentrations of glucose, glycerol and ethanol in the Raman spectra of mixed solutions. The proportion map of hyperparameters was firstly used to narrow down the search range of hyperparameters in the X-LR and the X-MLP models. Then the correlation coefficients (R2), root mean square of calibration (RMSEC), and root mean square error of prediction (RMSEP) were used to evaluate the models’ performance. Experimental results indicated that the XGBoost preprocessing method achieved higher accuracy and generalization capability, with better performance than those of other preprocessing methods for both LR and MLP models.

Transparency-changing elastomers by controlling of the refractive index of liquid inclusions

Complex materials that change their optical properties in response to changes in environmental conditions can find applications in displays, smart windows, and optical sensors. Here a class of biphasic composites with stimuli-adaptive optical transmittance is introduced. The biphasic composites comprise aqueous droplets (a mixture of water, glycerol, and surfactant) embedded in an elastomeric matrix. The biphasic composites are tuned to be optically transparent through a careful match of the refractive indices between the aqueous droplets and the elastomeric matrix. We demonstrate that stimuli (e.g., salinity and temperature change) can trigger variations in the optical transmittance of the biphasic composite. The introduction of such transparency-changing soft matter with liquid inclusions offers a novel approach to designing advanced optical devices, optical sensors, and metamaterials.

Study on preparation and properties of antifreeze compound road dust suppressant

Open-pit mine pavement dust dries and breaks easily. As such, a composite pavement dust suppressant with good wettability, moisturizing, coagulation, and antifreezing properties in winter was investigated. Monomer screening and orthogonal experiments were conducted, using evaporation rate, permeability rate, viscosity, and freezing point as evaluation indexes. Consequently, a dust suppressant solution is a mixture of glycerol (GLY), sodium dodecylbenzene sulfonate (SDBS), polyacrylamide (PAM), compound propylene glycol (PG), and potassium acetate (PA). The characteristics of the dust suppressant and its interaction mechanism with road dust were measured and analyzed. The results showed that the optimal ratio of the antifreeze-type composite dust suppressant is 3%GLY, 0.30%SDBS, 0.07% PAM, and 50%PG + 10%PA; the contact angle is 27.62°, which can effectively wet coal dust. Moreover, it easily forms hydrogen bonds with water molecules to release free -OH, which increases the oxygen-containing functional groups in the dust. The maximum viscosity is 25.4 mPa·s, and the hydrophobic groups adsorbed on the surface of the dust can condense and agglomerate the dust to form large particles, and effectively inhibit the occurrence of dust. It freezes at − 34.2 ℃, resists a temperature of − 30 ℃ without freezing, and improves dust suppression efficiency and antifreezing effect in cold areas.

Coupled CFD-DEM simulation of pin-type wet stirred media mills using immersed boundary approach and hydrodynamic lubrication force

Qualitative description of stressing energies between grinding beads/media in wet stirred media mills at different operation settings could provide a comprehensive understanding of the process parameter influence. In the current work, a modeling approach for wet stirred media mills is described, employing a coupled CFD-DEM framework. This study employs an immersed boundary methodology to emulate the pin-type stirrer rotation in CFD and utilizes a hydrodynamic lubrication force to model the squeezing out and sucking in of fluid between two grinding bead surfaces. The results indicate the influence of process parameters such as the stirrer rotation speed, bead diameter, and bead filling degree. Key findings include the necessity of coupled CFD-DEM with lubrication (i.e., comparison of results from DEM, and coupled CFD-DEM simulations). Dependence of system dynamics on the fluid properties is numerically analyzed using the properties of water–glycerol mixtures.

Employing a mixture of fine-particle PKS, glycerol, and citric acid as an eco-friendly binder for plywood production from rubberwood (Hevea brasiliensis) veneer

Biomass-based adhesives, which are environmentally friendly and sustainable materials enabling low formaldehyde wood composites, have garnered interest. Therefore, palm kernel shells (PKS), available as industrial agricultural residue and rich in lignin, are mixed in form of fine particles with glycerol and citric acid, and tested as a candidate for binder in plywood production. The study focused on examining the effects of two factors: the quantity of adhesive used and the pressing temperature. Glycerol and citric acid are low-cost non-toxic chemicals that activate the functional groups and induce changes in the PKS component during hot pressing. Consequently, the mixtures with PKS as fine particles could cross-link with rubberwood veneer, forming a plywood panel with shear strength and bending strength that meet the requirements outlined in ISO 12466-2: part 2, and in Thai industrial standard (TIS 178-2549) for indoor use. The properties of plywood were primarily influenced by the pressing temperature rather than by the quantity of adhesive. Specifically, the temperatures 180 °C and 200 °C enhanced the extent to which the molten binder penetrated the rubberwood surface, consequently improving the mechanical properties and water resistance of the bonding.

Nanocomposite hydrogel for skin motion sensing – An antifreezing, nanoreinforced hydrogel with decorated AuNP as a multicrosslinker

In this study, we present a nanocomposite hydrogel designed for skin motion sensing. The hydrogel is based on poly(acrylamide) crosslinked with gold nanoparticles covalently bound to the polymer matrix, yielding a robust, highly elastic and conductive material. The choice of amino acid derivative – N,N’-diacryloylcystine salt (BISS) – as a crosslinker allows for the introduction of gold nanoparticles, due to the presence of sulfide groups in its structure. During the nanoparticle modification process, covalent bonds between gold and sulfur atoms are formed as the disulfide bond is cleaved. In result of this self-assembly process, a multifunctional Au–BISS crosslinker is formed, enhancing the material’s mechanical properties and introducing electrical conductivity. To confer anti-freezing properties and limit water evaporation, a binary mixture of water and glycerol was used. The resultant hydrogel exhibits high elasticity, strain sensitivity across a wide strain range and various types of deformation (elongation, bending, compression) with exceptional response time (120 ms) and recovery time (90 ms). The material’s cold-resistance, resilience, and conductivity make it well-suited for real-time monitoring of joint movements and speech recognition, with potential applications in electronic skin and healthcare monitoring devices.

Terahertz Sensing of L-Valine and L-Phenylalanine Solutions.

To detect and differentiate two essential amino acids (L-Valine and L-Phenylalanine) in the human body, a novel asymmetrically folded dual-aperture metal ring terahertz metasurface sensor was designed. A solvent mixture of water and glycerol with a volume ratio of 2:8 was proposed to reduce the absorption of terahertz waves by reducing the water content. A sample chamber with a controlled liquid thickness of 15 μm was fabricated. And a terahertz time-domain spectroscopy (THz-TDS) system, which is capable of horizontally positioning the samples, was assembled. The results of the sensing test revealed that as the concentration of valine solution varied from 0 to 20 mmol/L, the sensing resonance peak shifted from 1.39 THz to 1.58 THz with a concentration sensitivity of 9.98 GHz/mmol∗L-1. The resonance peak shift phenomenon in phenylalanine solution was less apparent. It is assumed that the coupling enhancement between the absorption peak position of solutes in the solution and the sensing peak position amplified the terahertz localized electric field resonance, which resulted in the increase in frequency shift. Therefore, it could be shown that the sensor has capabilities in performing the marker sensing detection of L-Valine.

Isolation of taro peel cellulose nanofibers and its application in improving functional properties of taro starch nanocomposites films

The current work focuses on developing nanocomposite films using taro starch and cellulose nanofibers extracted from the root's peel. Films were prepared using mixtures of starch, cellulose nanofibers (0 %, 5 %, 10 %, and 15 % w/w), glycerol, and water. Results showed that the addition of cellulose nanofibers increased film thickness, opacity, UV-light barrier capacity, and water swelling percentage. All films showed a typical B-type X-ray diffraction pattern characteristic of semicrystalline materials. FTIR analysis confirmed chemical interactions between the starch chains and the nanofibers, which probably interact through hydrogen bonds. Nanocomposite films exhibited increased tensile strength and reduced strain at break compared to control materials. Films with cellulose nanofibers showed an increase in Young's modulus compared to control ones, with no differences observed between films with cellulose nanofibers at 10 % and 15 %. Furthermore, films with cellulose nanofibers at 5 % and 10 % exhibited lower water vapor permeability than control samples, while those with cellulose nanofibers at 15 % showed an increase in this parameter compared to other materials. These results suggest that incorporating taro cellulose nanofibers is a promising alternative for obtaining taro starch nanocomposites films with improved properties.