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The integration of digital technology into everyday life has been a long-standing human pursuit. Currently, wearable electronic skins emerged as a transformative innovation have been widely used in human motion monitoring, healthcare, and artificial intelligence. To explore an interdisciplinary talent cultivation model that merges chemistry, chemical engineering, and biomedical sciences, gellan gum/polyacrylamide dual network hydrogel was fabricated and applied as flexible sensor to monitor human movement and physiological signals. The experiment combines the published research work in our group with undergraduate teaching experiments, and introduces the E-skin to students from preparation method to its practical application, stimulating students' interests in learning and innovation. [ABSTRACT FROM AUTHOR]

Cold-adapted species are able to generate cryoprotective proteins and glycoproteins to prevent freezing damage. The [→4)- β -D-Man p -(1→4)- β -D-Xyl p -(1→] n xylomannan from the Alaska beetle Upis ceramboides was disclosed by Walters and co-workers in 2009 as the first glycan-based antifreeze agent, which was later reported to be found in diverse taxa. Here, we report the rapid synthesis of four types of xylomannans, including the proposed antifreeze xylomannan up to a 64-mer (Type I), the regioisomeric [→3)- β -D-Man p -(1→4)- β -D-Xyl p -(1→] n 16-mer (Type II), the diastereomeric [→4)- β -L-Man p -(1→4)- β -D-Xyl p -(1→] n 16-mer (Type III) and the block-wise [→4)- β -D-Man p -(1→] m [→4)- β -D-Xyl p -(1→] n 32-mer (Type IV), by employing a strategic iterative exponential glycan growth (IEGG) process. The nuclear magnetic resonance spectral data of the alleged natural xylomannan are in accordance only to those of the block-wise Type IV glycan and none of these synthetic xylomannans has been found to be capable of inducing thermal hysteresis. These results disprove the previous reports about the natural occurrence of antifreeze xylomannans. [ABSTRACT FROM AUTHOR]

Zwitterionic hydrogels have emerged as a promising option due to their remarkable ionic conductivity. However, these hydrogels often suffer from poor mechanical properties due to their super hydrophilicity. Herein, we propose the use of a rigid aryl imidazolium monomer (AIm) for crosslinking with poly(vinyl alcohol) (PVA) to create a unique zwitterion hydrogel. Chlorosulfonic acid acts as an agent to introduce anionic groups, facilitating the transfer of Zn2⁺ ions in zwitterionic hydrogel. We achieve extraordinary mechanical properties by incorporating an optimal amount of AIm into the PZW2 hydrogel (tensile stress 0.9 MPa and stretch 1400 %). Above all, the PZW2 hydrogel exhibits remarkable resistance to freezing, remaining unfrozen even at up to −80 °C. This anti-freezing property is attributed to the cation-dipole interactions and the presence of ZnCl2, effectively preventing water from freezing within the hydrogel structure. Furthermore, the PZW2 hydrogel demonstrates a high ionic conductivity of 4.34 S m−1 at room temperature. This can be attributed to the presence of anionic and cationic charges within the PZW2 hydrogel, which facilitates the transfer of ions through a hopping mechanism. The PZW2 hydrogel demonstrates better performance compared to most antifreeze conductive hydrogels. At −20 °C, it achieves an impressive ionic conductivity of 2.73 S m−1 and retains outstanding mechanical characteristics with a stretchability of 1000 %. Ultimately, the PZW2 hydrogel demonstrates a sensitive response performance with a gauge factor of 1.59, making it highly suitable for potential sensor applications.

Abstract Recently, significant progress has been made regarding conductive hydrogels‐based flexible sensors in health detection, electronic skin, soft robots, etc. However, the requirement of bonding with the substrate through the adhesive tape, brokenness sensitivity, and degradation of performance under low‐temperature environments, strongly limit the wide applications of conductive hydrogels in flexible sensors. To solve these problems, this study introduces lithium chloride (LiCl) into poly(vinyl alcohol)/tannic acid/polyacrylamide (PVA/TA/PAM) hydrogels to endow the hydrogels with excellent conductivity and antifreeze properties. In addition, the addition of tannic acid (TA) and zwitterionic 3‐[Dimethyl‐[2‐(2‐methylprop‐2‐enoyloxy)ethyl]azaniumyl]propane‐1‐sulfonate (SBMA) enables the hydrogel to have good self‐healing performance (after 72 h of healing at 20 °C, the healing efficiency of fracture stress is 24%, and the healing efficiency of fracture strain is 52%) and adhesion (the adhesion strength to paper at 20 °C is 14.12 KPa). The sensors based on PVA/TA/PAM composite hydrogels exhibit good sensibility, stability, and durability, and can respond quickly to human joint activities (finger bending, wrist bending, arm bending, and leg bending). Therefore, the multifunctional PVA/TA/PAM composite hydrogel demonstrates significant potential for applications in flexible strain sensors under extreme environments.

Freeze-thaw cycles significantly impact construction by altering soil properties and stability, which can lead to delays and increased costs. While soil-stabilizing additives are vital for addressing these issues, stabilized soils remain susceptible to volume changes and structural alterations, ultimately reducing their strength after repeated freeze-thaw cycles. This study aims to introduce a different approach by employing magnesium chloride (MgCl2) as an antifreeze and soil stabilizer additive to enhance the freeze-thaw resilience of clay soils. We investigated the efficiency of MgCl2 solutions at concentrations of 4%, 9%, and 14% on soil by conducting tests such as Atterberg limits, standard proctor compaction, unconfined compression, and freeze-thaw cycles under extreme cold conditions (−10 °C and −20 °C), alongside microstructural analysis with SEM, XRD, and FTIR. The results showed that MgCl2 reduces the soil's liquid limit and plasticity index while enhancing its compressive strength and durability. Specifically, soil treated with a 14% MgCl2 solution maintained its volume and strength at −20 °C, with similar positive outcomes observed for samples treated with 14% and 9% MgCl2 solutions at −10 °C. This underlines MgCl2's potential to enhance soil stability during initial stabilization and, most importantly, preserve it under cyclic freeze-thaw stresses, offering a solution to improve construction practices in cold environments. [ABSTRACT FROM AUTHOR]

[Display omitted] Improving mechanical strength and frost-resistance is an important research direction in the field of hydrogel materials. Herein, using bacterial nanocellulose (BC) as a reinforcing agent and polyvinyl alcohol (PVA) as a polymer matrix, a frost-resistant organohydrogel was constructed via the freezing-thawing method in a new binary solvent system of N, N -dimethylformamide and water (DMF-H 2 O), which was designed according to the Hansen Solubility Parameter. Owing to the solvent-induced crystallization effect that led to the enhanced 3D hydrogen bonding network during the freezing-thawing process, the optimal organohydrogel achieved excellent mechanical properties with the tensile strength of 2,974 kPa and the stretchability of 277 % at room temperature, respectively. In the visible light range, the organohydrogel demonstrated high transmittance. Moreover, the presence of a DMF-H 2 O binary solvent endows it with frost-resistance, retaining the tensile strength of 508 kPa and a stretchability of 190 % even at −70 °C, respectively. This kind of transparent, frost-resistant organohydrogel has potential uses in harsh settings due to its great mechanical strength. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Antifreeze peptides have become effective antifreeze agents for frozen products, but their low quantity of active ingredients and high cost limit large-scale application. This study used the glycosylation of fish collagen peptides with glucosamine hydrochloride catalyzed by transglutaminase to obtain a transglutaminase-catalyzed glycosylation product (TGP) and investigate its antifreeze effect on tilapia. Compared with the blank group, the freshness (pH value of 6.31, TVB-N value of 21.7 mg/100 g, whiteness of 46.28), textural properties (especially hardness and elasticity), and rheological properties of the TGP groups were significantly improved. In addition, the protein structures of the samples were investigated using UV absorption and fluorescence spectroscopy. The results showed that the tertiary structure of the TGP groups changed to form a dense polymer. Therefore, this approach can reduce the denaturation and decomposition of muscle fibers and proteins in fish meat more effectively and has a better protective effect on muscle structure and protein aggregation, improving the stability of fish meat. This study reveals an innovative method for generating antifreeze peptides by enzymatic glycosylation, and glycosylated fish collagen peptide products can be used as new and effective green antifreeze agents in frozen foods. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purity of crude glycerol, a by-product of biodiesel production, may be as low as 50%. Thus, it has relatively low economic value without previously applying adequate physical purification or chemical conversion processes. A solid-state sulfated acid photocatalyst, TiO2/SO42− was prepared in this study to catalyze the chemical conversion of bioglycerol with acetic acid to produce an antifreeze of glycerine acetate to improve the low-temperature fluidity of liquid fuel. The experimental results show that similar X-ray intensity structures appeared between the catalysts of TiO2/SO42− and SO42−. An infrared spectra analysis using a Fourier transform infrared (FTIR) spectrometer confirmed the successful sintering of SO42− and ligating with TiO2 for preparing TiO2/SO42−. The effects of the photocatalyst were further excited by the irradiation of ultraviolet light. The highest weight percentage of glycerine acetate was obtained under a reaction time and reaction temperature of 10 h and 120 °C, respectively. In addition, it was observed that the glycerol conversion ratio reached 98.65% and the triacylglycerols compound amounted to 40.41 wt.% when the reacting molar ratio was 8. Moreover, the freezing point of the product mixture of glycerine acetate under the same molar ratio reached as low as −46.36 °C; the lowest among the products made using various molar ratios of acetic acid/glycerol. The UV light irradiation rendered higher triacylglycerols and diacylglycerols with lower diacylglycerol formation ratios than those without light irradiation. [ABSTRACT FROM AUTHOR]

The operation time of HVAC systems in industry and construction engineering is counted in decades. Corrosion protection of these systems is crucial for their long-term and failure-free operation. In the case of working mediums based on glycols, corrosion protection is provided by anti-corrosion additives, which are the component of antifreeze. The defence mechanism consists in the interaction of these additives with metal surfaces, with whom they contact by creating durable and efficient layers separating their surfaces from aggressive environmental factors. Observation of the structure of protective layers and corrosion micro changes was possible due to the application of microscopic imaging. The main building material in heat exchangers is copper. Studies have shown that the dilution of antifreeze may result in the formation of insufficiently clear protective layers on the copper surface, which may intensify the negative effects of fluids on copper elements of infrastructure HVAC systems. [ABSTRACT FROM AUTHOR]

This article proposes a better alternative method to prepare CNT antifreeze nanofluid in EG/water by modifying the conventional method that requires long hours of sonication. Sonicating a sample for long hours is time and energy consuming and may deform the structure of CNT. In the modified method, the nanofluid preparation was carried out by dispersion of CNT in EG via sonication followed by adding water and again sonication. The study shows that nanofluid could be prepared in less sonication time of 1.5 h compared to the 5 h required in the conventional method. FTIR spectroscopy revealed that interaction of EG with CNT occurs via trans conformation resulting in greater stabilization and better interaction of nanofluid prepared by this method (85 days) as compared to nanofluid prepared by the conventional method (50 days). The nanofluid prepared by this method has better physical–chemical properties compared to nanofluid prepared by the conventional method. The nanofluid prepared by this method showed higher stability and better physical–chemical properties at a lower sonication time. Hence it is a more effective and cost efficient technique for preparing CNT (EG/water) nanofluid. [ABSTRACT FROM AUTHOR]

The study is dedicated to the consideration of lower alkyl ethers of glycerol as potential components of low-melting technical fluids (e.g., heat transfer fluids, hydraulic fluids, aircraft de-icing fluids, etc.). Four isomeric mixtures of glycerol ethers (GMME—monomethyl; GDME—dimethyl; GMEE—monoethyl; GDEE—diethyl) were synthesized from epichlorohydrin and methanol/ethanol in the presence of sodium and subjected to detailed characterization as pure compounds and as aqueous solutions (30–90 vol%). The temperature and concentration dependencies of density, viscosity, cloud point, boiling range, specific heat capacity, thermal conductivity, and rubber swelling were obtained. On the basis of the data obtained, a comparison was made between the aqueous solutions of glycerol ethers and of other common bases for low-melting liquids (glycerol, ethylene glycol, and propylene glycol). Pure glycerol ethers could potentially be used as technical fluids in a very wide temperature range—from −114 to 150 °C. It was further demonstrated that in low temperature applications (e.g., in low-temperature chiller systems) the glycerol-ether-based aqueous heat transfer fluids could provide enhanced efficiency when compared to the glycerol- or propylene-glycol-based ones due to their lower viscosities and favorable environmental properties. [ABSTRACT FROM AUTHOR]

Determining the glycol type and concentration of an engine coolant is a useful analytical test for in-service testing laboratories to both identify the coolant type and determine whether the coolant is fit for its intended purpose. Too much glycol can result in poor heat transfer within the engine whereas too little glycol can increase the freeze point of the coolant. As such repeat testing over the lifespan of the coolant is requir ed to avoid potential problems and ensure the overall health of the cooling system. This paper details a GC method to rapidly separate ethylene and propylene glycol in under five minutes and determine the concentration of these glycols in percentage. Two preparation methods are detailed to demonstrate a simple 'dilute & shoot' preparation by diluting in deionised water (10-fold dilution) or isopropanol (100-fold dilution). [ABSTRACT FROM AUTHOR]

Freeze-thaw cycles significantly impact construction by altering soil properties and stability, which can lead to delays and increased costs. While soil-stabilizing additives are vital for addressing these issues, stabilized soils remain susceptible to volume changes and structural alterations, ultimately reducing their strength after repeated freeze-thaw cycles. This study aims to introduce a different approach by employing magnesium chloride (MgCl2) as an antifreeze and soil stabilizer additive to enhance the freeze-thaw resilience of clay soils. We investigated the efficiency of MgCl2 solutions at concentrations of 4%, 9%, and 14% on soil by conducting tests such as Atterberg limits, standard proctor compaction, unconfined compression, and freeze-thaw cycles under extreme cold conditions (−10 °C and −20 °C), alongside microstructural analysis with SEM, XRD, and FTIR. The results showed that MgCl2 reduces the soil’s liquid limit and plasticity index while enhancing its compressive strength and durability. Specifically, soil treated with a 14% MgCl2 solution maintained its volume and strength at −20 °C, with similar positive outcomes observed for samples treated with 14% and 9% MgCl2 solutions at −10 °C. This underlines MgCl2’s potential to enhance soil stability during initial stabilization and, most importantly, preserve it under cyclic freeze-thaw stresses, offering a solution to improve construction practices in cold environments.

Antifreeze peptides have become effective antifreeze agents for frozen products, but their low quantity of active ingredients and high cost limit large-scale application. This study used the glycosylation of fish collagen peptides with glucosamine hydrochloride catalyzed by transglutaminase to obtain a transglutaminase-catalyzed glycosylation product (TGP) and investigate its antifreeze effect on tilapia. Compared with the blank group, the freshness (pH value of 6.31, TVB-N value of 21.7 mg/100 g, whiteness of 46.28), textural properties (especially hardness and elasticity), and rheological properties of the TGP groups were significantly improved. In addition, the protein structures of the samples were investigated using UV absorption and fluorescence spectroscopy. The results showed that the tertiary structure of the TGP groups changed to form a dense polymer. Therefore, this approach can reduce the denaturation and decomposition of muscle fibers and proteins in fish meat more effectively and has a better protective effect on muscle structure and protein aggregation, improving the stability of fish meat. This study reveals an innovative method for generating antifreeze peptides by enzymatic glycosylation, and glycosylated fish collagen peptide products can be used as new and effective green antifreeze agents in frozen foods.

Herein, the chemical compatibility of the hydrogel electrolyte in highly alkaline pH was evaluated. Through simple experiments, we demonstrated that the frequently used polymer compound, acrylamide, is not stable at a high pH. The addition of glycerol as a cryoprotectant in highly alkaline hydrogels was also problematic due to the possible base‐initiated decomposition of glycerol to polyglycerols. Hence, a quick and simple one‐pot synthesis of highly alkaline potassium poly(acrylate) hydrogel with 1 vol % glycerol was proposed. The ionic conductivities of the hydrogel are 46.48 mS/cm and 8.67 mS/cm at 22 and −23 °C, respectively. One important benefit from the addition of the cryoprotectant is that the hydrogel sustained its mechanical features at temperatures as low as −80 °C. We also reported here for the first time the diffusion coefficients (D at ∼10−8 cm2/s), ionic mobilities (μ at ∼10−7 cm2/Vs), and ion density (n at ∼10−7 cm−3) of the hydrogel electrolyte used in flexible alkaline batteries. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dehydrins exist widely in plants and play an important role in abiotic stress resistance. Two low-temperature-induced dehydrin-like genes, PmCAP and LpCAP, from the pine species Pseudotsuga menziesii and Larix principis-rupprechtii Mayr were cloned and found to contain 576 bp and 687 bp, encoding 191 and 228 amino acids, respectively. Both genes were individually assembled into prokaryotic expression vectors and transferred into E. coli cells. When transgenic stains were cultured at −5 °C, the lethal time 50% (LT50) was 50 h and 54 h for PmCAP and LpCAP, respectively, compared with 32 h for the control. When cultured at −20 °C, the LT50 was 38 h, 41 h, and 25 h for PmCAP, LpCAP, and the control. Thermal hysteresis (TH) testing of PmCAP and LpCAP proteins revealed TH values of 0.27 °C and 0.72 °C, respectively, relative to 0.05 °C for the BSA control. These results indicate that the two pine dehydrin proteins have antifreeze characteristics and that their antifreeze levels were well in relation to the environmental conditions of pine growth (Larix principis-rupprechtii Mayr mostly grows in cold and high-altitude zones, while Pseudotsuga menziesii grows in temperate and low-altitude zones). LpCAP, especially, could be a better gene resource for the molecular breeding of plant cold resistance. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Paraffin-based phase change materials (PPCMs) have been recognized as a potential tool to regulate soil temperature and reduce the freeze–thaw impact on soil. However, as a new filling material for geotechnical structures, such as dam core walls, the engineering applicability of PPCM-mixed soil (PS) needs to be further studied. In this paper, the influences of PPCM on the soil engineering properties (i.e., compaction characteristics, consolidation properties, mechanical behaviors, and permeability) and the PPCM leakage behavior were studied through a series of laboratory experiments. The results showed that the addition of PPCM results in an obvious decrease in the maximum dry density and optimum water content, a slight change in the compression coefficient, a significant reduction of the plasticity and cohesion, and an enhancement of the friction angle and impermeability. In addition, the PPCM in PS specimens will leak under the constant hydraulic gradient or vacuum saturation, and the leaked mass is positively related to the initial PPCM content. The PS specimens after 64-day seepage will still have a good impermeability. This paper is an important prerequisite for the practical applications of PS and provides a basis for its performance improvement. [ABSTRACT FROM AUTHOR]

Alginate organohydrogels prepared in water/alcohol mixtures play an important role in electronic and superconductor applications in low-temperature environments. The study deals with the preparation of Ca-alginate organohydrogels and the analysis of their equilibrium swelling and mechanical properties at sub-zero temperatures. It is shown that the equilibrium degree of swelling at room temperature is noticeably affected by the concentration of co-solvents (methanol, ethanol, and 2-propanol) in the mixtures and the number of carbon atoms in the co-solvent molecules. Mechanical properties are studied in small-amplitude oscillatory tests. The data are fitted with a model that involves three material parameters. The influence of temperature is investigated in temperature-sweep oscillatory tests under a cooling-heating program, where a noticeable difference is observed between the storage and loss moduli under cooling and heating (the hysteresis curves). The hysteresis areas are affected by the cooling/heating rate and the number of carbon atoms in the co-solvents. [ABSTRACT FROM AUTHOR]

A multifunctional hydrogel (C‐ASI‐G) was prepared through a simple acid–base neutralization method. Due to the large number of electrostatic cross‐linked network in the hydrogel and the reversible network, the hydrogel showed good mechanical properties (stress is 495 kPa, strain is 772%) and excellent self‐healing performance (self‐healing efficiency is over 95%). In addition, by adding glycerin to the dispersion medium, hydrogel retain water for a long time and remain flexible at low temperature. The hydrogel contains an ionizable polymer electrolyte, sodium polystyrene sulfonate, so it has outstanding electrical conductivity (0.36 s/m). The hydrogel can be used in general strain sensing and temperature sensing, its conductivity changes with temperature. The temperature and conductivity of the hydrogel were simulated as function, the environmental temperature of the hydrogel could be calculated by the conductivity of the hydrogel, and the error was less than 0.45°C. Because hydrogel can sense stress and temperature stimuli through the change of electrical signals, it will exhibit broad application prospect in the field of bionic intelligent robots. [ABSTRACT FROM AUTHOR]

Antifreeze glycoprotein (AFGP), which inhibits the freezing of water, is highly O‐glycosylated with a disaccharide, d‐Galβ1‐3‐d‐GalNAcα (GalGalNAc). To elucidate the function of the sugar residues for antifreeze activity at the molecular level, we conducted a total chemical synthesis of partially sugar deleted AFGP derivatives, and unnatural forms of AFGPs incorporating glucose (Glc)‐type sugars instead of galactose (Gal)‐type sugars. These elaborated AFGP derivatives demonstrated that the stereochemistry of each sugar residue on AFGPs precisely correlates with the antifreeze activity. A hydrogen–deuterium exchange experiment using synthetic AFGPs revealed a different dynamic behavior of water around sugar residues depending on the sugar structures. These results indicate that sugar residues on AFGP form a unique dynamic water phase that disturbs the absorbance of water molecules onto the ice surface, thereby inhibiting freezing. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work aimed to investigate the effects of pre-freezing injection of l-arginine and l-lysine on the processing performances of porcine Longissimus lumborum muscles. Two kinds of emulsion sausages were prepared from the porcine meat with pre-freezing and post-thawing injection, respectively; and their physicochemical properties were compared. The results showed that the former had significantly higher emulsion stability (lower cooking loss, total expressible fluid and expressible fat), higher texture (hardness, gumminess, cohesiveness and chewiness), and homogeneous microstructure (smaller, more uniform fat/oil droplets and more compact gel network) than the latter. Besides, the pre-freezing injection of l-arginine and l-lysine was more effective in increasing the storage modulus of meat batters, and delaying protein oxidation (lower carbonyl content and higher total sulfhydryl group) of emulsion sausage than the post-thawing injection. Summarily, the pre-freezing injection of l-arginine or l-lysine effectively alleviated the deterioration of the processing performance of porcine muscle during frozen storage. [ABSTRACT FROM AUTHOR]

The article addressed the heat exchange efficiency of an antifreeze flow, used as the working substance in a refrigeration system and filled with a magnetostrictive intermetallic alloy. A dynamic two-dimensional gradient magnetic field was employed as a propulsion source for the magnetostrictive coolant. The regulation and control of the volume flow rate of the coolant were achieved by inducing the dynamic magnetic field, which influenced the orientation and size of the scale-shaped particles dispersed within the coolant. Replacing conventional pumps with magnetic field-based propulsion systems for the circulation of antifreeze in heat-exchange systems offers a reduction in energy consumption in technological systems. [ABSTRACT FROM AUTHOR]

As the most potent ice recrystallization inhibitors, antifreeze glycoproteins (AFGPs) have been extensively studied since their discovery. However, the molecular mechanism of how they inhibit ice growth remains controversial—notably, which group directly contributes to the binding of AFGPs to ice is hotly debated. Here, we use molecular dynamics simulations to investigate the atomistic details of the binding of AFGP8 to ice. We show that the binding of AFGP8 to ice can be divided into three cases: backbone dominant binding (BDB), disaccharide dominant binding (DDB) and weak binding (WB). Hydrogen-bonding and hydrophobic groups contribute equally to the binding of AFGP8 to ice and synergistically promote the binding. The –CH3 groups promote the contacting of AFGP8 to ice via hydrophobic effect, and the hydrogen-bonding groups anchor AFGP8 to ice surfaces through direct hydrogen bonding with ice. Specially, we verify that the -CONH- groups anchor the backbone of AFGP8 to ice by forming hydrogen bonds with ice surfaces while the –OH groups not only anchor the disaccharide to ice but also slow down the dynamics of the surrounding water. In addition, we reveal that both the backbone and the disaccharide can bind to ice surfaces while the latter is more flexible, which also perturbs the hydrogen bond network of potential ice-like water molecules by swaying in the solution to further enhance its antifreeze activity. This work provides the atomistic details of the ice growth inhibition mechanism of AFGP8, which is helpful for the design of high-efficacy cryoprotectants. [ABSTRACT FROM AUTHOR]

Adsorption chillers can avoid two types of greenhouse gas emissions from conventional cooling technologies: energy‐related emissions by utilizing waste heat and refrigerant leakage‐related emissions by employing the natural refrigerant water. However, water restricts the minimal cooling temperature to its freezing point. To overcome this limitation, herein, a boiling antifreeze in adsorption chillers is proposed. For this purpose, a databank of over 12 000 molecules for suitable antifreezes is screened and ethanol is derived as the best candidate. Employing ethanol as antifreeze, the experimental feasibility in a lab‐scale adsorption chiller is demonstrated: ethanol can prevent freezing at a cooling temperature of –5 °C and, thus, extend the operating range of the adsorption chiller. Thereby, the favorable properties of water can be partially retained. Furthermore, water–ethanol mixtures to pure water at a cooling temperature of 10 °C are compared: maximal coefficient of performance (COP) and specific cooling power (SCP) decrease by 45% and 42%, respectively, when 14 mol% ethanol is used instead of pure water. Herein, the influence of ethanol on the adsorbed mass and heat transfer during evaporation are crucial. In summary, boiling antifreezes can extend the operating range of water‐based adsorption chillers below 0 °C. [ABSTRACT FROM AUTHOR]

Abstract Herein, the chemical compatibility of the hydrogel electrolyte in highly alkaline pH was evaluated. Through simple experiments, we demonstrated that the frequently used polymer compound, acrylamide, is not stable at a high pH. The addition of glycerol as a cryoprotectant in highly alkaline hydrogels was also problematic due to the possible base‐initiated decomposition of glycerol to polyglycerols. Hence, a quick and simple one‐pot synthesis of highly alkaline potassium poly(acrylate) hydrogel with 1 vol % glycerol was proposed. The ionic conductivities of the hydrogel are 46.48 mS/cm and 8.67 mS/cm at 22 and −23 °C, respectively. One important benefit from the addition of the cryoprotectant is that the hydrogel sustained its mechanical features at temperatures as low as −80 °C. We also reported here for the first time the diffusion coefficients (D at ∼10−8 cm2/s), ionic mobilities (μ at ∼10−7 cm2/Vs), and ion density (n at ∼10−7 cm−3) of the hydrogel electrolyte used in flexible alkaline batteries.

This article proposes a better alternative method to prepare CNT antifreeze nanofluid in EG/water by modifying the conventional method that requires long hours of sonication. Sonicating a sample for long hours is time and energy consuming and may deform the structure of CNT. In the modified method, the nanofluid preparation was carried out by dispersion of CNT in EG via sonication followed by adding water and again sonication. The study shows that nanofluid could be prepared in less sonication time of 1.5 h compared to the 5 h required in the conventional method. FTIR spectroscopy revealed that interaction of EG with CNT occurs via trans conformation resulting in greater stabilization and better interaction of nanofluid prepared by this method (85 days) as compared to nanofluid prepared by the conventional method (50 days). The nanofluid prepared by this method has better physical–chemical properties compared to nanofluid prepared by the conventional method. The nanofluid prepared by this method showed higher stability and better physical–chemical properties at a lower sonication time. Hence it is a more effective and cost efficient technique for preparing CNT (EG/water) nanofluid.

Objective: The study aimed to improve the storage quality of frozen cooked crawfish tail meat. Methods: Crawfish tail meat were immersed in different proportions of complex phosphate, trehalose and sorbitol antifreeze agents. The thawing loss rate, water content and distribution, water retention, salt-soluble protein, total thiol content, texture properties of crawfish tail meat after freeze-thawed were measured, and the microstructure changes were observed to evaluate the effect of each antifreeze agent. The antifreeze agent with better effect was selected as horizontal factor to design orthogonal experiment, so as to optimize the appropriate recipe of antifreeze agents. Results: 1.5% complex phosphate, 8% trehalose or 10% sorbitol had better cryoprotective effect; The compound antifreeze agent group （1% compound phosphate +6% trehalose +6% sorbitol） had the best cryoprotective effect, and the thawing loss rate was 9.97% under this condition, which was significantly lower than that of the single antifreeze agent group （15.95%, 17.44%, 16.78%）.The combined antifreeze agent group could significantly improve the binding ability of shrimp meat with water and inhibit the damage of ice crystals to muscle tissue during the freeze-thaw process. Conclusion: The combination of antifreeze agents （1% compound phosphate +6% trehalose +6% sorbitol） could effectively improve the cryoprotective ability of cooked crayfish tail meat.

[Display omitted] • Self-healing hydrogel with multi surface adhesion as sensors for winter sports was prepared by one-pot method. • The hydrogel could maintain stable for 30 days at room temperature and −18℃. • The hydrogel showed good conductivity (24.29 S m−1 at room temperature, remain 13.45 S m−1 under −18 ℃) to detect human motion and temperature changes. • The hydrogel could absorb 100% UV light with the thickness of only 0.5 mm. Hydrogels are widely used as sensors in the field of wearable devices. However, the hydrogels were rarely designed to endure the harsh outdoor environment in winter, including extremely low temperature, ultraviolet (UV) radiation and variable humidity. In addition, physical damage is also a challenge for hydrogels. In this study, a self-healing hydrogel with adhesion was prepared as a sensor for winter sports using a one-pot method. Polyvinyl alcohol was used as the hydrogel matrix, providing the hydrogel preferable self-healing properties and adhesion to various surfaces such as porcine skin, metal, glass, and plastic. Lithium chloride was used for the chain entanglement of polyvinyl alcohol, forming a hydrogel with excellent ionic conductivity (24.29 S m−1 at room temperature, 13.45 S m−1 under −18 ℃) to detect human motion and temperature changes. Together with ethylene glycol, lithium chloride also provided successful water retention ability and frost resistance. The hydrogel remained stable after 30 d of storage at room temperature and −18 ℃. Sodium lignosulfonate was introduced to improve the mechanical properties and ultraviolet (UV) resistance of hydrogel, created nearly 100% UV shielding with a thickness of 0.5 mm. These advantages provide great potential to the hydrogel for application in flexible wearable devices for winter sports. [ABSTRACT FROM AUTHOR]

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Abstract Background Ethylene glycol (EG) (antifreeze) toxicosis has mostly been reported in dogs and cats, while reports on EG toxicosis in cattle are sparse. We report EG toxicosis in 25 milk-fed calves associated with a leak in the cooling pipes in a milk taxi. The milk taxi was connected to a geothermal heating system in which EG was used as antifreeze. Case presentation Although the assistant responsible for feeding milk to the calves observed a few blue-colored droplets of liquid on the surface of the milk in the milk taxi and suspected EG contamination, the milk was fed to the calves. Within hours, the calves became depressed and some died within the next 2 days. Necropsy and histopathology revealed widespread severe acute renal tubular necrosis with numerous birefringent crystals in the tubular lumen. Biochemical analysis of serum showed severe damage to the kidneys (marked azotemia) and hypochloremia, hyponatremia and hyperkalemia; findings consisting with metabolic acidosis. After feeding the calves, the assistant inspected the milk taxi and found a leaking cooling pipe. Conclusions The suspected EG toxicosis was confirmed by the observation of renal tubular necrosis, numerous intratubular crystals, and metabolic acidosis. EG toxicosis due to leaking pipes connected to a geothermal heating system has not been reported previously. Alternative antifreeze products that are less toxic than EG are recommended for use if there is a risk of contamination of human and animal foodstuffs in case of a leak in the system.

Zwitterionic hydrogels have emerged as a promising option due to their remarkable ionic conductivity. However, these hydrogels often suffer from poor mechanical properties due to their super hydrophilicity. Herein, we propose the use of a rigid aryl imidazolium monomer (AIm) for crosslinking with poly(vinyl alcohol) (PVA) to create a unique zwitterion hydrogel. Chlorosulfonic acid acts as an agent to introduce anionic groups, facilitating the transfer of Zn2⁺ ions in zwitterionic hydrogel. We achieve extraordinary mechanical properties by incorporating an optimal amount of AIm into the PZW2 hydrogel (tensile stress 0.9 MPa and stretch 1400 %). Above all, the PZW2 hydrogel exhibits remarkable resistance to freezing, remaining unfrozen even at up to −80 °C. This anti-freezing property is attributed to the cation-dipole interactions and the presence of ZnCl 2 , effectively preventing water from freezing within the hydrogel structure. Furthermore, the PZW2 hydrogel demonstrates a high ionic conductivity of 4.34 S m−1 at room temperature. This can be attributed to the presence of anionic and cationic charges within the PZW2 hydrogel, which facilitates the transfer of ions through a hopping mechanism. The PZW2 hydrogel demonstrates better performance compared to most antifreeze conductive hydrogels. At −20 °C, it achieves an impressive ionic conductivity of 2.73 S m−1 and retains outstanding mechanical characteristics with a stretchability of 1000 %. Ultimately, the PZW2 hydrogel demonstrates a sensitive response performance with a gauge factor of 1.59, making it highly suitable for potential sensor applications. [Display omitted] • A rigid aryl imidazolium monomer was proposed to crosslink with poly(vinyl alcohol) and form a unique zwitterion hydrogel. • Incorporating an optimal amount of AIm into the PZW2 hydrogel, showed a tensile stress of 0.9 MPa and a stretch of 1400 %. • The PZW2 hydrogel exhibits remarkable resistance to freezing, remaining unfrozen even at up to -80 °C. • The PZW2 hydrogel shows a high ionic conductivity of 4.34 S m-1 and 2.73 S m-1 at 25 °C and -20 °C, respectively. • The PZW2 hydrogel shows a sensitive response with a gauge factor of 1.59, making it ideal for sensor applications. [ABSTRACT FROM AUTHOR]

The study is dedicated to the consideration of lower alkyl ethers of glycerol as potential components of low-melting technical fluids (e.g., heat transfer fluids, hydraulic fluids, aircraft de-icing fluids, etc.). Four isomeric mixtures of glycerol ethers (GMME—monomethyl; GDME—dimethyl; GMEE—monoethyl; GDEE—diethyl) were synthesized from epichlorohydrin and methanol/ethanol in the presence of sodium and subjected to detailed characterization as pure compounds and as aqueous solutions (30–90 vol%). The temperature and concentration dependencies of density, viscosity, cloud point, boiling range, specific heat capacity, thermal conductivity, and rubber swelling were obtained. On the basis of the data obtained, a comparison was made between the aqueous solutions of glycerol ethers and of other common bases for low-melting liquids (glycerol, ethylene glycol, and propylene glycol). Pure glycerol ethers could potentially be used as technical fluids in a very wide temperature range—from −114 to 150 °C. It was further demonstrated that in low temperature applications (e.g., in low-temperature chiller systems) the glycerol-ether-based aqueous heat transfer fluids could provide enhanced efficiency when compared to the glycerol- or propylene-glycol-based ones due to their lower viscosities and favorable environmental properties.

The results of diagnostics of antifreeze indicators before and after their operation in an internal combustion engine are presented. The chosen direction of research is relevant, since it allows one to predict not only the change in the properties of antifreeze during its operation, but also to obtain evidence of the course of metal corrosion processes. The purpose of the study - to conduct control tests of antifreezes before and after their operation in an internal combustion engine, that ensures the maintenance of the power unit in good condition. The objects of study were fresh AGA Z-40-G12++ antifreeze (release of 2021; A-21) and coolant AGA Z-40-G12+ (release of 2012; AE-12) after its operation for several years. It is shown that the pH, density, viscosity, electrical conductivity of the coolant samples before and after its operation are different. It was found that the course of the dependences of electrical conductivity on temperature t for samples A-21 and AE-12 is the same. The dependence of on t is described by a polynomial (quadratic) model. It has been suggested that higher values of the AE-12 hydrogen index may indicate the occurrence of electrochemical corrosion of metals, which, in the process of contact with antifreeze, form short-circuited galvanic pairs. With the help of a complete factorial experiment, it was demonstrated that higher pH values of used antifreeze can be a reflection of the degradation of the properties of monoethylene glycol and the ongoing processes of metal corrosion.

The main part of this article describes the solution of the technical problem of creating a solar water heater device that allows to increase energy efficiency while ensuring safety, sanitary requirements and indoor microclimate. Information is given about the proposed device and method for eliminating leaks on heat-transfer pipes and their connections by automatically sealing poisonous (antifreeze), limiting the risk of its possible ingress into heated water for domestic needs. The report also provides a brief rationale for introducing a new discipline into the educational process related to the tasks under consideration. [ABSTRACT FROM AUTHOR]

In this study, the stability, thermal conductivity and viscosity of carbide-derived carbon antifreeze thermal fluids were explored. The study also compares the results between antifreeze suspensions prepared using oxidized CDC and emulsified CDC using gum arabic. At first, the raw CDC was oxidized with oxygen by acid treatment and the Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy results revealed an increase in the oxygen content and oxygen functional groups in oxidized CDC. The two-step method was utilized for CDC thermal fluids preparation. Sedimentation visualization and zeta potential testing were employed to investigate stability of nanofluids with time. The stability results revealed that the oxidized CDC has better stability and higher zeta potential values than the emulsified CDCs; however, both mixtures demonstrated stable suspensions for three months. Viscosity measurements showed that the gum arabic CDC suspensions have a higher viscosity than the oxidized CDC; the viscosity was growing with CDC and gum arabic loadings and decreased with temperature. The thermal conductivity analysis was carried out using a lambda analyzer in a temperature range of 288–338 K with a CDC mass loading range of 0.05–0.3 mass%. The experimental outcomes demonstrated that oxidized CDC suspension has better thermal conductivity than gum arabic emulsified CDC. The highest improvement in thermal conductivity was 25.6% using 0.3 mass% of oxidized CDC at 338 K. Moreover, raising the gum arabic mass loading was found to reduce the thermal conductivity enhancement. Therefore, according to the results, the oxidized CDC antifreeze suspensions can perform better than the emulsified CDC. [ABSTRACT FROM AUTHOR]

Gel electrolytes have emerged as a versatile solution to address numerous limitations associated with liquid electrolytes in electrical energy storage (EES) devices, in terms of safety, flexibility, and affordability. Aqueous gel electrolytes, in particular, exhibit exceptional features by offering one of the highest ion solvation capacities and ionic conductivities. The two main challenges with hydrogel electrolytes are their easy freezing at subzero temperatures and rapid dehydration under open conditions, leading to the failure of the EES device. In response, we present an uncomplicated and quick-to-make hydrogel electrolyte system offering impressive mechanical properties (205.5 kPa tensile strength, 2880 kJ/m 3 toughness, and 3030% strain at the break), along with antifreezing and antiflammability attributes. Notably, the hydrogel electrolyte demonstrates high ionic conductivity and superior performance in supercapacitor cells over a wide range of temperatures (-40 to 80 °C) and under various deformations. The hydrogel electrolyte maintains its capabilities under open conditions over an extended period of time, even at 50 °C, showcased by powering a wristwatch. The atmospheric stability of the hydrogel electrolyte demonstrated in this study introduces promising prospects for the future of EES devices spanning from production to end-user consumption.

Alginate organohydrogels prepared in water/alcohol mixtures play an important role in electronic and superconductor applications in low-temperature environments. The study deals with the preparation of Ca-alginate organohydrogels and the analysis of their equilibrium swelling and mechanical properties at sub-zero temperatures. It is shown that the equilibrium degree of swelling at room temperature is noticeably affected by the concentration of co-solvents (methanol, ethanol, and 2-propanol) in the mixtures and the number of carbon atoms in the co-solvent molecules. Mechanical properties are studied in small-amplitude oscillatory tests. The data are fitted with a model that involves three material parameters. The influence of temperature is investigated in temperature-sweep oscillatory tests under a cooling-heating program, where a noticeable difference is observed between the storage and loss moduli under cooling and heating (the hysteresis curves). The hysteresis areas are affected by the cooling/heating rate and the number of carbon atoms in the co-solvents.

In this paper, PVA/PAA‐PAM‐IS/GC composite hydrogels are prepared using polyvinyl alcohol (PVA), poly acrylic acid (PAA), poly acrylamide (PAM), and iron sulfate hydrate (IS) glycerol (GC). The crosslinking network is formed by the coordination of carboxyl groups with ions, which forms PVA with semi‐interpenetrating network. The mechanical properties and self‐healing properties of PVA/PAA‐PAM‐IS/GC composite hydrogels are excellent. The stress, strain and self‐healing efficiency of PVA/PAA‐PAM‐IS/GC composite hydrogels can reach 840 kPa, 784%, and above 95%, respectively. The antifreeze and water retention properties of PVA/PAA‐PAM‐IS/GC composite hydrogels are improved by glycerol. PVA/PAA‐PAM‐IS/GC composite hydrogels remains flexible at low temperatures and moist for a long time at room temperature. The conductivity of the hydrogel increases with the increase of temperature because the interactions between glycerol, water molecules and ammonium ions are affected by the temperature, the multifunctional conductive hydrogel can be used in strain sensing and temperature sensing. In summary, PVA/PAA‐PAM‐IS/GC composite hydrogels can provide a guide in the field of electronic intelligence. [ABSTRACT FROM AUTHOR]

Conductive hydrogels have become one of the most promising candidates for flexible electronics due to their excellent mechanical flexibility, durability of deformation, and good electrical conductivity. However, in real applications, severe environments occur frequently, such as extremely cold weather. General hydrogels always lack anti-freeze and anti-dehydration abilities. Consequently, the functions of electronic devices based on traditional hydrogels will quickly fail in extreme environments. Therefore, the development of environmentally robust hydrogels that can withstand extremely low temperatures, overcome dehydration, and ensure the stable operation of electronic devices has become increasingly important. Here, we report a kind of graphene oxide (GO) incorporated polyvinyl alcohol-polyacrylamide (PVA-PAAm) double network hydrogel (GPPD-hydrogel) which shows excellent anti-freeze ability. The GPPD-hydrogel exhibits not only good flexibility and ultra-high stretchability up to 2,000%, but ensures a high sensitivity when used as the strain sensor at −50 °C. More importantly, when serving as the electrode of a sandwich-structural triboelectric nanogenerator (TENG), the GPPD-hydrogel endows the TENG high and stable output performances even under −80 °C. Besides, the GPPD-hydrogel is demonstrated long-lasting moisture retention over 100 days. The GPPD-hydrogel provides a reliable and promising candidate for the new generation of wearable electronics. [ABSTRACT FROM AUTHOR]

In this study, the effects of using different water-ethylene glycol mixture rates on heat transfer performance put in an automobile radiator as a liquid is experimentally analysed. Ethylene glycol is added in water volumetrically and experiments are conducted for 0%, 25%, 50%, 75% and 100% volumetric ratio of ethylene glycol. For all these mixture rates, 300 experiments are conducted for fluid inlet temperature between 40-80 °C, fluid inlet flow rate between 10-22 l/min and cooling air between 1-4 m/s. As a result of the experiments, it is observed that as ethylene glycol mixture ratio passing from the radiator increased, heat transfer decreased. However, as cooling air velocity, fluid inlet flow rate and radiator inlet temperature increased, heat transfer increased as well. When water-ethylene glycol mixture is used in the radiator instead of water, it is observed that radiator fluid freezing temperature decrease and radiator heat transfer performance is negatively impacted. As a result, optimum cooling performance for the automobile radiator was determined at 0% EG mixture (only water), fluid inlet temperature of 80°C, the flow rate of 22 l/min and air velocity of 4 m/s.

In the current experimental investigation, the radiators’ heat transfer performances are evaluated experimentally and validation is done using the analytical ε-NTU method. In this experimental study composition of the cooling fluid is 50:50 water/EG. The pressure and temperature values are fixed for air and water/ethylene glycol sides. The velocity of air is between 1.5−12 m/s and water/ethylene glycol flow rate is between2.5−7 kg/s. All measurements are performed after steady state is reached. For altering operation conditions, the overall heat transfer coefficient, exit water/ethylene glycol temperature, pressure drop and friction coefficients are evaluated experimentally. Both rate of heat transfer and the pressure drop are maximum for the double U grooved case. For the tested radiator categories, the overall heat transfer coefficient rose with increasing coolant and air velocity and the exit temperature raised with increased coolant flow rate and decreased with increasing velocity of air.

According to laboratory data, the thermal conductivity ratio of an antifreeze-based hybrid nanofluid containing graphene oxide (GO) and Copper oxide (CuO) was modeled using mathematical methods, one is based on an artificial brain structure model, and the other is based on curve-fitting method. A two-variable empirical based correlation (R2 = 0.996) as a function of temperature and volume fraction suggested from the curve-fitting method. In the brain structure-based section, an artificial neural network employed by applying temperature and concentration as input variables and thermal conductivity ratio as the desired output. The correlation coefficient (R) values of designed ANN are 0.999963, 0.999409, and 0.999103 for train, validation and test, respectively. Mean squared errors (MSE) values of designed ANN are 1.01743e-6, 5.01019e-5, and 2.90237e-5 for train, validation and test, respectively. The findings indicated that the artificial neural network and the proposed correlation can predict the thermal conductivity ratio of GO-CuO (50:50%)/EG-Water (50:50%) hybrid nanofluid with high accuracy.

In order to investigate the durability of concrete under alternating curing from −20℃ to 20℃, different antifreeze (JB-1 type/HD-type) and different dosages (1.5 wt%/2 wt%) were chosen to carry out the study. This study used a variety of tests such as rapid freeze-thaw test, freeze-thaw-sulfate coupling test, dry and wet cycle test, electrical flux test, and drying shrinkage test, combined with NMR techniques, to comprehensively evaluate the properties and pore structure of the concrete. The results show that adding antifreeze can optimize concrete durability and pore structure under alternating curing from −20°C to 20°C. This study showed that 1.5 wt% was the optimal dose to maximize the improvement of concrete durability. Comparative analysis revealed that JB-1 type antifreeze is superior to HD-type antifreeze in enhancing the frost resistance, the freeze-thaw-sulfate coupling resistance, and the chloride ion permeation resistance of concrete, which is manifested in the relative dynamic modulus of elasticity increase of 1.5 %, compressive strength increase of 1.5 MPa, mass loss decrease of 0.12 % and electric flux decrease of 86 C. In-depth investigation reveals that the JB-1 type antifreeze agent promotes the generation of C-S-H gel by accelerating the hydration process of concrete, fills and shrinks the micropores of concrete, reduces the porosity, and improves the microstructure. However, over-addition has a reverse effect, which enhances the content of tiny bubbles and leads to a 2.4 % decrease in the relative dynamic modulus of elasticity of concrete. Meanwhile, the increase in porosity leads to an increase in the electrical flux of concrete by 151 C and shrinkage by 17.2 μm. • To study the effect of alternating positive and negative temperatures from −20℃～20℃ on the durability of concrete. • Analyze the effect of different types and doses of antifreeze on the durability performance of concrete. • To analyze the effect of alternating positive and negative temperatures on concrete porosity based on NMR technique. [ABSTRACT FROM AUTHOR]