Hydration Behavior Research Articles

Hydration behavior of L-proline in the presence of mono, bis, tris-(2-hydroxyethyl) ammonium acetate protic ionic liquids: Thermophysical properties

The hydration behavior of amino acids, essential for biological macromolecules, is influenced by ammonium biomaterials. The protic ionic liquids (PILs) are gaining attention in the food and pharmaceutical industries due to their nontoxicity and adjustable properties. Thus, study of the amino acids, such as L-proline, in the presence of PILs is crucial for understanding their hydration behavior. In this work, the effect of PILs, including mono, bis, tris (2-hydroxyethyl)ammonium acetate protic ionic liquids that might be naturally produced in human body, on L-proline hydration behavior was studied using COSMO calculations and thermophysical measurements. Measurements were the density, speed of sound, viscosity, and refractive index data of the solutions (L-proline + PILs + water) at various PIL concentrations at temperatures (298.15 to 318.15) K and under atmospheric pressure. The study indicates L-proline has weaker interactions with water compared to PILs ([2-HEA][Ac], [bis-2-HEA][Ac], and [tris-2-HEA][Ac]) due to its compact structure and lower negative dielectric energy. PILs interact more strongly with water through hydrogen bonding. Increasing temperature affects L-proline’s hydration layer, releasing more water molecules compared to PIL solutions. This effect is more pronounced with [tris-2-HEA][Ac], likely due to its larger size and complex structure. While L-proline promotes an ordered water structure, PILs can disrupt this by rearranging water molecules and forming their own hydrogen bonds.

Solvation phenomena in ternary system tetramethylurea-methylacetamide-water: Insights from volumetric, compressibility and FTIR analysis

The properties of the ternary systems N,N,N',N'-tetramethylurea - N-methylacetamide - water were investigated using Fourier-transform infrared spectroscopy (FTIR), volumetric and compression measurements. Densities and sound velocities were determined in order to obtain the apparent molar volumes (VΦ) and apparent molar isentropic compressions (▪S,Φ). These values were then extrapolated to infinite dilution. Additionally, interaction parameters were calculated from the McMillan-Mayer theory. The studies were conducted at 288.15, 298.15, and 308.15 K, at atmospheric pressure (0.1 MPa). The concentration ranges of N-methylacetamide were 2, 4, 6, and 8 moles per kilogram of pure water, and for N,N,N',N'-tetramethylurea from 0 to around 0.35 moles per kilogram of solvent. Discrete changes in isentropic compression were observed. This is the result of the alignment of plots of ▪S,Φ0 as a function of NMA concentration. The results for N,N,N',N'-tetramethylurea were compared with analogous data for the system containing n-butylurea, which is an isomeric compound but exhibits different hydration behaviour. Additionally, large volumetric interaction coefficients were observed, indicating strong interactions between urea derivatives and NMA. This suggests the possibility of strong interactions between protein destabilizers and the protein backbone, differing from those observed for protein structure stabilizers. The observation contributes to understanding the mechanism of osmolyte action and their influence on protein stability.

An investigation into the microstructural evolution and shrinkage control in internally cured mortars with milkweed fibres

This study presented a significant advancement in the use of Milkweed (MW) fibres as internal curing agents in low water-to-cement (w/c) cementitious materials. The research focused on how different pre-treated MW fibres, with different composition, can impact internal curing efficacy in reducing autogenous shrinkage of cement mortars. In addition, the hydration behaviour and microstructural development were revealed using a series of tests including setting time, compressive strength, flexural strength, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA/DTG). A key finding of this study is the remarkable reduction in autogenous shrinkage, with using 0.1 % wt. pre-treated MW fibres leading to up to 28 % reduction at 7 days, compared to plain mortars. Furthermore, internal curing effect resulted in narrowing the compressive strength gap between the reference mixes and those with pre-treated MW fibres in the later stages of hydration. It was also found that the removal of hemicellulose through hybrid treatment can reduce the delay in the final setting time of cement from 45 minutes to 18 minutes. Additionally, while the incorporation of N- and HT-treated MW fibres had negligible effects on drying shrinkage, the inclusion of HY-treated MW fibres led to a 15 % increase in drying shrinkage at 7 days. This difference in behaviour was attributed to the presence of lignin in N- and HT-treated fibres. Lignin was found to play a crucial role in influencing the drying shrinkage, microstructural development, and mechanical properties of MW fibre-incorporated cementitious mixes. Acting as a protective barrier, lignin shielded the MW fibres from cement infiltration into their lumina. Moreover, it served as both a physical and chemical barrier, reducing moisture transport through the capillary network during drying. In conclusion, this study demonstrated the potential of using pre-treated MW fibres as internal curing agents to effectively reduce autogenous shrinkage, with minimal compromise in terms of the compressive strength of cementitious composites.

Cooperative stabilization of calcium carbonate powder, blast furnace slag, and white cement in composite concrete: Volume variation and hydration behavior

Volume stability was an important property of white concrete in long-term service. The purpose of this research is that volume stability of composite concrete was advanced by synergy of calcium carbonate powder and blast furnace slag, and its related hydration behavior was revealed. The results manifested that the early shrinkage, dry shrinkage, and creep of calcium carbonate powder-blast furnace slag-based white concrete (C20) were the lowest as content of calcium carbonate powder and blast furnace slag were 20 % and 10 %. Furthermore, early shrinkage, dry shrinkage, creep, and 120-days compressive strength of C20 were 52.49 %, 24.83 %, 22.47 %, and 82 MPa respectively, which superior to those of others white concrete. These results indicated that the long-term volume stability and strength of C20 was optimal. Information of hydration heat showed that accumulate hydration heat about C20 was minimum (226.91 J/g). This find proved that the effects of thermal expansion and cooling shrinkage on the volume of C20 were ameliorated efficiently. The results of microstructure, mineral phase, and pore structure demonstrated that dense degree of white concrete was boosted by flocculation gel product and rod ettringite. Therefore, the volume stability of white composite concrete could be enhanced by synergy of calcium carbonate powder, blast furnace slag, and white cement.

Physical properties and hydration behaviors of paste casting brick containing coal gasification slag (CGS): Effect of curing condition and CGS dosage

In the process of developing coal chemical technologies, it is necessary to address environmental pollution and resource waste caused by the associated solid waste coal gasification slag (CGS). This study investigated the feasibility of using CGS as a substitute for fly ash (FA) in the preparation of paste casting bricks. The effects of curing conditions and CGS dosages on the physical properties of the specimens were investigated and related to the hydration behaviors through various microscopic techniques. The results showed that the occurrence of electrostatic flocculation and the enrichment of active substances increased the yield stress of the slurry as the CGS replacement rose, which manifested as decreased fluidity at the macroscopic level. The secondary hydration reaction was facilitated with the increased CGS replacement rate due to the desirable hydraulic activity of CGS. XRD, FTIR and TG results corroborated that the content of hydration products which contributed to strength development were enhanced with the addition of CGS under different curing conditions. XRD and SEM-EDS results indicated that the doping of elements such as Mg and Al under autoclaved condition led to a reduction in the grain size of tobermorite, and the micro-morphology tended to concentrate stresses under pressure. The results of this study promote the resourceful utilization of CGS in building materials and lay the foundation for further scale-up industrial application.

Temperature and Pore Pressure Dependencies of the Mechanical Behavior of Methane Hydrate–Bearing Fine-Grained Sediment

Temperature and Pore Pressure Dependencies of the Mechanical Behavior of Methane Hydrate–Bearing Fine-Grained Sediment

Belite–ye’elimite–ferrite cements produced from London Clay

London Clay (LC) is generated in significant quantities from major infrastructure development projects within and around London, UK. Excavated LC spoils are typically landfilled or used for landscaping purposes with minimal value. This study investigates the feasibility of producing belite–ye’elimite–ferrite (BYF) cements using LC in combination with kaolin or low-grade bauxite. Six cement clinkers with varying compositions were synthesised at 1300°C. The phase composition of the synthesised clinkers was quantified using X-ray diffraction analysis (XRD) coupled with Rietveld refinement. The hydration behaviour, phase assemblage evolution and mechanical performance of the cements were examined using isothermal calorimetry, XRD, thermogravimetric analysis and compressive strength testing, respectively, up to 90 days of curing. It is demonstrated that LC can be used either on its own or with kaolin or low-grade bauxite to produce BYF cements with a wide range of composition: 31 to 64 wt% belite, 9.3 to 27 wt% ye’elimite and 2.1 to 31 wt% ferrite. The use of LC as the sole alumina source resulted in low compressive strength at early stages. Nevertheless, the strength developed over time, reaching 27.8 MPa at 90 days (0.5 w/b). Possible approaches to develop LC further for producing viable BYF cements are discussed.

Atomistic Simulations of Hydration and Antibiofouling Behavior of Amphiphilic Polymer Brush Surfaces Functionalized with TMAO and Short Fluorocarbon.

Developing fouling-resistant materials is of paramount interest in marine industries and biomedical applications. In this work, we studied the interfacial hydration and surface-protein interactions of the amphiphilic brush surface functionalized with hybrid hydrophilic trimethylamine N-oxide (TMAO) and hydrophobic pentafluoroethyl groups using a combination of atomistic molecular dynamics simulations and free-energy computations. Our results show that while the interfacial hydration density of the amphiphilic surface slightly decreases with the introduction of small fluorocarbons compared to that of the pure TMAO-functionalized surface, the amphiphilic surface remains relatively strong in resisting protein adsorption. The nanosized clustering of hydrophobic fluorine atoms on the top of the amphiphilic brush surface introduces weak protein adsorption; however, due to the strong interfacial hydration and weak hydrophobic interaction, the amphiphilic surface exhibits sufficient antibiofouling activities. Our fundamental studies will be critical for the discovery of marine fouling-resistant coating surfaces.

Experimental study on infrared detection of debonding in concrete-filled steel tubular structure under acceleratory period of hydration heat action

Concrete-filled steel tubular (CFST) Structures often face challenges with debonding during construction, which can markedly compromise the structural integrity. The hydration of concrete can generate significant heat during construction, making the infrared thermography as a potential method for the defect detection. However, effects of concrete hydration behavior, debonding size, and environmental factors on the infrared thermal imaging of CFST debonding remains unclear. This study conducted experiments using four different hydration heating rates and three debonding sizes to simulate debonding detection using infrared imaging during the hydration phase of CFST. The feasibility of the simulation approach was validated through pair-to-pair comparison, and multiple linear regression analysis was employed to evaluate the impact of these factors. The findings highlight that absolute temperature difference has the most significant impact on detection effectiveness regardless of interaction effects. In regression models without interaction, heating rate demonstrated the least impact, Whereas the model considering the interaction showed that the interaction effect of heating rate and debonding size showed a secondary effect. Further examination indicated that interaction effects decrease as heating rate and debonding size decrease.

Hydration behavior of D-calcium pantothenate (vitamin B5) in the presence of sugar-based deep eutectic solvents at different temperatures: experimental and theoretical study

Considerable efforts have been devoted in recent years to enhancing the efficacy medicinal substance, leading to the discovery of innovative drug formulations and delivery techniques. The successful design of these processes necessitates a profound understanding at the molecular level of how these substances interact with biological membranes. Thorough thermodynamic investigations provide invaluable insights into these interactions and aid in selecting suitable compounds for pharmaceutical production. This study aims to determine the density and speed of sound for D-calcium pantothenate in mixtures of water and deep eutectic solvents (DESs), specifically choline chloride/sucrose, choline chloride/ glucose, and choline chloride/ fructose (with 2:1 molar ratio) over a temperature range of 288.15 K to 318.15 K under atmospheric pressure. In order to predict the behavior of molecules, COSMO model (the Conductor-Like Screening Model) offer complementary strengths in quantum chemistry. This approach allows for calculating solvation free energies, making it ideal for predicting properties like solubility, where understanding solvent-solute interactions is crucial. By correlating the measured parameters using standard relationships, important partial molar parameters such as apparent molar volumes and apparent molar isentropic compressibility are calculated. Additionally, apparent molar isobaric expansion, and Hepler’s constant are derived from the density and speed of sound data. The experimental apparent molar volumes, and apparent molar isentropic compressibility data is fitted to the Redlich-Meyer equation to obtain significant quantities such as standard partial molar volume, and partial molar isentropic compression. The comprehensive thermodynamic analysis of this studied system holds immense significance for advancements in the pharmaceutical industry.

Water Uptake of Airborne Cells of P. syringae Measured with a Hygroscopicity Tandem Differential Mobility Analyzer.

Airborne microorganisms impact cloud formation and are involved in disease spreading. The ability of airborne cells to survive and express genes may be limited by reduced water availability in the atmosphere and depend on the ability of the cells to attract water vapor at subsaturated conditions, i.e., their hygroscopicity. We assessed hygroscopic properties of the plant pathogen Pseudomonas syringae, known to participate in cloud formation. We used a hygroscopicity tandem differential mobility analyzer to examine both hydration and dehydration behavior in the relative humidity (RH) range 5-90%. The cells were aerosolized either from Milli-Q water or from a 35 g L-1 NaCl solution, resulting in pure cells or cells associated with NaCl. Pure cells exhibited no deliquescence/efflorescence and a small gradual water uptake reaching a maximum growth factor (GF) of 1.09 ± 0.01 at 90% RH. For cells associated with NaCl, we observed deliquescence and a much larger maximum GF of 1.74 ± 0.03 at 90% RH. Deliquescence RH was comparable to that of pure NaCl, highlighting the major role of the salt associated with the cells. It remains to be investigated how the observed hygroscopic properties relate to survival, metabolic, and ice-nucleation activities of airborne P. syringae.

High-entropy design of Ruddlesden-Popper structured LNO for enhanced performance in proton solid oxide fuel cells

Protionic Ceramic Fuel Cells (PCFCs) are devices that efficiently convert chemical energy to electrical energy at low temperatures. Significant research efforts have been directed towards the development of cathodes with enhanced catalytic activity. In this work, a high-entropy approach was employed at the A site of La2NiO4+δ (LNO) with a Ruddlesden-Popper (R-P) structure, resulting in the synthesis of the LaPr0.2Sm0.2Ba0.2Sr0.2Ca0.2NiO4+δ (HE-LPSBSCN) cathode. A comprehensive series of tests demonstrated that this high-entropy strategy improved the oxygen reduction reaction (ORR) activity, hydration behavior, well operational stability, and electronic conductivity of LNO. The HE-LPSBSCN cathode demonstrated record-breaking performance, achieving a maximum power density of 2004 mW cm−2 at 700 °C. This finding provides novel insights for the rational design and optimization of highly catalytically active cathodes for PCFCs.

The impact of relative humidity on the nanoindentation relaxation in calcium silicate hydrates

Despite extensive research efforts, understanding the time-dependent behavior of concrete remains an enigma due to the complex nature of cement microstructure. In this study, the statistical nanoindentation was employed to investigate the influence of relative humidity (RH) on the relaxation behavior of calcium silicate hydrates (C-S-H) in a cement paste. Our experiments, performed at RH levels of 33 % and 86 %, revealed significant enhancements in both the indentation modulus and hardness of the C-S-H as RH increased. Remarkably, the internal water exerted a significant influence on the asymptotic relaxation behavior, displaying a clear power-law fashion. Further analysis identified the presence of short- and long-term viscoelastic behaviors within the C-S-H, distinguished by a transition observed within the initial seconds. These findings advance the understanding of nanoscale mechanisms driving concrete creep under different humidity conditions.

Rheological behavior of deep eutectic solvent promoted methane hydrate formation

Natural gas hydrates are recognized as a crucial and sustainable energy resource. The formation, dissociation, and flow properties of CH4 hydrate from deep eutectic solvents (DESs) are investigated using a high-pressure rheometer. In this work, rheological experiments are performed using two DESs namely, tetrabutylammonium bromide + ethylene Glycol (TBAB + EG, DES1) and methyltriphenylphosphonium bromide + ethylene Glycol (MTPB + EG, DES2) at 1 wt% concentration, 274 K temperature and 8 MPa pressure. The hydrate formation starts around 1.7 h for DES1 and around 4 h for DES2. Pressure and viscosity of the slurry are analyzed while methane hydrate forms and dissociates. The pressure drop experienced during hydrate formation is roughly 1.4 MPa for DES1 and 1.7 MPa for DES2. Further, viscosity profiles are analyzed for both DESs with varying shear rate. The viscosity gradually decreases as the shear rate increases. At equilibrium conditions of pure CH4, a spike is observed during dissociation. The rheological data is further analyzed with Cross model to validate the shear-thinning behavior of methane hydrate.

Two-Dimensional Hydration and Triple-Interlayer Lattice Structures in Sulfate-Intercalated Graphene Oxide Nanosheets

Sulfate anions (SO42−) are pivotal in various scientific and industrial domains, including mineralogy, biology, and materials science. While extensive research has elucidated sulfate hydration in bulk solids, liquids, and gaseous clusters, a significant gap persists in understanding sulfate interactions within two-dimensional materials, particularly graphene oxide (GO) nanosheets. This study investigates the intricate hydration phenomena and novel triple-interlayer lattice configurations that emerge from sulfate intercalation in GO nanosheets. Utilizing a straightforward methodology for obtaining precise X-ray measurements of confined nanospaces, we analyzed the temperature-dependent behavior and structural characteristics of these systems. Our findings reveal how sulfate ions modulate interlayer spacing, the dynamics of GO layers, and phase transitions. This research offers an atomic-scale understanding of hybrid hydration behaviors within confined SO4-H2O nano-environments, advancing our knowledge of sulfate interactions in two-dimensional materials.

Determining the Hydration Knowledge Level, Attitudes and Behaviors of Athletes In Different Sport Events

This research aimed to examine the hydration knowledge level, attitudes and behaviors of athletes in different sport events. A total of 553 athletes, 123 (22.2%) females and 430 (77.8%) males, were included in the research conducted with the screening model. The data was obtained by using the "Personal Information Form" and the "Hydration Knowledge, Attitude and Behavior Survey". T-test for independent groups and one-way analysis of variance were used in the analysis of data. When the research findings were examined, it was determined that there were statistically significant differences in athletes' attitudes and behavior according to gender, attitude according to sport type, knowledge and behavior according to age groups, knowledge, attitude and behavior according to sports age, and knowledge and behavior according to their educational status. As a result, it was determined that the athletes' general knowledge scores were at a high level, while their attitude and behavior scores were at a medium level.

Synergistic effects of waste coral powder and metakaolin in cement pastes: Hydration, pore structure, rheology, and strength

Coral reefs are abundant in waste coral powder, and how to utilize coral powder efficiently to construct far-sea projects has become a major focus of research and engineering field, which is conducive to the development of green economy. However, existing research lacks a comprehensive and systematic investigation of the cement-coral powder-metakaolin ternary system. In this study, the hydration and rheological behavior, micromechanical and mechanical properties, and pore structure evolution of the ternary system are systematically investigated to uncover the synergistic mechanism between metakaolin and coral powder. The results indicated that, based on hydration, rheology, and mechanical properties, the recommended proportions of cement, coral powder, and metakaolin are 75 %, 10 %, and 15 %, respectively. The combination of coral powder and metakaolin effectively promotes hydration. Furthermore, it accelerates the aluminate reaction, resulting in a stronger aluminate exothermic peak immediately. In addition, metakaolin reacts with coral powder to form carboaluminate, activating the activity of the coral powder, which in turn improves the mechanical properties and pore structure of the ternary system. Moreover, metakaolin undergoes a pozzolanic reaction with calcium hydroxide, which contributes to optimizing the pore structure of the ternary system and enhancing its mechanical properties. Additionally, coral powder promotes the conversion of monosulfate to carboaluminate while inhibiting the transformation of ettringite into monosulfate. The Herschel-Bulkley model accurately simulates the dynamic rheological behavior of the ternary system. This study is highly significant and practically valuable for transforming waste coral powder into a supplementary cementitious material for the construction of the far-sea projects, providing a scientific basis for future related studies.

A closed-loop recycling of wastewater derived from aqueous carbonation of basic oxygen furnace slag in cement paste production

Aqueous carbonation (AC) treatment is a promising method for enhancing the cementitious activity of Ca- and Mg-rich solid wastes, such as basic oxygen furnace slag (BOFS), while also reducing carbon emissions. However, the carbonated filtrate (CF) solution generated during the AC process poses significant environmental challenges and limits its large-scale application. This paper, therefore, explores the feasibility of recycling CF in cement paste production as a strategy for managing AC wastewater. The study examines the impact of CF on the physico-mechanical properties, hydration behavior and microstructure of cement pastes (pure and blended with either 10% as-received or carbonated BOFS), compared to those prepared with tap water (TW) and carbonated water (CW). The results indicate that carbonated solutions (CF and CW) promote the hydration of aluminate phase in cement, with a more pronounced effect observed for CW. The solid suspensions in CF, particularly nesquehonite, restrict the growth space for calcium silicate hydrates (C-S-H) in the paste matrix, resulting in the formation of foil-like Type II C-S-H and lowering compressive strength. However, the additional nucleation sites provided by calcite crystals in carbonated BOFS (C-BOFS) accelerate cement hydration in CF-based pastes and mitigate strength loss by promoting the formation of more fibrillary C-S-H. Furthermore, the addition of a superplasticizer reduces interparticle forces in the C-BOFS-CF paste, further enhancing strength development and achieving a 28-day strength comparable to that of the control sample (OPC-TW paste).

Synthesis and characterization of activated carbon-supported magnetic nanocomposite (MNPs-OLAC) obtained from okra leaves as a nanocarrier for targeted delivery of morin hydrate.

The method of encapsulating the drug molecule in a carrier, such as a magnetic nanoparticle, is a promising development that has the potential to deliver the medicine to the site where it is intended to be administered. Morin is a pentahydroxyflavone obtained from the leaves, stems, and fruits of various plantsmainly from the Moraceae family exhibiting diverse pharmacological activities such as anti-inflammatory, anti-oxidant, and free radical scavenging and helps treat diseases such as diabetes, myocardial infarction and cancer. In this study, we conducted the synthesis of a nanocomposite with magnetic properties by coating biocompatible activated carbon obtained from okra plant leaves with magnetic nanoparticles. Characterization of the synthesized activated carbon-coated magnetic nanocomposite was confirmed by Fourier transform infrared, scanning electron microscopy, dynamic light scattering, and zeta potential. The cytotoxic effects of the drug-loaded magnetic nanocomposite were examined in HT-29 (Colorectal), MCF-7 (breast), U373 (brain), T98-G (Glioblastoma) cancer cell lines, and human umbilical vein endothelial cells healthy cell line. We studied the loading and release behavior of morin hydrate in the activated carbon-coated magnetic nanocomposite. Activated carbon-coated magnetic nanocomposite carriers can show promising results for the delivery of Morin hydrate drugs to the targeted site.

Unveiling the dissolution mechanism of calcium ions from CSH substrates in Na2SO4 solution: Effects of Ca/Si ratio

The decalcification behavior of calcium silicate hydrate (CSH) under sulfate attack poses a critical challenge to the long-term durability of cement-based infrastructure, yet understanding its underlying microscopic mechanisms remains elusive. This study employs molecular dynamics to compare the differences in calcium ion dissolution capability of CSH substrates with varying Ca/Si ratios under sulfate solution exposure. The results show that the dissolution amount and dissolution efficiency of Ca are positively correlated with Ca/Si, and the root cause depends on the basic structure of CSH. With the increase of Ca/Si, the electronegativity of CSH decreases, and the adsorption capacity and stability of cations weaken. Meanwhile, Ca ions are less limited by the silicate chain coordination, water molecules are more likely to invade the substrate interior and replace the Ca ions. This research aims to provide a molecular basis for cement production and durability applications in marine engineering.