Breaking Of Hydrogen Bonds Research Articles

Thermal treatments modulate short-chain fatty acid production and microbial metabolism of starch-based mixtures in different ways: A focus on the relationship with the structure of resistant starch

The physiological function of thermally treated starch-based foods was predictively analyzed by in vitro fermentation. Different thermal treatments affected the structure of resistant starch and the presence of harmful substances. The effect of these treatments on their in vitro fermentation properties was emphasized. In this study, undigested components with different structural characteristics were isolated from starch–protein–oil mixtures treated by thermal treatments (boiling, baking, and frying). The structures of digested residues from different thermally treated ternary mixtures were disrupted to varying degrees compared with the control, as evidenced by the reduction of crystalline regions, the break of inter-molecular hydrogen bonds, and damage to molecular structure of rice starch. Baking (1.381 μg/g) and frying (1.696 μg/g) resulted in higher contents of Maillard reaction products (AGEs) than boiling (1.246 μg/g). After fermentation, the content of short-chain fatty acids generated by thermally treated ternary mixtures lowered, correlating with the incomplete structure of resistant starch. By contrast, the species diversity of intestinal microbes increased in thermally treated groups because of their high intestinal pH, which favored the growth of pathogenic bacteria. In addition, the Bacteroidetes/Parabacteroides ratio of the dominant microbes in thermally treated groups was reduced, which was detrimental to the maintenance of intestinal homeostasis. In particular, the high AGE content in baking and frying groups increased the relative abundance of harmful microbes such as Proteobacteria and Pseudomonas.

Understanding leaching of amylopectin from cellulose/amylopectin/[Bmim][Cl] blends during regeneration from water and aqueous ethanol using molecular dynamic simulations

The difference in amylopectin leaching from cellulose/amylopectin/1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) blends during regeneration in water and aqueous ethanol has been observed in experimental studies. To fully understand the above phenomenon, molecular dynamic simulation was adopted to illustrate the regeneration mechanism after dissolution to understand interactions responsible for the elution/leaching of amylopectin starch. Molecular dynamics (MD) simulations reveal that amylopectin dissolution in [Bmim][Cl] is similar to cellulose in ionic liquids (ILs). Strong hydroxyl-Cl- hydrogen bonding drives dissolution, with [Bmim]+ ions playing a stabilizing role through van der Waals interactions. Amylopectin regeneration in water and aqueous ethanol occurs through the initial disruption of weak hydroxyl-Cl- bridging bonds followed by the disruption of strong non-bridging hydrogen bonds. The water network intercalates amylopectin chains, forming a few “short-lived” interchain HBs. This leaves a very weak electrostatic interaction as the dominant intermolecular interaction between water-regenerated amylopectin chains. Water solvates and elutes low molecular weight amylopectin oligomers, with only 47.29 % amylopectin retained in the blend. In contrast, ethanol-water hydrophobic-hydrogen interactions disrupt the water network, create an ethanol-rich environment, shorten the intermolecular distance between chains, decrease diffusivity, increase hydrogen bonding lifetime between amylopectin, and regenerate amylopectin in aqueous ethanol. The regenerated amylopectin chains interact through improved but weak electrostatic interaction. Improved interaction between chains limits the erosion of low-molecular-weight amylopectin from films retaining 83.11 % amylopectin, approximately two times that in water. At a molecular level, we established that a very weak electrostatic interaction among amylopectin is responsible for leaching in water during regeneration. Ethanol enhances electrostatic interaction among amylopectin chains to limit amylopectin leaching in aqueous ethanol. These observations could apply to other polysaccharide blended materials prepared by the dissolution-regeneration method.

Host-guest dynamics in porous trimesic acid supramolecular network on graphene. Outstanding stability of the coronene guest

We performed reactive molecular dynamics (ReaxFF-MD) simulations to investigate host-guest interactions between the porous honeycomb supramolecular network formed by trimesic acid (TMA) and the following guests: coronene (COR), C60, C84, and C98 fullerenes, a 5-membered cyclodextrin macrocycle (CD5) and pentanoic acid (PA) molecules. Coronene imparts outstanding stability to the TMA network as compared to the other guests. Whereas the fullerenes destabilize the TMA network, CD5 and PA molecules induce a small stabilization. The mechanism of COR-enhanced stability involves synergistic effects between the COR-graphene and COR-TMA interactions. Strongly bound coronene molecules impose steric restraints on the twisting dynamics of carboxylic groups of TMA molecules. This impedes the breakage of hydrogen bonds between the cyclic dimers formed by opposing COOH groups of TMA molecules, which has a stabilizing effect on the network structure up to high temperatures. CD5 molecules have higher host-guest interactions than coronene, however, the TMA/CD5 network has lower thermal stability because CD5 molecules desorb from the pore due to its lower binding energy to graphene. Therefore, an adequate balance between host-guest and guest-surface interactions is required to increase the thermal stability of the host-guest superstructure.

Atomistic Investigation of the occupancy limits and stability of hydrogen hydrates as a hydrogen storage medium

Gas hydrates are nonstoichiometric inclusion compounds which occur via a hydrogen bonded water network. This network forms cages that encapsulates gas molecules such as hydrogen which are stabilized by weak van der Waals forces. This unique cage-guest interaction offers the potential for a safe, economical, and green medium for hydrogen storage. In this study, we use Density Functional Theory (DFT) to investigate the storage capacity of hydrates which primarily depends on the hydrogen occupancy in the small and large cages of the lattice structure. Energy analysis of the system with various occupancies shows that DFT is indicating occupancy limits beyond what has been previously reported and that the maximum occupancy in small and large cages is interdependent. The maximum hydrogen occupancy is 9 in large cages with an occupancy of 1 and 2 in the small cages and a maximum of 8 with an occupancy of 3 or 4 in the small cages. The occupancy limit mechanism is the breakage of hydrogen bonds due to cage volume expansion, the diffusion of hydrogen through pentagonal and hexagonal faces in small and large cages, and computational convergence.

Deciphering the Effect of Microstructural Modification in Sodium Alginate-Based Solid Polymer Electrolyte by Unlike Anions.

Microstructure modification in sodium alginate (NaAlg)-based solid polymer electrolytes by the perchlorate (ClO4-) and acetate (CH3COO-) anions of sodium salts has been reported. ClO4- participates in the structure-breaking effect via inter/intramolecular hydrogen bond breaking, while CH3COO- changes the amorphous phase, as evident from X-ray diffraction studies. The larger size and negative charge delocalization of ClO4- have a plasticizing effect, resulting in a lower glass transition temperature (Tg) compared to CH3COO-. Decomposition temperature is strongly dependent on the type of anion. Scanning electron microscopy images showed divergent modifications in the surface morphology in both electrolyte systems, with variations in salt content. The mechanical properties of the NaAlg-NaClO4 electrolyte systems are better than those of the NaAlg-CH3 COONa system, indicating weak interactions in the latter. Although most of the studies focus on the cation influence on conductivity, the interaction of the anion and its size certainly have an influence on the properties of solid polymer electrolytes, which will be of interest in the near future for sodium ion-based electrolytes in energy storage devices.

Thermodynamic hydration behaviour of glycine below room conditions using time domain reflectometry

The present work reports the concentration-dependent hydrophobicity of glycine below room temperature. The dynamics of aqueous glycine have been studied by means of dielectric relaxation spectroscopy using Time Domain Reflectometry (TDR) technique in the frequency region of 10 MHz–30 GHz. Complex permittivity spectra are obtained using TDR that allowed evaluation of the static dielectric constant (ε0) and average relaxation time (τ). As dielectric relaxation spectroscopy provides information on the average relaxation time (τ) related to the mechanism of hydrogen bond (HB) formation and breaking, therefore the concentration-temperature dependence of τ was used to evaluate and study hydration behaviour through dielectric parameters such as dipole moment (μ), correlation factor (g), and the dynamics of irrationally bound water molecules (Zib). Aqueous glycine relaxes in two different relaxation modes in the broad microwave frequency region from MHz to GHz. The low-frequency relaxation process (l-process) observed is associated with glycine relaxation, while the detected peak in the high-frequency relaxation process (h-process) is attributed to water associated with glycine. We have attempted a concentration-temperature-dependent hydrogen bonding mechanism in both relaxation processes, and the results were corroborated with thermodynamical parameters such as molar entropy of activation (∆Sj), molar enthalpy of activation (∆Hj), and molar free energy of activation (∆Fj).

Curcumin-loaded Pickering emulsion stabilized by pH-induced self-aggregated chitosan particles: Effects of degree of deacetylation and molecular weight

Curcumin, a natural polyphenolic compound, has many health benefits: instabilities and poor solubility limit curcumin's industrial applications. The encapsulation of curcumin in Pickering emulsion can enhance its bioavailability. Developing an efficient and simple method for fabricating a natural emulsifier for Pickering emulsion remains a significant challenge. Chitosan has gained attention for its nontoxicity and excellent emulsifying properties. The purpose of this study was to prepare four different types of self-aggregated chitosan particles using a pH-responsive self-assembling method. The aggregated particle properties are tuned by pH, degree of deacetylation (DDA), and molecular weight (MW) through control of surface charge, size (nano, micro, and floc), and contact angle. Pickering emulsions were prepared using different types of aggregated particles. As MW and pH increase and DDA decreases, aggregated particles networked structures formed, resulting in highly elastic gels more resistant to the breakdown of Pickering emulsion at ambient temperature. When ramped up to higher temperatures, the kinetic energy of aggregated particles increases, disrupting hydrogen bonds and potentially changing the systems from fluids to gels. The aggregated particles-based Pickering emulsion was used as the carrier for curcumin encapsulation. MW and DDA regulate drug loading, encapsulation efficiency, and release profile. It found that DDA and MW were responsible for tuning the properties of Pickering emulsion. This research provides a new perspective on selecting suitable chitosan for controlling the release of bioactive compounds in Pickering emulsions, considering factors such as adjustable rheological properties, microstructure, and macrostructure.

The Molecular Ocean

We report on progress in observing the hydrogen-bonded structure of water and sea water by deep-ocean Raman spectroscopy. In the normal ocean, the abundance of single H2O species is less than 20%. The principal form is the tetrahedral pentamer, and the (H2O)[Formula: see text] nH2O equilibrium plays a dominant role in controlling physicochemical processes and the speed of sound. The enthalpy of the H-bond in water is 2.624 kcal/mol, and in sea water 2.258 kcal/mol due to the quantity of non-HB water in the solvation shell of sea salt ions. The activation energy of viscous flow is 4.28 kcal/mol at one atmosphere pressure, consistent with the need to break hydrogen bonds and overcome the van der Waals intermolecular forces. The activation energy decreases exponentially with depth/pressure and is 10% less at 4,000 m depth. We suggest this is due to the pressure-induced shift in the water equilibrium to favor the less compressible quasi-planar pentamer, tetramer, and so on forms. We address the long-standing conclusion that microbial swimming by means of rotating flagella is only 1%–2% efficient. This neglects the need for microbes to overcome the activation energy of viscous flow; [Formula: see text]95% of the mechanical energy produced by the flagella must be used to break H-bonds and overcome intermolecular forces.

Channel Gating in Kalium Channelrhodopsin Slow Mutants

Kalium channelrhodopsin 1 from Hyphochytrium catenoides (HcKCR1) is the first discovered natural light-gated ion channel that shows higher selectivity to K+ than to Na+ and therefore is used to silence neurons with light (optogenetics). Replacement of the conserved cysteine residue in the transmembrane helix 3 (Cys110) with alanine or threonine results in a >1,000-fold decrease in the channel closing rate. The phenotype of the corresponding mutants in channelrhodopsin 2 is attributed to breaking of a specific interhelical hydrogen bond (the “DC gate”). Unlike CrChR2 and other ChRs with long distance “DC gates”, the HcKCR1 structure does not reveal any hydrogen bonding partners to Cys110, indicating that the mutant phenotype is likely caused by disruption of direct interaction between this residue and the chromophore. In HcKCR1_C110A, fast photochemical conversions corresponding to channel gating were followed by dramatically slower absorption changes. Full recovery of the unphotolyzed state in HcKCR1_C110A was extremely slow with two time constants 5.2 and 70 min. Analysis of the light-minus-dark difference spectra during these slow processes revealed accumulation of at least four spectrally distinct blue light-absorbing photocycle intermediates, L, M1 and M2, and a UV light-absorbing form, typical of bacteriorhodopsin-like channelrhodopsins from cryptophytes. Our results contribute to better understanding of the mechanistic links between the chromophore photochemistry and channel conductance, and provide the basis for using HcKCR1_C110A as an optogenetic tool.

Experimental investigation of evaporation characteristics of sessile fuel droplets on a hot surface

Spilled fuel that comes in contact with hot surfaces can cause a fire, and to mitigate this type of fire, we researched the evaporation patterns and heat transfer mechanisms of fuel droplets on such surfaces. Glass heating substrates were used to experimentally investigate the evaporation behavior of acetic acid, ethanol, acetone, ethyl acetate, n-heptane, and cyclohexane. Infrared imaging technology and volume estimation method were used for the experimental analysis. The study revealed various thermal patterns on the surfaces of different droplets. Hydrothermal waves (HTWs), Bénard-Marangoni (B-M) cells, cyclic thermal patterns, and double-vortex thermal patterns were observed on different types of fuel droplet surfaces. The energy absorption and breakage of intermolecular hydrogen bonds are related to the formation of HTWs and B-M cells. As the height of the droplets decreased, the rate at which the six fuel droplets evaporated was observed to decrease initially and then increase. The results of this experiment indicate that the evaporation rate of droplets is largely determined by the saturation vapor pressure.

Scott Blair Fractional-Type Viscoelastic Behavior of Thermoplastic Polyurethane.

In this paper, the experimental characterization of the viscoelastic properties of thermoplastic polyurethane (TPU) samples through creep experiments is presented. Experiments were conducted at different constant temperature levels (15, 25, and 35 ∘C), for three different tensile stress levels (0.3, 0.5, and 0.7 MPa), and at different physisorbed water contents, providing access to: (i) the temperature dependency of creep parameters and (ii) the assessment, if behavior is indeed viscoelastic. The physisorbed water content was achieved by exposing virgin samples to environments with relative humidity ranging from 0 to 80 percent until mass stability was reached. Creep tests were conducted immediately afterwards with this particular humidity level. The main results of this study are as follows. The temperature dependency of the obtained creep parameters is well described in Arrhenius plots. With regard to water content, two prototype material responses were observed in the experimental program and accurately modeled using the following fractional-type models: (i) Scott Blair-type (i.e., power-law-type) only behavior, pronounced for the combination of low water content/low temperature; (ii) combined Scott Blair plus Lomnitz (i.e., log-type) behavior for high water content/high temperature. This change in behavior associated with certain thresholds for the specified environmental conditions (temperature and relative humidity) may indicate the initiation of hydrogen bond breakage and rearrangement (carbamate H-bonds and physisorbed water H-bonds). Regarding the short-term or quasi-instantaneous behavior, the Scott Blair element seems highly appropriate and may be better suited than the standard elastic model: the Hookean spring. We associated Scott Blair behavior with the load-induced, quasi-instantaneous re-arrangement of polymer network chains. The secondary viscoelastic mechanism associated with the Lomnitz element, hydrogen bond breakage and rearrangement, comes into play for higher temperatures and/or higher physisorbed water contents. In this case, the contribution of the two constitutive elements is well separated due to the large number of the characteristic time of the Lomnitz element, much larger than the respective value for the Scott Blair element.

Utilizing the Hofmeister Effect to Induce Hydrogelation of Nonionic Supramolecular Polymers into a Therapeutic Depot.

Nonionic hydrogels are of particular interest for long-term therapeutic implantation due to their minimal immunogenicity relative to their charged counterparts. However, in situ formation of nonionic supramolecular hydrogels under physiological conditions has been a challenging task. In this context, we report on our discovery of salt-triggered hydrogelation of nonionic supramolecular polymers (SPs) formed by self-assembling prodrug hydrogelators (SAPHs) through the Hofmeister effect. The designed SAPHs consist of two SN-38 units, which is an active metabolite of the anticancer drug irinotecan, and a short peptide grafted with two or four oligoethylene glycol (OEG) segments. Upon self-assembly in water, the resultant nonionic SPs can be triggered to gel upon addition of phosphate salts. Our 1 H NMR studies revealed that the added phosphates led to a change in the chemical shift of the methylene protons, suggestive of a disruption of the water-ether hydrogen bonds and consequent reorganization of the hydration shell surrounding the SPs. This deshielding effect, commensurate with the amount of salt added, likely promoted associative interactions among the SAPH filaments to percolate into a 3D network. The formed hydrogels exhibited a sustained release profile of SN-38 hydrogelator that acted potently against cancer cells.

Effect of supercritical CO2 transient high-pressure fracturing on bituminous coal microstructure

Carbon dioxide phase change fracturing is an effective permeability enhancement technology, and its influence mechanism on the coal microstructure remains to be further investigated. To explore the impact of CO2 fracturing on the coal chemical structure, the self-developed transient high-pressure fracturing of CO2 test platform was independently developed. Based on X-ray photoelectron spectrometer (XPS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), the elemental morphology, functional group and crystal structure of the two bituminous coal samples before and after fracturing were analyzed. The results showed that the fracturing process resulted in the disruption of hydrogen bonds within coal, leading to a reduction in the cross-linking density of the coal structure. Moreover, it facilitated the breaking of fatty alkyl side chains and oxygen-containing functional groups, causing the detachment of side chains and shortening of the fatty chains. The interlayer spacing of aromatic layers (d200) of fractured coal decreased, and the average transverse dimension (La), the average stack height (Lc) and the aromaticity (fa) increased. With the improvement of aromaticity, the arrangement between aromatic layers was looser. The volume and basic unit structure of coal crystal nucleus became larger, and the flattening degree increased. The research results contribute to the understanding of the change of coal microstructure under supercritical CO2 transient high-pressure fracturing and provide theoretical support for exploring the methane adsorption capacity of fractured coal.

Crystallization and vitrification of solutions with weak intermolecular interaction of the components

An experimental study of the phenomenon of cluster crystallization and vitrification of solutions with weak intermolecular interaction of the components was performed with use of a purposely developed method of microvolumetric scanning tensodilatometry. Volumetric effects accompanying cooling and subsequent heating of aqueous solutions of glycerol and dimethyl sulfoxide were recorded within temperature range 300…135 K, and they are completely in line with patterns of cluster crystallization. The same phenomenon was used to analyze the structure of amorphous fractions of such solutions. Formation inside of them of ice nanocrystals without breakage of hydrogen bonds between water molecules and molecules of cryoprotectant dramatically reduces stability of amorphous fractions. Based on the resulted tensodilatograms, state diagrams for solutions, which include cluster phase, were for the first time plotted.

SERS evidence of urea‐disordered G‐quadruplex structure

AbstractStructural changes of the human telomeric d(TTAGGG)4 sequence (Tel24) in the presence of sodium ions and urea were studied using SERS spectroscopy. The SERS spectra indicated that Tel24 (4 × 10−5 mol/l) formed an anti‐parallel G‐quadruplex in a medium containing Na+ ions (100 mmol/l), which was disrupted by the subsequent addition of urea (7.2 mol/l). Intensity ratios of SERS bands originating from breathing vibrations of adenine (~730 cm−1) and guanine (~660 cm−1) rings clearly pointed to the urea‐induced unfolding of G‐quadruplex. In addition, SERS bands assigned to guanine implied the breaking of Hoogsteen hydrogen bonds, most likely due to the bonding of guanine bases with the urea molecules. Considering various experimental conditions applied, the structure‐related SERS response was more pronounced in the silver than in the gold colloid as well as upon NIR (785 nm) rather than Vis (532 nm) laser excitation. The CD spectra of the same colloidal samples supported structural changes of Tel24 obtained by SERS.

Oscillating electric field-induced water blocking breakthrough to facilitate CO2 miscible flooding

CO2 miscible flooding is a great promising enhanced oil recovery (EOR) method. However, the loss of fracturing fluid in the formation causes water blocking that seriously impedes the realisation of CO2 miscible flooding. To solve this problem, a strategy of applying an oscillating electric field to promote CO2 breaking through water blocking and enhance the miscibility of CO2 and oil is proposed. The electric field with the frequency of 12 THz can maximise the breakthrough efficiency of water blocking, while the 16 THz electric field is most conducive to the miscibility of CO2 and oil. Under the 12 THz oscillating electric field, the prompt destruction of the local hydrogen bonds in water blocking results in the fastest breakthrough of water blocking. However, the expansion of water blocking hinders the miscibility of CO2 and oil to some extent. 16 THz oscillating electric field can induce the electric resonance of hydrogen bonds between water molecules, uniformly breaking hydrogen bonds to the greatest extent. Compared to that under the 12 THz electric field, the miscibility of CO2 and oil under the 16 THz electric field is enhanced due to the reduced expansion of water blocking.

Numerical simulation on tar cracking behavior under the Brown’s Gas atmosphere

The Chemkin® calculation software platform was used in this paper, using benzene, toluene, and phenol as tar model compounds, and the cracking law of Brown’s gas to tar model compounds was studied by sensitivity analysis at the temperature of 892.5 K and 1130.5 K, respectively. The results showed that the active free radicals of -H and -O in Brown’s gas promote the breaking of methyl bonds and hydrogen bonds, and the formation of phenoxy ions. With the increasing temperature, the secondary products also promote the tar components cracking. Brown’s gas plays an obvious catalytic role in tar cracking, reducing the activation energy of the reaction, and resulting in a decrease in cracking reaction temperature. In addition to active free radicals of Brown’s gas involved in tar cracking, the phenoxy ions also indirectly affect the tar cracking rate.

G-C3N4 sheet nanoarchitectonics with island-like crystalline/amorphous homojunctions towards efficient H2 and H2O2 evolution

Photocatalystic evolution of H2O2 from water and oxygen has attracted significant attention because of environmentally friendly. The absorption in visible and hydrophilic feature of graphitic carbon nitride (g-C3N4) make it a good candidate. In this paper, a rapid post-treatment at high temperature was developed to obtain g-C3N4 nanosheets with abundant crystalline/amorphous interfaces to form homojunctions, which optimized uniplanar carrier mobility dynamics. The conversion from bulk to two-dimensional g-C3N4 resulted from the breakage of interplanar hydrogen bonds and interlayer Van der Waals force. The unique morphology not only rendered photocatalyst with larger specific surface area but also inhibited the robust volume recombination of charge carriers. The accelerated charge carriers flow at the interface, interplane and interlayer together ameliorated the separation and transfer of electrons and holes. A new-emerged n→π* transition ameliorated the poor light utilization efficiency. Beyond the increased photocatalytic H2 evolution property (779.2 μmol g−1 h−1), optimized sample displayed a H2O2 evolution activity as high as 4877.1 μM g−1 h−1 under visible light illumination, which was ∼5.8 times of that of bulk g-C3N4. Detailed photocatalytic mechanism investigation manifested that the two-step single-electron oxygen reduction process occupied the dominant status in H2O2 evolution. This work proposed a novel strategy for obtaining g-C3N4 homojunctions as a promising bi-functional metal-free catalyst to be applied in clean energy production field.

Degradation of GFRP bars in alkaline environments: An experimental and molecular dynamics study

Glass fibre reinforced polymer (GFRP) bars are widely used as a replacement for reinforced bars due to their high strength-to-weight ratio, whereas they also show a high safety risk for corrosion potential from alkaline ions attack in concrete. In this study, the mechanical property evolution and degradation mechanism of GFRP bars in alkaline environments was studied by using experimental and molecular dynamics simulations. The results show that the decreased strength of the GFRP was mainly associated with the increase in the hydroxide concentration (COH-) in the corrosive solution rather than other ions. The tensile strength of the GFRP bars declined by approximately 10% after 300 days of exposure when the pH of the corrosion solution approached 13. When the pH barely reached 10, the resin-fibre interlaminar shear strength slumped by approximately 29%. The favorable hydrogen bonding network was disrupted by alkaline ions, resulting in a lower interaction energy between water molecules and epoxy resin chain segments. In addition, OH− was distributed around the ester bond and attacked the ester group, and finally, the ester bond was hydrolysed to form carboxylate and alcohol. Free sodium ions combine rapidly with oxygen lone electrons (Na-Ow), thereby accelerating water-resin debonding aging by breaking hydrogen bonds within the polymer network. The hydroxyl radicals further invade the fibres through the microcracks formed inside the resin, causing localized etching of the fibres. The study will provide a theoretical basis for the design of anti-corrosion modification of GFRP bars.

Effect of temperature on the dipole response, structural and dynamical properties of water under external electric fields

Water, as simultaneously the most intriguing and ubiquitous liquid on the planet, holds central relevance in our world – and displays a suite of fascinating anomalies. Of notable interest in this study is the leveraging of non-equilibrium molecular dynamics (NEMD) simulation to study the response of water molecules under the influence of external electric-fields while subjected to temperature changes. In particular, external static and oscillating electric fields with varying (r.m.s) intensities 0.05V/Å and 0.10V/Å and oscillating-field frequencies 50, 100 and 200GHz were examined to gauge the influence of supercooled and nearer-ambient temperature regions on water structure and interaction, dynamical properties, dipolar response, hydrogen-bond kinetics and lifetime. Interestingly, the impact of heating the system was accentuated with increase in the hydrogen-bond lengths, and A–D–H angles while the number of hydrogen-bonds reduced with increase in the temperature for all the fields conditions, although slight variations were observed under the influence of static and oscillating fields. Furthermore, as temperature increases, the increased rate of hydrogen-bond breakage influenced the rapid decay of hydrogen-bond lifetimes for zero- and static-field conditions, while molecular rotations caused by dipole-alignment response to the oscillating fields enhanced to a greater extent the mobility of the molecules, and also increased the rate of hydrogen-bond breakage and diffusivity due to the increased thermal motion. Moreover, the effect of increasing the temperature on the polarisation properties of the liquid weakened the hydrogen-bond network and also led to a decrease in the molecular and time response of the system’s dipole moment; higher temperature and field intensity invoked more rapid system dipolar alignment, in addition to the frequency relating to longer periods and greater intensity. With increasing temperature, the behaviour of system dynamics revealed shorter correlation times for zero-field conditions while oscillating-field with increased intensity revealed more rapid autocorrelation decay in comparison to those with reduced intensity. Indeed, the presence of much longer correlation time manifested by zero-field conditions in the supercooled temperature region evinced succinctly the lack of rotational motion that allows for more rapid decay time.