Bound Water Molecules Research Articles

Water sorption modeling and monolayer of biological and food materials

Despite water molecules are strongly hydrogen bonding to hydrophilic solids, the Brunauer-Emmet-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) surface adsorption models have been widely accepted to describe water sorption properties of biological and food materials. These mathematically quite similar models use parameters which include a theoretical ‘monolayer’ value and one or two other parameters which describe ‘surface affinity’ in thermodynamic terms as heat of sorption. A high surface affinity indicates a strong surface binding of water molecules and preferential monolayer adsorption prior to multilayer sorption. Conversely, biological materials are water plasticized and suffer physicochemical changes at various stages of water sorption. Dynamic water sorption measurements often show regions where time-dependent changes in material characteristics, such as viscous flow and crystallization, may occur as a result of the glass transition. The two or three parameters of the BET and GAB models, respectively, are useful in the analysis of water sorption characteristics of individual substances, although the existence of a monolayer particularly in multicomponent materials may not be justified. Fitting the models to experimental data may occur rather for empirical than theoretical reasons.

Coupled Computational and Laboratory Investigations of Interface Interactions between Binary Polymers, Hydroxypropyl Guar, and Potassium Formate for Crosslinked Hydraulic Fracturing Fluids

Summary Guar gum is an economically and environmentally important material. However, reduced rheological properties of hydroxypropyl guar (HPG) in saline conditions of potassium formate (PF) impeded its hydraulic fracturing (HF) applications. In this study, we coupled molecular dynamics simulation and bench experiments to design binary polymers that can be used to mitigate the reduced viscosity of the HPG-PF system and investigate the relevant physiochemical processes in the fluid. The modeling showed that binary polymer P(AM-AA) with acrylamide (AM) and acrylic acid (AA) monomers had the highest ability to bind water molecules in the HPG-PF solution among four representative binary polymers. Multiple analyses showed that adding P(AM-AA) decreased the number of formate ions around the HPG molecules, bonded with the HPG molecule through hydrogen bonds, and mitigated the coiling of the HPG molecular chain in PF solutions. Further experiments and characterization at the macro- and microscale showed that adding P(AM-AA) indeed improved the viscosity, microrheology, viscoelasticity, and thermal tolerance [>120°C (248°F)] of the HPG-PF solution (1.47 g/cm3) and its associated gel system. Our study indicates the potential application of HPG-PF-P(AM-AA) weighting crosslinked HF fluids (HFFs) for wells with stringent wellbore pressure constraints. It also highlights the significant role of binary polymers in enhancing rheological properties in gel-based crosslinked HFF and addressing complex fluid interface interactions through molecular dynamics simulations.

New insights into hydration shells in boosting marine uranium adsorption kinetics

Identifying mass transfer is essential for boosting adsorption kinetics. The internal and external diffusions serve as rate-limiting steps. The liquid film diffusion is commonly identified as external diffusion, while the mass diffusion across the ubiquitous hydration shell is generally ignored. Charged functional groups can bind water molecules strongly via electrostatically induced hydration. Herein, three representative polar polymers, including cation polymer (PDMAPAA), anion polymer (PSS) and zwitterion polymer (PSBMA), are crosslinked with polyamioxime (PAO) to synthesize radially aligned PAO-PDMAPAA, PAO-PSS, PAO-PSBMA, respectively, by a bidirectional freeze-casting. We focus on the effect of hydration structure and hydration dynamics on marine uranium extraction performance. It is found that the external diffusion in PAO-polar polymer adsorbents can be facilitated due to fast water exchange in dynamic hydration shell, leading to a reduced adsorption equilibrium time compared with the pristine PAO. However, the high hydration degree causes strong viscous shear and high dehydration barrier, which impede the complexation of UO22+ with binding sites of PAO. Although the hydration degree follows the order of PAO-PSBMA > PAO-PDMAPAA > PAO-PSS, PAO-PDMAPAA delivers the shortest equilibrium time required. In addition, the increasing temperature would weaken viscous shear in static hydration shell, which equivalently reduces the apparent friction of hydrated uranyl ions. Consequently, light-irradiated GO@PAO-PDMAPAA adsorbent, in which GO acts as a photothermal mediator, yields a shorter equilibrium time (∼18 days) than PAO-PDMAPAA together with a high uranium adsorption capacity of 12.24 mg-U/g-Ads in natural seawater. These findings provide valuable guidance for enhancing uranium adsorption kinetics associated with hydration shell.

Effects of dextran molecular weight on starch retrogradation and technological properties of Chinese steamed bread: Based on the rubber/glass transition

From the perspective of rubber/glass transition, this study clarified that the impact of dextran on retarding hardening behavior and slowing starch retrogradation of Chinese Steamed Bread (CSB) depended on its molecular weight and concentration level. Guggenheim-Anderson-de Boer (GAB) model was fitted to explore critical behavior changes in rubber/glass transition of CSB. Incorporation of high molecular weight dextran enhanced the elasticity of dough and porosity of CSB, reduced the aging and hardening degree of CSB at appropriate addition levels. CSB hardness showed a growing tendency during storage, while macromolecular dextran reduced the hardness and retrogradation degree by 22.87 % and 67.53 %. Dextran with high molecular weights lowered the glass transition temperature (Tg) and improved the moisture sorption and molecular mobility of CSB under various relative humidity (RHs) conditions by providing hydrophilic sites or intermolecular space to bind water molecules. Meanwhile, it reinforced the binding between denatured gluten and gelatinized starch. Both of them devoted to starch retrogradation inhibition and stable quality maintenance of CSB. CSB is suggested to maintain stable quality at room temperature with RHs ≤33 % to prevent rubber/glass transition. This work provided theoretical guidance for fractionation application of dextran to regulate the quality and extend the shelf-life of flour products.

Understanding the Roles of Excipients in Moisture Management in Solid Dosage Forms.

Excipients are ubiquitous in pharmaceutical products, and often, they can also play a critical role in maintaining product quality. For a product containing a moisture-sensitive drug, moisture can be deleterious to the product stability during storage. Therefore, using excipients that interact with moisture in situ can potentially alleviate product stability issues. In this study, the interactive behavior of starch with moisture was augmented by coprocessing maize starch with sodium chloride (NaCl) or magnesium nitrate hexahydrate [Mg(NO3)2·6H2O] at different concentrations (5 and 10%, w/w). The effect of the formulation on drug stability was assessed through the degradation of acetylsalicylic acid, which was used as the model drug. The results showed that coprocessing of the starch with either NaCl or Mg(NO3)2·6H2O impacted the number of water molecule binding sites on the starch and how the sorbed moisture was distributed. The coprocessed excipients also resulted in lower drug degradation and lesser changes in tablet tensile strength during post-compaction storage. However, corresponding tablet formulations containing physical mixtures of starch and salts did not yield promising outcomes. This study demonstrated the advantageous concomitant use of common excipients by coprocessing to synergistically mitigate the adverse effects of moisture and promote product stability when formulating a moisture-sensitive drug. In addition, the findings could help to improve the understanding of moisture-excipient interactions and allow for the judicious choice of excipients when designing formulations containing moisture-sensitive drugs.

Co-Solutes Induced Changes in the Properties of Polymeric Solution and Water Dynamics.

In this paper we are addressing the co-solute-induced changes in the properties of an aqueous solution of a block copolymer. Due to the preferential interaction of different co-solute with different regions of the block copolymer, the changes were observed in both the physical properties and water dynamics. The modulation of both the physical properties and water dynamics was monitored using different spectroscopic techniques. Different co-solutes affect micellar properties of copolymer to a different extent signifying their interactions with different regions within the copolymer. The solvent relaxation dynamics were also modulated with the additions of different co-solutes. The change in free-energy (ΔGbf) and rate constant for bound to free water interconversion (kbf) in a copolymeric micelle was calculated which gets affected by the addition of co-solutes. The calculated kbf suggests that betaine, sarcosine, TMAO, and GnHCl favor the ordering of water molecules around the micelle and are excluded from the micellar surface whereas, urea favors the formation of free-water molecules rather than the structurally ordered bound water molecules around the micelle by accumulating at the micellar surface. Among the added methylamines trimethylamine N-oxide affected the water dynamics and its kinetics most profoundly. The protective property of GnHCl was revealed.

Trapped Water on Silicates in the Laboratory and in Astrophysical Environments

The existence of strongly bound water molecules on silicate surfaces, above the desorption temperature of water ice, was first predicted by computational studies and has recently been demonstrated by laboratory experiments. Such trapped water may be present in various astrophysical environments and there is now evidence for its presence in the diffuse interstellar medium (ISM) and in extraterrestrial particles. We present here new results of a laboratory study of the phenomenon of trapping (strong bonding) of water molecules by silicates. We show that the efficiency of the trapping is strongly dependent on the properties and composition of the surface. Our results point out that the presence of trapped water should be due to the hydrophilic properties of the silicate surface and that the nature of the trapping is physical (physisorption rather than chemisorption). We demonstrate that water can be trapped on silicates up to temperatures of about 470 K, which speaks for the presence of wet silicate grains in the terrestrial planet formation zone in planet-forming disks. Studying the thermal and UV stability of trapped water, we conclude that the detection of trapped water in the diffuse ISM speaks for its efficient continuous formation. We discuss our results as relevant to fundamental scientific questions, such as the oxygen depletion problem, the origin of water on Earth, and the formation of rocky planets.

Preparation and Application of Zwitterion Modified Starch Catalyzed by HRP‐ACAC Binary System

AbstractEnzymatic modification, compared with traditional starch (St) chemical modification methods, avoids using toxic solvents and toxic catalysts. The horseradish peroxidase (HRP), being the most commonly employed natural green initiator, has found extensive application in starch grafting modification as a substitute for chemical initiators. HRP‐catalyzed grafting of starch with vinyl zwitterionic monomers has not been reported. Here, modified starch (St‐PSBMA) is first synthesized by grafting zwitterionic sulfobetaine [2‐(Methacryloyloxy)ethyl]dimethyl‐(3‐sulfopropyl) (SBMA) onto starch by HRP/Acetylacetone(ACAC) binary initiation system catalyzed. The modified starch‐based hydrogel is then prepared by the repeated freeze‐thaw method. Compared with native starch‐based hydrogels, which bind water molecules only through hydrogen bonding, the ability of modified starch‐based hydrogels to bind water molecules is enhanced by ionic solvation. The modified starch hydrogels also have excellent antiprotein adsorption and antibacterial properties due to the presence of a strong hydration layer. The modified starch‐based hydrogel also has excellent sensitivity and stability when used as a sensor for detecting joint motion. The binary HRP initiating system, employed in this study instead of the traditional three‐component HRP initiating system, offers a novel and promising approach for grafting modification of starch without the need for strong oxidant hydrogen peroxide.

Enhanced separation via confined shear flow in microchannel: A novel insight into the role of confined hydrogen bonds in microfluid and its effect on competitive mass transfer of hydrated ions

Microfluidic extraction and separation have demonstrated enormous potential in the field of purification and separation, but the essence of its enhanced separation has always been a focus of debate in the academic community. This study reveals that the interaction between extractant molecules and ions in the process of microfluidic extraction exhibits some significant differences from conventional liquid–liquid two phase stirring dispersed droplet extraction. The interaction between extractant molecules and metal ions through the hydrogen bonds (H-bonds) bridged by water molecules around the hydration shell of metal ions exhibits a noticeable change in confined flow in microchannel. It was demonstrated that in our experiments that the strength difference of this interaction is subjected to the ability of different metal ions to bind water molecules. Therefore, the differences in the interaction between extractant molecules and ions through the hydrogen bonding “water-bridge” are easier to be distinguished within the confined fluid, due to the different effects from the confined environment on mass transfer of metal ions with different abilities to bind water molecules. The confined fluid environment strengthened the difference in the interaction, leading to an amplification of difference in ion diffusion rates, thereby achieving enhanced separation of target rare earth Er3+ ions from the coexisting background ions. Hydrophilic coexisting background ions can be separated by reducing the microchannel width, so that the βEr/Al increases from 2.95 to 49.78. However, the relatively hydrophobic background ions can be separated by increasing flow rates, so that the βEr/Mg increases from 75.32 to 299.06. This work provides a new insight into the essence of microfluidic enhanced separation from the perspective of confined H-bonds.

Reversibility in the Physical Properties of Agarose Gels following an Exchange in Solvent and Non-Solvent.

Agarose forms a homogeneous thermoreversible gel in an aqueous solvent above a critical polymer concentration. Contrary to the prevailing consensus, recent confirmations indicate that agarose gels are also stable in non-solvents like acetone and ethanol. A previous study compared gel characterisations and behaviours in water and ethanol, discussing the gelation mechanism. In the current work, the ethanol gel is exchanged with water to explore the potential reversibility of the displacement of water in agarose. Initially, the structure is characterised using 1H NMR in DMSO-d6 and D2O solvents. Subsequently, a very low yield (0.04) of methyl substitution per agarobiose unit is determined. The different gels after stabilisation are characterised using rheology, and their physical properties are compared based on the solvent used. The bound water molecules, acting as plasticizers in aqueous medium, are likely removed during the exchange process with ethanol, resulting in a stronger and more fragile gel. Next, the gel obtained after the second exchange from ethanol back to water is compared with the initial gel prepared in water. This is the first time where such gel has been characterised without undergoing a phase transition when switching from a good solvent to a non-solvent, and vice versa, thereby testing the reversibility of the solvent exchange. Reversibility of this behaviour is demonstrated through swelling and rheology experiments. This study extends the application of agarose in chromatography and electrophoresis.

Structurally Dynamic Monocyte-Liposome Hybrid Vesicles as an Anticancer Drug Delivery Vehicle: A Crucial Correlation of Microscopic Elasticity and Ultrafast Dynamics.

A biomimetic cell-based carrier system based on monocyte membranes and liposomes has been designed to create a hybrid "Monocyte-LP" which inherits the surface antigens of the monocytes along with the drug encapsulation property of the liposome. Förster resonance energy transfer (FRET) and polarization gated anisotropy measurements show the stiffness of the vesicles obtained from monocyte membranes (Mons), phosphatidylcholine membranes (LP), and Monocyte-LP to follow an increasing order of Mons > Monocyte-LP > LP. The dynamics of interface bound water molecules plays a key role in the elasticity of the vesicles, which in turn imparts higher delivery efficacy to the hybrid Monocyte-LP for a model anticancer drug doxorubicin than the other two vesicles, indicating a critical balance between flexibility and rigidity for an efficient cellular uptake. The present work provides insight on the influence of elasticity of delivery vehicles for enhanced drug delivery.

Solvent Effects on Metal-free Covalent Organic Frameworks in Oxygen Reduction Reaction.

Binding water molecules to polar sites in covalent organic frameworks (COFs) is inevitable, but the corresponding solvent effects in electrocatalytic process have been largely overlooked. Herein, we investigate the solvent effects on COFs for catalyzing the oxygen reduction reaction (ORR). Our designed COFs incorporated different kinds of nitrogen atoms (imine N, pyridine N, and phenazine N), enabling tunable interactions with water molecules. These interactions play a crucial role in modulating electronic states and altering the catalytic centers within the COFs. Among the synthesized COFs, the one with pyridine N atoms exhibits the highest activity, with characterized by a half-wave potential of 0.78 V and a mass activity of 0.32 A mg-1, which surpass those from other metal-free COFs. Theoretical calculations further reveal that the enhanced activity can be attributed to the stronger binding ability of *OOH intermediates to the carbon atoms adjacent to the pyridine N sites. This work sheds light on the significance of considering solvent effects on COFs in electrocatalytic systems, providing valuable insights into their design and optimization for improved performance.

Solvent Effects on Metal‐free Covalent Organic Frameworks in Oxygen Reduction Reaction

AbstractBinding water molecules to polar sites in covalent organic frameworks (COFs) is inevitable, but the corresponding solvent effects in electrocatalytic process have been largely overlooked. Herein, we investigate the solvent effects on COFs for catalyzing the oxygen reduction reaction (ORR). Our designed COFs incorporated different kinds of nitrogen atoms (imine N, pyridine N, and phenazine N), enabling tunable interactions with water molecules. These interactions play a crucial role in modulating electronic states and altering the catalytic centers within the COFs. Among the synthesized COFs, the one with pyridine N atoms exhibits the highest activity, with characterized by a half‐wave potential of 0.78 V and a mass activity of 0.32 A mg−1, which surpass those from other metal‐free COFs. Theoretical calculations further reveal that the enhanced activity can be attributed to the stronger binding ability of *OOH intermediates to the carbon atoms adjacent to the pyridine N sites. This work sheds light on the significance of considering solvent effects on COFs in electrocatalytic systems, providing valuable insights into their design and optimization for improved performance.

Preparation and Characterization of PVA/Chitosan-Based Hydrogels Enriched with Carbon Materials via the Freeze-Thaw Method

The freeze-thaw method successfully prepared polyvinyl alcohol (PVA)/chitosan (CS)-based hydrogels. This study evaluated the hydrogel’s physical and thermal properties with a compositional variation of activated carbon (AC) and reduced graphene oxide (rGO) in PVA/CS (PCS) hydrogel. Incorporating AC into the PCS hydrogel led to pore reduction, yielding a lower swelling degree in PCS/AC hydrogel than in PCS hydrogel. On the other hand, adding rGO had minimal impact on the shape and distribution of pores. However, rGO exhibited effective dispersion on the hydrogel surface, reducing the swelling degree of PCS/rGO hydrogel. The maximum swelling degree only showed an increase in PCS/AC 0.1%, attributed to the porous nature of AC, effectively binding water molecules while maintaining a relatively consistent pore size compared to PCS hydrogel. Incorporating AC and rGO into the PCS hydrogel enhanced thermal stability, which is evident from the increased residue and endothermic peak temperature compared to the hydrogel without AC and rGO. These findings suggest that the modification with AC and rGO can enhance the physical and thermal properties of PCS hydrogel.

Adhesion preference of the sticky bacterium Acinetobacter sp. Tol 5.

Gram-negative bacterium Acinetobacter sp. Tol 5 exhibits high adhesiveness to various surfaces of general materials, from hydrophobic plastics to hydrophilic glass and metals, via AtaA, an Acinetobacter trimeric autotransporter adhesin Although the adhesion of Tol 5 is nonspecific, Tol 5 cells may have prefer materials for adhesion. Here, we examined the adhesion of Tol 5 and other bacteria expressing different TAAs to various materials, including antiadhesive surfaces. The results highlighted the stickiness of Tol 5 through the action of AtaA, which enabled Tol 5 cells to adhere even to antiadhesive materials, including polytetrafluoroethylene with a low surface free energy, a hydrophilic polymer brush with steric hindrance, and mica with an ultrasmooth surface. Single-cell force spectroscopy as an atomic force microscopy technique revealed the strong cell adhesion force of Tol 5 to these antiadhesive materials. Nevertheless, Tol 5 cells showed a weak adhesion force toward a zwitterionic 2-methacryloyloxyethyl-phosphorylcholine (MPC) polymer-coated surface. Dynamic flow chamber experiments revealed that Tol 5 cells, once attached to the MPC polymer-coated surface, were exfoliated by weak shear stress. The underlying adhesive mechanism was presumed to involve exchangeable, weakly bound water molecules. Our results will contribute to the understanding and control of cell adhesion of Tol 5 for immobilized bioprocess applications and other TAA-expressing pathogenic bacteria of medical importance.

Diffusion of Water Molecules on the Surface of Silica Nanoparticles─Insights from Nuclear Magnetic Resonance Relaxometry.

1H spin-lattice nuclear magnetic resonance (NMR) relaxation experiments have been performed for water dispersions of functionalized silica nanoparticles of diameters of 25 and 45 nm. The experiments have been performed in a broad frequency range spanning 3 orders of magnitude, from 10 kHz to 10 MHz, versus temperature, from 313 to 263 K. On the basis of the data, two-dimensional translation diffusion (diffusion close to the nanoparticle surface within a layer of the order of a few diameters of water molecules) has been revealed. The translational correlation times as well as the residence life times on the nanoparticle surface have been determined. It has turned out that the residence lifetime is temperature-independent and is on the order of 5 × 10-6 s for the smaller nanoparticles and by about a factor of 3 longer for the larger ones. The translational correlation time for the case of 25 nm nanoparticles is also temperature-independent and yields about 6 × 10-7 s, while for the dispersion of the larger nanoparticles, the correlation times changed from about 8 × 10-7 s at 313 K to about 1.2 × 10-6 s at 263 K. In addition to the quantitative characterization of the two-dimensional translation diffusion, correlation times associated with bound water molecules have been determined. The studies have also given insights into the population of the bound and diffusing water on the surface water fractions.

Preparation of high performance membrane via one-step polymerization and co-deposition of polydopamine/zwitterionic monomers/poly(ethylene glycol) diacrylate

Membrane separation is an effective method for water purification. However, conventional preparation processes for the membranes usually suffer from complicated production technology and lack versatility. Mussel-inspired chemistry has generated extensive interest in exploring a facile strategy for the preparation of polymeric membranes. In this work, a simple, green and time saving strategy is proposed for accomplishing the surface functionalization via one-step polymerization and co-deposition of dopamine/zwitterion/poly(ethylene glycol) diacrylate (PEGDA). The chain segment of the zwitterion can tightly bind water molecules upon the membrane surface, enhancing the hydrophilicity of the membrane. The chain segment of PEGDA can offer cross-linking sites during the co-deposition process, facilitating the formation of the network structure. The retention to dyes for the membranes prepared with PEGDA was higher than those membranes prepared without PEGDA. The optimized membrane exhibited high water permeance up to 25.9 L m−2 h−1 bar−1, with rejection of 99.7 % and 99.6 % for Methyl blue and Congo Red. Meanwhile, the anti-bacterial rate for the optimized membrane reaches 75.9 %, and the water flux recovery rate (FRR) is as high as 86.65 %. The results cast a light on the exploration of the PDA-based NF membranes, featuring simple production technology and versatile capabilities for the separation of various dyes.

Elm wood (Ulmus rubra) vacuum drying at 40 °C studied by time domain nuclear magnetic resonance (TD-NMR)

Abstract The time domain nuclear magnetic resonance (TD-NMR) technique was employed to distinguish various water states, and the moisture migration during Elm wood (Ulmus rubra) heartwood vacuum drying was quantitatively analyzed. The transverse relaxation time (T2) was employed to establish the correlation between drying time and moisture migration. Additionally, the longitudinal relaxation time (T1) was utilized to identify two types of water states within the cell wall: OH bound water (B-water) and more freely bound water (C-water). Meanwhile, the changes in these two types of bound water during the drying were investigated. The results demonstrated an exponential decrease in the content of OH bound water and more freely bound water with drying time. OH bound water within the cell wall predominated, with only a small portion of more freely bound water experiencing migration loss when the moisture content (MC) dropped below 20 %. Furthermore, OH bound water exhibited higher migration rate compared to more freely bound water at 10–20 % MC, while the motion of OH bound water molecules became highly restricted and stronger binding to cell walls than more freely bound water at a MC level of below 10 %. These findings yield a theoretical foundation and empirical support for optimizing drying methods.

Chaotropic Nanoelectrocatalysis: Chemically Disrupting Water Intermolecular Network at the Point‐of‐Catalysis to Boost Green Hydrogen Electrosynthesis

AbstractEfficient green hydrogen production through electrocatalytic water splitting serves as a powerful catalyst for realizing a carbon‐free hydrogen economy. However, current electrocatalytic designs face challenges such as poor hydrogen evolution reaction (HER) performance (Tafel slope, 100–140 mV dec−1) because water molecules are thermodynamically trapped within their extensive hydrogen bonding network. Herein, we drive efficient HER by manipulating the local water microenvironment near the electrocatalyst. This is achieved by functionalizing the nanoelectrocatalyst's surface with a monolayer of chaotropic molecules to chemically weaken water‐water interactions directly at the point‐of‐catalysis. Notably, our chaotropic design demonstrates a superior Tafel slope (77 mV dec−1) and the lowest overpotential (0.3 V at 10 mA cm−2ECSA), surpassing its kosmotropic counterparts (which reinforces the water molecular network) and previously reported electrocatalytic designs by up to ≈2‐fold and ≈3‐fold, respectively. Comprehensive mechanistic investigations highlight the critical role of chaotropic surface chemistry in disrupting the water intermolecular network, thereby releasing free/weakly bound water molecules that strongly interact with the electrocatalyst to boost HER. Our study provides a unique molecular approach that can be readily integrated with emerging electrocatalytic materials to rapidly advance the electrosynthesis of green hydrogen, holding immense promise for sustainable chemical and energy applications.

Chaotropic Nanoelectrocatalysis: Chemically Disrupting Water Intermolecular Network at the Point-of-Catalysis to Boost Green Hydrogen Electrosynthesis.

Efficient green hydrogen production through electrocatalytic water splitting serves as a powerful catalyst for realizing a carbon-free hydrogen economy. However, current electrocatalytic designs face challenges such as poor hydrogen evolution reaction (HER) performance (Tafel slope, 100-140 mV dec-1 ) because water molecules are thermodynamically trapped within their extensive hydrogen bonding network. Herein, we drive efficient HER by manipulating the local water microenvironment near the electrocatalyst. This is achieved by functionalizing the nanoelectrocatalyst's surface with a monolayer of chaotropic molecules to chemically weaken water-water interactions directly at the point-of-catalysis. Notably, our chaotropic design demonstrates a superior Tafel slope (77 mV dec-1 ) and the lowest overpotential (0.3 V at 10 mA cm-2 ECSA ), surpassing its kosmotropic counterparts (which reinforces the water molecular network) and previously reported electrocatalytic designs by up to ≈2-fold and ≈3-fold, respectively. Comprehensive mechanistic investigations highlight the critical role of chaotropic surface chemistry in disrupting the water intermolecular network, thereby releasing free/weakly bound water molecules that strongly interact with the electrocatalyst to boost HER. Our study provides a unique molecular approach that can be readily integrated with emerging electrocatalytic materials to rapidly advance the electrosynthesis of green hydrogen, holding immense promise for sustainable chemical and energy applications.