Water-soluble Polymers Research Articles

Review of advanced cementitious composites using water soluble polymer based admixture

AbstractThis paper offers a thorough unfolding of the many contributions that water‐soluble polymers (WSPs) play in cementitious composites. The several forms of WSPs—natural, semi‐synthetic, and artificial—are examined, and their methods of action in cementitious composites are investigated. The topics of binding, association, adhesion, complexation, and bridge creation are covered in the literature. The effects of WSPs on the microstructure, freshness, mechanical properties, and durability of cement‐based goods are also investigated in this review. The advantages and disadvantages of utilizing WSPs in cement‐based products are also discussed. Following a detailed analysis of the most significant findings, recommendations are made for both academic and practical research areas and applications. This study provides useful information for both experts and novices by elucidating the multi‐applications of WSPs in cementitious materials.

The Effects of Endoplasmic Reticulum Stress via Intratracheal Instillation of Water-Soluble Acrylic Acid Polymer on the Lungs of Rats.

Polyacrylic acid (PAA), an organic chemical, has been used as an intermediate in the manufacture of pharmaceuticals and cosmetics. It has been suggested recently that PAA has a high pulmonary inflammatory and fibrotic potential. Although endoplasmic reticulum stress is induced by various external and intracellular stimuli, there have been no reports examining the relationship between PAA-induced lung injury and endoplasmic reticulum stress. F344 rats were intratracheally instilled with dispersed PAA (molecular weight: 269,000) at low (0.5 mg/mL) and high (2.5 mg/mL) doses, and they were sacrificed at 3 days, 1 week, 1 month, 3 months and 6 months after exposure. PAA caused extensive inflammation and fibrotic changes in the lungs' histopathology over a month following instillation. Compared to the control group, the mRNA levels of endoplasmic reticulum stress markers Bip and Chop in BALF were significantly increased in the exposure group. In fluorescent immunostaining, both Bip and Chop exhibited co-localization with macrophages. Intratracheal instillation of PAA induced neutrophil inflammation and fibrosis in the rat lung, suggesting that PAA with molecular weight 269,000 may lead to pulmonary disorder. Furthermore, the presence of endoplasmic reticulum stress in macrophages was suggested to be involved in PAA-induced lung injury.

Anion Competition at Positively Charged Surfactant Monolayers.

Interactions of anions with hydrophobic surfaces of proteins and water-soluble polymers depend on the ability of the ions to shed their hydration shells. At positively charged surfactant monolayers, the interactions of anions are less well understood. Due to the interplay of electrostatic surface forces, hydration effects, and ion-ion interactions in the electrostatic double layer, a comprehensive microscopic picture remains elusive. Herein, we study the interactions of chloride, bromide, and a mixture of these two anions at the aqueous interface of dihexadecyldimethylammonium (DHDA+) and dioctadecyldimethylammonium (DODA+) cationic monolayers. Using molecular dynamics simulations and three surface-sensitive X-ray scattering techniques, we demonstrate that bromide interacts preferentially over chloride with both monolayers. The structure of the two monolayers and their interfacial electron density profiles obtained from the simulations quantitatively reproduce the experimental data. We observe that chloride and bromide form contact ion pairs with the quaternary ammonium groups on both monolayers. However, ion pairing with bromide leads to a greater reduction in the number of water molecules hydrating the anion, resulting in more energetically stable ion pairs. This leads to long-range (>3 nm) lateral correlations between bromide ions on the structured DODA+ monolayer. These observations indicate that ion hydration is the dominant factor determining the interfacial electrolyte structure.

Effect of water-soluble polymers on the transport of functional group-modified polystyrene nanoplastics in goethite-coated saturated porous media

The research on the impact of water-soluble polymers (WSPs) on the migration and fate of plastic particles is extremely limited. This article explored the effects of polyacrylic acid (PAA, a common WSP) and physicochemical factors on the transport of polystyrene nanoparticles (PSNPs-NH2/COOH) with different functional groups in QS (quartz sand) and FOS (goethite-modified quartz sand, simulates mineral colloids). Research has shown that PAA can selectively adsorb onto the surface of PSNPs-NH2, forming ecological corona heterogeneous aggregates. This process increased the spatial hindrance and elastic repulsion, resulting in the recovery of PSNPs-NH2 always exceeding that of PSNPs-COOH. Overall, PAA can hinder the migration of PSNPs in QS but can promote their migration in FOS. When multivalent cations coexist with PAA, the transport of PSNPs in the media is primarily affected by cation bridging and CH-cation-π interaction. The presence of oxyanions and PAA prevents PSNPs from following the Hofmeister rule and promotes their migration (PO43-: 82.34 ± 0.16% to 94.63 ± 2.82%>SO42-: 81.38 ± 2.73% to 91.15 ± 0.93%>NO3-: 55.85 ± 0.70%−87.16 ± 3.80%). The findings of this study contribute significantly to a better understanding of the migration of WSPs and group-modified NPs in complex saturated porous media.

Unveiling the multilevel impact of four water-soluble polymers on Daphnia magna: From proteome to behaviour (a case study)

The ubiquitous presence of water-soluble polymers (WSPs) in freshwater environments raises concerns regarding potential threats to aquatic organisms. This study investigated, for the first time, the effects of widely used WSPs -polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), and polyethylene glycol (PEG)- using a multi-level approach in the freshwater biological model Daphnia magna. This integrated assessment employed a suite of biomarkers, evaluation of swimming behaviour, and proteomic analysis to investigate the effects of three environmentally relevant concentrations (0.001, 0.5, and 1 mg/L) of the tested WSPs from molecular to organismal levels, assessing both acute and chronic effects. Our findings reveal that exposure to different WSPs induces specific responses at each biological level, with PEG being the only WSP inducing lethal effects at 0.5 mg/L. At the physiological level, although all WSPs impacted both swimming performance and heart rate of D. magna specimens, PAA exhibited the greatest effects on the measured behavioural parameters. Furthermore, proteomic analyses demonstrated altered protein profiles following exposure to all WSPs, with PVA emerging as the most effective.

Facile crosslinking of PVA scaffolds using quercetin for biomaterial applications

Polyvinyl alcohol (PVA) is water soluble and biodegradable polymer known for its biocompatibility, low protein adhesion and minimal toxicity. However, inadequate mechanical stability limits its usage in various biomedical applications. This study explored the usage of quercetin as a promising crosslinking agent for PVA to significantly improve mechanical strength and water resistance. PVA was crosslinked with four concentrations of quercetin in ratios (1:0.005, 1:0.01, 1:0.015, 1:0.02 w/w). Scaffolds of uniform thickness (0.5 mm) were prepared using freeze-drying technique. The crosslinking efficiency and durability of PVA and PVA-quercetin scaffolds were studied based on residual weight ratio upon swelling, thermogravimetric, and Fourier Transform Infrared (FTIR) spectroscopic analysis. Results indicate that PVA-quercetin (1:0.02) showed better crosslinking efficiency with enhanced stability when compared with uncross-linked PVA which was further confirmed by the reduction of solubility in water which is substatiated by lower hydroxyl peak at 3200 cm−1. Further, the present work describes a facile methodology to crosslink PVA for developing a biomaterial with the potential antioxidant ability of quercetin.

Comparing the Kinetic Hydrate Inhibition Performance of Linear versus Branched Polymers.

Kinetic hydrate inhibitors (KHIs) are a chemical method of preventing gas hydrate plugging of oil and gas production flow lines. The main ingredient in a KHI formulation is one or more water-soluble amphiphilic polymers. Poly(N-vinyl caprolactam) (PVCap) is an unbranched polymer and a well-known industrial KHI, often used as a yardstick to compare the performance of new polymers. The effect of branching PVCap on KHI performance has been investigated by polymerizing the VCap monomer in the presence of varying amounts of trimethylolpropane triacrylate, pentaerythritol tetraacrylate, or bis-pentaerythritol hexaacrylate cross-linkers to give PVCap polymers with 3, 4, and 6 branches, respectively. If the ratio of cross-linker to VCap was too high (6:1 to 8:1), gelling and/or poor water solubility was observed, giving short polymer chains and poor KHI efficacy. For higher ratios (30:1 to 60:1), it was found that the concentration of the polymer needed to give total inhibition of structure II tetrahydrofuran hydrate crystal growth could be lowered by using tribranched rather than linear PVCap. Slow constant cooling (1 °C/h) gas hydrate experiments with a synthetic natural gas in steel rocking cells at 76 bar were also carried out. A small improvement in KHI performance was observed for one of the branched PVCaps compared with a linear PVCap. Branched and linear poly(N-isopropylmethacrylamide) (PNIPMAm) polymers were also investigated in the gas hydrate system, but there was no benefit observed when branching this polymer class.

Biodegradable Zwitterionic Polymers as PEG Alternatives for Drug Delivery.

Poly(ethylene glycol) (PEG) is a highly biocompatible and water-soluble polymer that is widely utilized for biomedical applications. Unfortunately, the immunogenicity and antigenicity of PEG severely restrict the biomedical efficacy of pegylated therapeutics. As emerging PEG alternatives, biodegradable zwitterionic polymers (ZPs) have attracted significant interest in recent years. Biodegradable ZPs generally are not only water-soluble and immunologically inert, but also possess a range of favorable biomedically relevant properties, without causing long-term side effects for in vivo biomedical applications. This review presents a systematic overview of recent studies on biodegradable ZPs. Their structural designs and synthetic strategies by integrating biodegradable base polymers with zwitterions are addressed. Their applications in the delivery of small molecule drugs (as mono-drugs or multi-drugs) and proteins are highlighted.

Location of a Hydrophobic Load in Poly(oligo(ethylene glycol) methyl ether methacrylate)s (PEGMAs) Dissolved in Water and Probed by Fluorescence.

Two series of pyrene-labeled poly(oligo(ethylene glycol) methyl ether methacrylate)s referred to as PyEG5-PEGnMA and PyC4-PEGnMA were prepared to probe the region surrounding the polymethacrylate backbone by using the fluorescence of the dye pyrene. PyEG5-PEGnMA and PyC4-PEGnMA were prepared by copolymerizing the EGnMA methacrylate monomers with penta(ethylene glycol) 1-pyrenemethyl ether methacrylate or 1-pyrenebutyl methacrylate, respectively. In organic solvents, the much longer 18 non-hydrogen atom linker connecting the pyrene moieties to the polymethacrylate backbone in the PyEG5-PEGnMA samples enabled the deployment of the pyrenyl labels into the solution. In water, however, an excited pyrene for PyEG5-PEGnMA was found to probe a same volume as for the PyC4-PEGnMA samples where a much shorter 6 non-hydrogen atom spacer connected pyrene to the backbone. Another surprising observation, considering that the hydrophobicity of pyrene induces strong pyrene aggregation for many pyrene-labeled water-soluble polymers (Py-WSPs) in water, was the little pyrene aggregation found for the PyEG5-PEGnMA and PyC4-PEGnMA samples in water. These effects could be related to the organic-like domain (OLD) generated by the oligo(ethylene glycol) side chains densely arranged around the polymethacrylate backbone of the polymeric bottlebrush (PBB). Additional fluorescence experiments conducted with the penta(ethylene glycol) 1-pyrenemethyl ether derivative indicated that the cylindrical OLD surrounding the polymethacrylate backbone had a chemical composition similar to that of ethylene glycol. Binding of hydrophobic pyrene molecules to unlabeled PEGnMA bottlebrushes in water further supported the existence of the OLD. The demonstration, that PEGnMA samples form an OLD in water, which can host and protect hydrophobic cargoes like pyrene, should lead to the development of improved PEGnMA-based drug delivery systems.

Amyloid β-Peptide Segment Conjugated Side-Chain Proline-Based Polymers as Potent Inhibitors in Lysozyme Amyloidosis.

Developing effective amyloidosis inhibitors poses a significant challenge due to the dynamic nature of the protein structures, the complex interplay of interfaces in protein-protein interactions, and the irreversible nature of amyloid assembly. The interactions of amyloidogenic polypeptides with other peptides play a pivotal role in modulating amyloidosis and fibril formation. This study presents a novel approach for designing and synthesizing amyloid interaction surfaces using segments derived from the amyloid-promoting sequence of amyloid β-peptide [VF(Aβ(18-19)/FF(Aβ(19-20)/LVF(Aβ(17-19)/LVFF(Aβ(17-20)], where VF, FF, LVF and LVFF stands for valine phenylalanine dipeptide, phenylalanine phenylalanine dipeptide, leucine valine phenylalanine tripeptide and leucine valine phenylalanine phenylalanine tetrapeptide, respectively. These segments are conjugated with side-chain proline-based methacrylate polymers serving as potent lysozyme amyloidosis inhibitors and demonstrating reduced cytotoxicity of amyloid aggregations. Di-, tri-, and tetra-peptide conjugated chain transfer agents (CTAs) were synthesized and used for the reversible addition-fragmentation chain transfer polymerization of tert-butoxycarbonyl (Boc)-proline methacryloyloxyethyl ester (Boc-Pro-HEMA). Deprotection of Boc-groups from the side-chain proline pendants resulted in water-soluble polymers with defined peptide chain ends as peptide-polymer bioconjugates. Among them, the LVFF-conjugated polymer acted as a potent inhibitor with significantly suppressed lysozyme amyloidosis, a finding supported by comprehensive spectroscopic, microscopic, and computational analyses. These results unveil the synergistic effect between the segment-derived amyloid β-peptide and side-chain proline-based polymers, offering new prospects for targeting lysozyme amyloidosis.

Design of Sustainable Aluminium-Based Feedstocks for Composite Extrusion Modelling (CEM).

Additive manufacturing (AM) has become one of the most promising manufacturing techniques in recent years due to the geometric design freedom that this technology offers. The main objective of this study is to explore Composite Extrusion Modelling (CEM) with aluminium as an alternative processing route for aluminium alloys. This process allows for working with pellets that are deposited directly, layer by layer. The aim of the technique is to obtain aluminium alloy samples for industrial applications with high precision, without defects, and which are processed in an environmentally friendly manner. For this purpose, an initial and preliminary study using powder injection moulding (PIM), necessary for the production of samples, has been carried out. The first challenge was the design of a sustainable aluminium-based feedstock. The powder injection moulding technique was used as a first approach to optimise the properties of the feedstock through a combination of water-soluble polymer, polyethyleneglycol (PEG), and cellulose acetate butyrate (CAB) wich produces low CO2 emissions. To do this, a microstructural characterisation was carried out and the critical solid loading and rheological properties of the feedstocks were studied. Furthermore, the debinding conditions and sintering parameters were adjusted in order to obtain samples with the required density for the following processes and with high geometrical accuracy. In the same way, the printing parameters were optimised for proper material deposition.

Large-Scale, Mechanically Robust, Solvent-Resistant, and Antioxidant MXene-Based Composites for Reliable Long-Term Infrared Stealth.

MXene-based thermal camouflage materials have gained increasing attention due to their low emissivity, however, the poor anti-oxidation restricts their potential applications under complex environments. Various modification methods and strategies, e.g., the addition of antioxidant molecules and fillers have been developed to overcome this, but the realization of long-term, reliable thermal camouflage using MXene network (coating) with excellent comprehensive performance remains a great challenge. Here, a MXene-based hybrid network comodified with hyaluronic acid (HA) and hyperbranched polysiloxane (HSi) molecules is designed and fabricated. Notably, the presence of appreciated HA molecules restricts the oxidation of MXene sheets without altering infrared stealth performance, superior to other water-soluble polymers; while the HSi molecules can act as efficient cross-linking agents to generate strong interactions between MXene sheets and HA molecules. The optimized MXene/HA/HSi composites exhibit excellent mechanical flexibility (folded into crane structure), good water/solvent resistance, and long-term stable thermal camouflage capability (with low infrared emissivity of ≈0.29). The long-term thermal camouflage reliability (≈8 months) under various outdoor weathers and the scalable coating capability of the MXene-coated textile enable them to disguise the IR signal of various targets in complex environments, indicating the great promise of achieved material for thermal camouflage, IR stealth, and counter surveillance.

Low-Viscosity Route to High-Molecular-Weight Water-Soluble Polymers: Exploiting the Salt Sensitivity of Poly(N-acryloylmorpholine).

We report a new one-pot low-viscosity synthetic route to high molecular weight non-ionic water-soluble polymers based on polymerization-induced self-assembly (PISA). The RAFT aqueous dispersion polymerization of N-acryloylmorpholine (NAM) is conducted at 30 °C using a suitable redox initiator and a poly(2-hydroxyethyl acrylamide) (PHEAC) precursor in the presence of 0.60 M ammonium sulfate. This relatively low level of added electrolyte is sufficient to salt out the PNAM block, while steric stabilization is conferred by the relatively short salt-tolerant PHEAC block. A mean degree of polymerization (DP) of up to 6000 was targeted for the PNAM block, and high NAM conversions (>96%) were obtained in all cases. On dilution with deionized water, the as-synthesized sterically stabilized particles undergo dissociation to afford molecularly dissolved chains, as judged by dynamic light scattering and 1H NMR spectroscopy studies. DMF GPC analysis confirmed a high chain extension efficiency for the PHEAC precursor, but relatively broad molecular weight distributions were observed for the PHEAC-PNAM diblock copolymer chains (Mw/Mn > 1.9). This has been observed for many other PISA formulations when targeting high core-forming block DPs and is tentatively attributed to chain transfer to polymer, which is well known for polyacrylamide-based polymers. In fact, relatively high dispersities are actually desirable if such copolymers are to be used as viscosity modifiers because solution viscosity correlates closely with Mw. Static light scattering studies were also conducted, with a Zimm plot indicating an absolute Mw of approximately 2.5 × 106 g mol-1 when targeting a PNAM DP of 6000. Finally, it is emphasized that targeting such high DPs leads to a sulfur content for this latter formulation of just 23 ppm, which minimizes the cost, color, and malodor associated with the organosulfur RAFT agent.

Preparation of a water-soluble polymer having pheophorbide a side chains using glycopolymer assembly

The first trial of incorporation of pheophorbide a (Pba) into a synthetic glycopolymer giving water-soluble ability was carried out, and the polymerization reaction of each monomer proceeded in DMSO to afford the desired glycopolymer having Pba side chains. Characterization of the polymer was performed by means of spectroscopic analyses and thermal studies, and the results supported the desired macromolecular architecture.

Ultrasonic Velocity and Related Parameters Study of PCE Water-Soluble Polymer

Density, viscosity and ultrasonic velocity of aqueous solutions of polycarboxylate ether [PCE] superplastiziser polymer at one of a thoughtful concentrations and temperatures (298.15, 303.13, 308.15 and 313.15)K. different interplay parameters were calculated by the investigational values of density, viscosity and ultrasonic velocity of polycarboxylate ether Water-Soluble Polymer. The viscosity of superplastiziser polymer solution will increase with growing awareness of aqueous answers of polycarboxylate ether. The ultrasonic speed increases from 298.15 K to 308.15K, at that time yet again decreases for 313.15K because the temperature will increase, density, adiabatic compressibility and intermolecular free length duration lower and ultrasonic velocities, acoustic impedance, molar volumes and molar sound velocities turned into discovered to will increase. The ultrasonic velocities to start with boom then decreases with growing consciousness of polycarboxylate ether. For 0.05 polycarboxylate ether it indicates most ultrasonic velocities

Water soluble polymer binder with good mechanical property and ionic conductivity for high performance lithium sulfur battery

Binder as one of the important components in lithium sulfur (Li–S) battery determinates the stability of the active electrode. However, the volume expansion, poor ionic conductivity and the dissolution of polysulfides in sulfur cathode with traditional binders still restrict the application of Li–S battery. Herein, a water-soluble functional binder (HMM/PAA) is elaborately designed to realize the strong interaction with polysulfide and the good mechanical property via a condensation reaction between polyacrylic acid (PAA) and hexamethylolmelamine (HMM). The abundant polar groups in HMM/PAA could anchor polysulfide and impede their migration. The electron-rich oxygen-containing groups would promote the ion transfer for rapid kinetic reaction by coupling with lithium ion. Moreover, the cross-linked network endues the HMM/PAA binder with the good mechanical properties, contributing to the electrode integrity and avoiding the electrode cracks. Therefore, the HMM/PAA-based battery delivers the excellent rate performance and good capacity retention of 838.2 mAh g−1 at 0.2 C even with the sulfur loading of 5.7 mg cm−2. This work provides an economical and effective strategy for water-soluble binder in high-performance Li–S battery.

Antioxidant Polymers with Phenolic Pendants for the Mitigation of Cellular Oxidative Stress.

Overproduction of reactive oxygen species (ROS) in cells is a major health concern as it may lead to various diseases through oxidative damage of biomolecules. Commonly used traditional small molecular antioxidants (polyphenols, carotenoids, vitamins, etc.) have inadequate efficacy in lowering excessive levels of ROS due to their poor aqueous solubility and bioavailability. In response to the widespread occurrence of antioxidant polyphenols in various biorenewable resources, we aimed to develop water-soluble antioxidant polymers with side chain phenolic pendants. Four different types of copolymers (P1-P4) containing phenyl rings with different numbers of hydroxy (-OH) substituents (0: phenylalanine, 1: tyrosyl, 2: catechol, or 3: gallol) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization with a desired molar mass (8500-10000 g/mol) and a narrow dispersity (Đ ≤ 1.3). After successful characterizations of P1-P4, their in vitro antioxidant properties were analyzed by different methods, including 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+), 4,4'-diamino-3,3',5,5'-tetramethylbiphenyl (TMB), and β-carotene (βC) assays. Our results revealed that the gallol pendant polymers can effectively scavenge ROS. Furthermore, electron paramagnetic resonance (EPR) spectroscopy with DPPH• also confirmed the radical quenching ability of the synthesized polymers. The gallol pendant polymers, at a well-tolerated concentration, could effectively penetrate the macrophage cells and restore the H2O2-induced ROS to the basal level. Overall, the present approach demonstrates the efficacy of water-soluble antioxidant polymers with gallol pendants toward the mitigation of cellular oxidative stress.

Amplification-Free Digital Immunoassay down to the Attomolar Level by Synergistic Sedimentation of Brownian Motion Suppression and Dehydration Transfer.

Amplification-free digital immunoassays (DIAs) typically utilize optical nanoparticles to enhance single immunocomplex molecule detection. The efficiency and uniformity of transferring the nanoparticles from a bulk solution to a solid surface determine the limit of detection (LOD) and the accuracy of DIAs. Previous methods suffer from issues like low efficiency, nonuniform distribution, and particle aggregation. Here, we present a novel technique named synergistic sedimentation of Brownian motion suppression and dehydration transfer (SynSed) for nanoparticles using water-soluble polymers. The efficiency of transferring quantum dots (QDs) was increased from 10.7 to 91.4%, and the variation in QD distribution was restricted to 8.8%. By incorporating SynSed into DIAs, we achieved a remarkable reduction in the LOD (down to 3.9 aM) for carcinoembryonic antigen and expanded the dynamic range to cover 3 orders of magnitude in concentration, ranging from 0.01 to 10 fM. DIAs enhanced with SynSed possess ultrahigh sensitivity, advanced accuracy, and specificity, offering a great premise in early disease diagnostics, risk stratification, and treatment response monitoring.

Engineered Nanocomposite Coatings: From Water-Soluble Polymer to Advanced Hydrophobic Performances.

In this work, a water-soluble (hydrophilic) polymer was used to form a hydrophobic coating on silicon substrates (Si) in a two-step process comprising (i) the transformation of the polymer into an insoluble material and (ii) the structuring of this coating at nanometric and micrometric scales to achieve the desired hydrophobic behavior. Polyvinylpyrrolidone (PVP), a water-soluble commodity polymer, was crosslinked using benzophenone and UV irradiation to produce a water-insoluble PVP coating. The nanometric scale roughness of the coating was achieved by the addition of silica nanoparticles (NPs) in the coating. The micrometric scale roughness was achieved by forming vertical pillars of PVP/NP coating. To prepare these pillars, a perforated polystyrene (PS) template was filled with a PVP/NP suspension. Micrometer scale vertical pillars of PVP/silica NPs were produced by this method, which allowed us to tune the wettability of the surface, by combining the micrometric scale roughness of the pillars to the nanometric scale roughness provided by the nanoparticles at the surface. By adjusting the various experimental parameters, a hydrophobic PVP coating was prepared with a water contact angle of 110°, resulting in an improvement of more than 80% compared to the bare flat film with an equal amount of nanoparticles. This study paves the way for the development of a more simplified experimental approach, relying on a blend of polymers containing PVP and NPs, to form the micro/nano-structured PVP pillars directly after the deposition step and the selective etching of the sacrificial major phase.

Molecular Dynamics Study on the Effect of Polyacrylamide on Electric Field Demulsification of Oil-in-Water Emulsion.

The effect of the water-soluble polymer (partially hydrolyzed polyacrylamide, HPAM) in produced water on the demulsification process of the electric field was studied by molecular dynamics simulations. By comparing the coalescence process of oil droplets in the electric field environment with or without HPAM, we find that HPAM in the water phase can promote the coalescence of nearly oil droplets but hinder the deformation and migration of oil droplets. By analyzing the radial distribution function and interaction energy between molecules, we conclude that the existence of HPAM molecules can reduce the hydrophilicity of other molecules through their strong interaction with water, and sodium ions (Na+) have strong interaction with bound water in the process of breaking away from HPAM, thus leading the movement of water molecules. At the same time, the influence of HPAM molecules located between the two oil droplets on the demulsification process was also studied. The HPAM molecules and sodium ions located between the two oil droplets also affected the coalescence process of oil droplets under an electric field by interacting with water.