Water-soluble Organic Polymers Research Articles

Evaporation-induced crystal self-assembly (EICSA) of salt drops regulated by trace of polyacrylamide

The anisotropic growth and the different interface properties of ionic crystal at microscale make it difficult to control and obtain the ordered crystals at macroscale, resulting in rare researches on self-assembly of ionic crystal. The method of evaporation-induced crystal self-assembly (EICSA) has been demonstrated for the construction of highly ordered self-assembly configurations in the sodium chloride (NaCl) drops regulated by trace of water-soluble organic polymer (polyacrylamide, PAM) on the hydrophobic substrate. According to the dynamic behaviors of self-assembly configurations, the concentration phase diagram of configurations is given, showing that EICSA is a process from disorder to order with the increase of the amount of PAM. We interpret this phenomenon as a result of the addition of PAM promotes the nucleation and inhibits the growth, producing a large number of NaCl with small size. Meanwhile, the adhesion of PAM makes NaCl orderly assembled together. Particularly, the mechanisms of the spontaneous lifting of crystals are directly revealed through our experiments. Moreover, we develop the lattice model to explain the physical mechanisms behind the evolution of self-assembly configurations. Furthermore, the dependence of the evaporating rate from regions (III) to (I) on the mixing free energy change is found to be consistent with the Arrhenius behavior. Our results have shown a further understanding of construction and control in self-assembly of ionic crystal, which has great applications in protection of outdoor electronics, conservation of cultural relics and chemical production.

Water-soluble and dispersible porous organic polymers: preparation, functions and applications.

Porous organic polymers (POPs) have attracted increasing attention and emerged as a new research area in polymer chemistry. During the past decade, the intense desirability for application in aqueous scenarios has spawned the development of a specific class of POPs, i.e., water-soluble or dispersible porous organic polymers (WS-POPs) that can allow the implementation of porosity-based functions in aqueous media. In this Tutorial Review, aiming at providing a practical guide to this area, we will discuss recent advances in the preparation of WS-POPs through covalent/dynamic covalent, coordination and supramolecular approaches. As a result of their intrinsic and well-defined porosity, diverse topological architectures as well as unique water-processable features, many water-soluble/dispersible POPs have been demonstrated to exhibit potential for various applications, which include drug, DNA and protein delivery, bioimaging, photocatalysis, explosive detection and membrane separation. We will also highlight the related function of the representative structures. Finally, we provide our perspective for the future research, with a focus on the development of new structures and biofunctions.

Antibacterial effect of Ag-PMANa modified cotton

In this study, the cotton fabric was treated with silver (Ag)-doped sodium polymethacrylate (PMANa) to provide it with antibacterial properties. Ag-doped PMANa, a stable, transparent, and water-soluble organic polymer with antimicrobial activity, was obtained by sequestering Ag+ with the –COO− groups of PMANa polymer via ion exchange method. The antibacterial activity of the Ag-PMANa was evaluated by minimum inhibitory concentration and minimum bactericidal concentration testing using E. coli and S. aureus as representative strains of Gram-negative and Gram-positive bacteria, respectively. Then, the cotton fibers were impregnated with this polymer, and the successful loading was confirmed by characterization of chemical, structural, and morphological properties. The amount of Ag ions released from the antibacterial cotton was determined by Inductive Coupled Plasma Emission Spectrometer. Antimicrobial property against E. coli and S. aureus of the modified cotton was assessed by the oscillation method and compared with that of untreated cotton. The modified cotton fabrics were measured to have an excellent antibacterial effect. Furthermore, the results also showed that the modified cotton is highly stable under washing conditions and under exposure to different light conditions. Intrinsic properties of modified cotton were preserved compared to those of pristine cotton. The morphological characteristics of bacteria were evaluated by SEM and the reducing sugars and proteins that leaked from E. coli and S. aureus were detected to preliminarily explore the antimicrobial mechanism of Ag+. The material prepared herein shows high potential for a broad range of applications in biomedical field.

Ultralong purely organic aqueous phosphorescence supramolecular polymer for targeted tumor cell imaging

Purely organic room-temperature phosphorescence has attracted attention for bioimaging but can be quenched in aqueous systems. Here we report a water-soluble ultralong organic room-temperature phosphorescent supramolecular polymer by combining cucurbit[n]uril (CB[7], CB[8]) and hyaluronic acid (HA) as a tumor-targeting ligand conjugated to a 4-(4-bromophenyl)pyridin-1-ium bromide (BrBP) phosphor. The result shows that CB[7] mediated pseudorotaxane polymer CB[7]/HA–BrBP changes from small spherical aggregates to a linear array, whereas complexation with CB[8] results in biaxial pseudorotaxane polymer CB[8]/HA–BrBP which transforms to relatively large aggregates. Owing to the more stable 1:2 inclusion complex between CB[8] and BrBP and the multiple hydrogen bonds, this supramolecular polymer has ultralong purely organic RTP lifetime in water up to 4.33 ms with a quantum yield of 7.58%. Benefiting from the targeting property of HA, this supramolecular polymer is successfully applied for cancer cell targeted phosphorescence imaging of mitochondria.

Improvement of Water Stability of Sand Admixed with Water-Soluble Organic Polymer

Weak water stability of soil is one of the prime causes of soil erosion and slope damage. To understand the improvement on the water stability of sand by a soluble organic polymer (polyurethane, PU), we have conducted a series of water-stability and turbidity tests to evaluate the effects of different polymer content, densities, and immersion times. The mechanism of the improvements is investigated based on scanning electron and digital microscopes. Our results reveal that the polymer can effectively improve the water stability of sand, where the water-stability coefficient enhanced from zero to 100. The turbidity of the water after oscillation was determined, and its value reduced from 84.5 to 10 and kept stable, which further proved the PU improvement on the water stability of sand. The results can be considered as the reference for construction and management of riverbanks and drainage ditches.

Trace-level and selective detection of uric acid by a luminescent Zn (II) based 1D coordination polymer in aqueous medium

A water soluble luminescent 1D metal organic coordination polymer of Zn(II) [Zn(FDA)(2,2′-bpy)(H2O)]·2H2O (2,2′-bpy = 2,2′-bipyridine and FDA = 2,5-furandicarboxylate), 1 was successfully synthesized by solvothermal method. This crystalline compound 1 showed strong luminescence emission at 325 nm upon excitation at 290 nm in aqueous medium. The luminescence intensity was highly sensitive towards a bio-metabolized purine derivative, uric acid (UA). However, it did not show any considerable response towards structurally similar other purine derivatives like adenine (Adn), guanine (Gua) and theobromine (Tbr). The compound 1 was found to be highly selective and sensitive towards uric acid (UA) with a detection limit of 300 ppb. The sensitivity and selectivity of 1 towards UA was also investigated in the presence of several metal ions, anions and organic bio-molecules which are commonly found in human urine. The results indicated that 1 could be a potential probe for selective detection and estimation of UA in urine. The mechanism of the sensing was explained successfully and it was also supported by DFT calculation.

Polystyrene-block-Poly(ionic liquid) Copolymers as Work Function Modifiers in Inverted Organic Photovoltaic Cells.

Interfacial layers play a critical role in building up the Ohmic contact between electrodes and functional layers in organic photovoltaic (OPV) solar cells. These layers are based on either inorganic oxides (ZnO and TiO2) or water-soluble organic polymers such as poly[(9,9-dioctyl-2,7-fluorene)-alt-(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)] and polyethylenimine ethoxylated (PEIE). In this work, we have developed a series of novel poly(ionic liquid) nonconjugated block copolymers for improving the performance of inverted OPV cells by using them as work function modifiers of the indium tin oxide (ITO) cathode. Four nonconjugated polyelectrolytes (n-CPEs) based on polystyrene and imidazolium poly(ionic liquid) (PSImCl) were synthesized by reversible addition-fragmentation chain transfer polymerization. The ratio of hydrophobic/hydrophilic block copolymers was varied depending on the ratio of polystyrene to the PSImCl block. The ionic density, which controls the work function of the electrode by forming an interfacial dipole between the electrode and the block copolymers, was easily tuned by simply changing the PSImCl molar ratio. The inverted OPV device with the ITO/PS29-b-PSImCl60 cathode achieved the best power conversion efficiency (PCE) of 7.55% among the synthesized block copolymers, exhibiting an even higher PCE than that of the reference OPV device with PEIE (7.30%). Furthermore, the surface properties of theblockcopolymers films were investigated by contact angle measurements to explore the influence of the controlled hydrophobic/hydrophilic characters on the device performances.

Effect of leached cement paste samples with different superplasticiser content on germination and initial root growth of white mustard (Sinapis alba) and cress (Lepidium sativum)

With an annual production of about 10 Gt concrete is by far the most used solid man-made material. In order to adjust the workability of fresh concrete most often so-called superplasticisers, essentially water-soluble organic polymers, are utilised. As concrete is commonly in direct contact with soil or water, the leaching of organic and inorganic compounds and their environmental impact need to be assessed. The present study contributes to this purpose by investigating leachates from hardened cement pastes gained using the horizontal dynamic surface leaching test. Pastes were prepared with and without superplasticiser. The root growths as well as the germination behaviour of cress (Lepidium sativum) and white mustard (Sinapis alba) were examined with respect to phytotoxicity. Different proportions (100, 50, 25 and 12.5%) of the leachates were considered in the test scheme. The results indicate a positive effect of most of the leachates on seed germination and root growth, although statistical significance was only found in some cases. Both test species showed no or only slight harmful effects as relative root growth exceeded always 66% for S. alba and 74% for L. sativum. Seed germination was not negatively influenced by the leachates. Slight beneficial effects on both test species could be observed for leachates containing superplasticiser compared to samples in absence of superplasticiser.

Thermal Resistance and Application of Nanoclay on Polymer Flooding in Heavy Oil Recovery

High molecular weight and water-soluble synthetic organic polymers are currently being used in the field with the hope of enhancing the recovery of oil by water flooding. Nanotechnology has been used in many applications and new possibilities are discovered constantly. Recently, a renewed interest arises in the application of nanotechnology for the upstream petroleum industry. The author focuses on roles of clay nanoparticles on polymer viscosity. Polymer-flooding schemes for recovering residual oil have been in general less than satisfactory due to loss of chemical components by adsorption on reservoir rocks, precipitation, and resultant changes in rheological properties. Rheological properties changes are mainly determined by the chemical structure and mix of the polymers, surface properties of the rock, composition of the oil and reservoir fluids, nature of the added polymers, and solution conditions such as salinity and temperature. On the other hand, the author's focus is on viscosity, temperature, and salinity of solutions polyacrylamide polymer solutions with different nanoparticles. Results show that ultimate oil recovery by nanoclay polymer flooding enhances by a factor of 5.8% in comparison to polymer flooding high salinity and temperature.

Effectiveness of combination lisinopril+hydrochlorothiazide vs. bisoprolol+hydrochlorothiazide in patients with moderate to severe hypertension

Previous work suggests that polycarboxylic acids can be regarded as model compounds for soil fulvic acids and for water-soluble soil organic polymers. Curie-point pyrolysis—gas chromatography—mass spectrometry studies indicate that, on pyrolysis, polycarboxylic acids undergo fragmentation with cyclisation, elimination and decarboxylation reactions and yields two characteristic produces, 2-cyclopenten-1-one and 2,3-dimethylmaleic anhydride. The former is a characteristic pyrolysis product of solids and has been used in the assessment of humus type. Aromatic and phenolic products are also obtained in smaller amounts depending on the polymer molecular weight. Fulvic acids and water-extracted soil organic matter give similar pyrolysis products, together with those derived from polysaccharides and polypeptides. These results support the concept that natural soil organic polymers contain significant amounts of highly carboxylated chains.

Highly Transparent Flexible Clay Film with Organized Polymer

A series of clay-based nanocomposite films were prepared by casting aqueous dispersions of exfoliated montmorillonite clay mixed with various loadings of water-soluble organic polymer. The clay films with a nacre-mimicking structure exhibited excellent flexibility and optical transparency even for high clay content (93 wt%).

Cooling Capacity Optimization: Calculation of Hardening Power of Aqueous Solution Based on Poly(N-Vinyl-2-Pyrrolidone)

Polymer quenchants are becoming increasingly popular as substitutes for traditional quenching media in hardening metallic alloys. Water-soluble organic polymer offers a number of environmental, economic, and technical advantages, as well as eliminating the quench-oil fire hazard. The close control of polymer quenchant solutions is essential for their successful applications, in order to avoid the defects of structure of steels, such as shrinkage cracks and deformations. The aim of the present paper is to evaluate and optimize the experimental parameters of polymer quenching bath which gives the best behavior quenching process and homogeneous microstructure of the final work-piece. This study has been carried out on water-soluble polymer based on poly(N-vinyl-2-pyrrolidone) PVP K30, which does not exhibit inverse solubility phenomena in water. The studied parameters include polymer concentration, bath temperature, and agitation speed. Evaluation of cooling power and hardening performance has been measured with IVF SmartQuench apparatus, using standard ISO Inconel-600 alloy. The original numerical evaluation method has been introduced in the computation software called SQ Integra. The heat transfer coefficients were used as input data for calculation of microstructural constituents and the hardness profile of cylindrical sample.

Synthesis and characterization of hierarchical titania-silica monolith

Titania-silica monoliths with bicontinuous macropores and ordered mesopores were successfully prepared by a double-template technique. The influence of reactants on pore structures and Ti content was studied in detail. The results demonstrated that acid concentration in starting compositions has a great effect on morphologies of the final samples. Besides, it is also found that the changing of water-soluble organic polymers amount and triblock copolymers amount could adjust the pore size of macropores and the order degree of mesopores respectively. Moreover, the addition of fluoride benefits much more titanium atoms incorporate into the framework of silica. Compared with Ti-SBA-15, the hierarchical titania-silica monolith showed better performance on catalytic reaction of large molecules such as epoxidation of cyclohexene to cyclohexene oxide with isopropyl benzene hydroperoxide.

BEHAVIOUR OF UNDERWATER SELF COMPACTING CONCRETE

Antiwashout underwater concrete AWA may be considered for use in a diverse range of work underwater, where its excellent characteristics are of great advantage. Underwater concrete Anti-washout admixture (SIKAMENT 100 SC) is water soluble organic polymers, which increase the cohesion of the concrete in a way, that significantly reduces the washout of the finer particles, i.e. the cementinious material (cement and silica fume) and sand from fresh concrete when it is placed underwater. Researches for underwater concrete are commonly studied but the common mixes of SCC are rarely investigated underwater. In this research, about 50 mixes of normal concrete NC and self compacting concrete SCC were prepared, in order to study the behaviour of under water SCC compared to NC using antiwashout admixtures (SEKAMENT 100 SC) Some parameters were studied such as AWA%, cement content, water cementitious ratio, coarse to fine aggregate ratio, and superplastisizer percent, in order to study the behavior of underwater SCC by measuring washout and out water/underwater minimum relative compressive strength to be added to the guidelines of underwater concrete applications. Optimum values of some AWA components have been clarified; including cement content, water cementitious ratio, sand to aggregate ratio, and superplastisizer percentage.

Effect of molecular mass on boron-doped diamond anodic mineralization of water-soluble organic polymers

Anodic oxidation of a number of water soluble organic compounds with increasing molecular mass from 46 Da to 72,000 Da was systematically investigated in a cell with a boron-doped diamond (BDD) anode under total recycle batch galvanostatic operation conditions. The experiments were designed to start with a similar initial total organic carbon (TOC) level of 200 mg dm −3, thus allowing for elucidating the dependencies of TOC removal kinetics, change in solutions’ pH and mineralization current efficiencies (MCE) on the type and molecular mass of target compound. The TOC removal rates were fitted to pseudo-first order exponential decay expressions, and the apparent kinetic constants for the anodic oxidation of each target compound were estimated. The process performance depended strongly on the compound molecular mass with apparent TOC removal kinetic constants lying in an order-of-magnitude range from 0.17 × 10 −4 s −1 for poly(vinyl alcohol) to 1.67 × 10 −4 s −1 for ethanol. This respectively led to different degrees of TOC removal in the experiments: from high TOC removal (>94%) for the low-molecular mass compounds to much lower one (down to 54%) for poly(vinyl alcohol), which was the compound with the highest molecular mass studied. The changes in the solution pH were well correlated with the respective degrees of TOC removal, thus additionally reflecting the slower kinetics of their oxidation. The results obtained might be useful for process design and optimization, especially when dealing with anodic mineralization of water-soluble polymeric fractions, for which the total organic content is easily assessable.

Synthesis of Baso<sub>4</sub> Nanoparticles by Precipitation Method Using Polycarboxylate as a Modifier

Problem statement: Barium Sulfate (BaSO4) is suitable for many applications because of its whiteness, inertness and high specific gravity. Approach: Nanoparticles of barium sulphate (BaSO4) have been synthesized from barium nitrate by precipitation method in the presence of water soluble organic polycarboxylic polymer as a modifying agent. Transmission electron microscopy, Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray powder diffractometry were used to characterize the products as well as laser grainmeter. Results: The results indicate that spherical BaSO4 nanoparticles are obtained with poor crystalline and diameters ranging from 30-35 nm. Conclusion: The organic polycarboxylate shows as good modifier agent. So, this method can be employed to synthesize higher yield of BaSO4 nanoparticles.

A new empirical test method for the optimisation of viscosity modifying agent dosage in self-compacting concrete

Viscosity modifying admixtures (VMAs) are high molecular weight, water soluble organic polymers that are used to stabilise the rheological properties and consistency of self-compacting concrete (SCC). Most studies on VMA focus on the influence of different types and dosages of VMA on the rheological properties and the compatibility issues between superplasticiser and VMA. To obtain the desired rheological properties and to reduce the cost, optimisation of the VMA dosage is essential. In the present study, a simple method was developed for optimising the VMA dosage for the cementitious pastes of different water to powder ratio. The principle of this method was based on Stokes’ law. Rheological properties of SCC pastes with VMA were studied using a viscometer. The studies were also extended to concrete for validation of the optimised dosage obtained from the cementitious paste tests. The results obtained clearly indicate that the optimised dosage obtained by using the empirical method yields SCC without segregation. The lower dosages are not sufficient enough to control the segregation. On the other hand, dosages higher than optimal resulted in reduced slump flow.

Highly transparent flexible clay films modified with organic polymer: structural characterization and intercalation properties

We are developing transparent flexible clay films with high thermal resistance and gas barrier properties. The clay films were fabricated by casting aqueous dispersions of synthetic Na+-saponite mixed with various loadings of water-soluble organic polymer. In this paper, the structural, optical, and physical properties of the films are reported. The structure of these films has been found to have an alignment of densely packed clay platelets interspersed with polymer chains between clay platelet edges. The parallel stacking of clay platelets is enhanced by adsorption of anionic polymer on the positively charged edges of the clay platelets so that excellent optical transparency is maintained even for high clay loading (up to 90 wt%). Also, polymer chains bounded on particle edges are tightly confined by upper and lower layers of clay platelets, rendering these films more thermally stable. The degradation temperature of the films is more than 350 °C. Differential scanning calorimetry analysis reveals that the melting point of the polymer in the clay layers is shifted towards the higher temperature range, up to 440 °C. However, the segregation of polymers towards the film surface occurs with the polymer loading, which reduces the thermal resistance of the film due to weaker interaction of adsorbed polymer on the film's surface. Consequently, films with higher clay loading (>80 wt%) provide excellent optical and physical properties, these films will be promising for a wide variety of applications such as displays or other electronic devices.

Novel Analysis of Inorganic-Organic Composites using Raman Microscopy

Recently inorganic/organic composites, such as calcium carbonate and water-soluble organic polymer with fine and complex structures have been actively advancing. Therefore, it is necessary to develop a novel analytical method for these materials. In order to solve the problem, a comprehensive non-destructive methodology for the simultaneous quantitative analysis of the calcium carbonate crystal phases in their binary mixtures and organic polymers was developed, based on the use of a Raman microscope. In this method, relative error of aragonite was on a level of X-ray diffraction, while that of organic polymers was 30%.

Novel modification method for inorganic geopolymer by using water soluble organic polymers

The inorganic polymer, geopolymer, has emerged as promising material in various fields for its better properties with respect to ceramics and cement-based materials. This paper focused on examining the effects of five kinds of water-soluble organic polymers on the mechanical and physical properties of uncalcined-kaolinite geopolymer. It was found in the current work that the addition of polyacrylic acid (PAA) and sodium polyacrylate (PAA Na) can obviously improve the compressive strength (maximum: 29.0%), cross-bending strength (maximum: 64.9%) and volume weight of kaolinite Na-PS. In addition, after boiling the samples for 2 h, their weight losses and remnant compressive strength of the composite geopolymers were also improved to 7.5% and 61.2% (maximum values), respectively. On the contrary, polyacrylamide (PAm), polyethylene glycol (PEG) and polyvinyl alcohol (PVA) will greatly decrease the volume weight, weight loss and remnant compressive strength (except for PEG), whereas their contributions to the improvement of mechanical property were not as effective as PAA and PAA Na.