Effect Of Polyacrylic Acid Research Articles

Effect of polyacrylic acid on the corrosion behavior of Alloy 690 in pressurized water reactor secondary water

The effect of polyacrylic acid (PAA) on the corrosion behavior of Alloy 690 in simulated pressurized water reactor secondary water was investigated. The duplex oxide film structure, consisting of a Ni-rich outer layer and a Cr-rich inner layer, was maintained regardless of PAA presence. PAA inhibited the growth of outer Ni-rich particles while promoting Cr enrichment in the inner layer and inducing its amorphization, both enhancing oxidation resistance. However, excess PAA (≥ 500 ppb) suppressed protective oxide formation during initial oxidation, leading to oxygen penetration into the matrix. A PAA concentration of around 250 ppb is considered optimal for steam generators, as it provides the benefits of PAA without adverse effects on the alloy.

Effect of PAA on the structure and transmittance of hollow spherical SiO2 film prepared by sol-gel method

Hollow spherical silica film has been used on glass substrates as an antireflective coating, and PAA is one of the common templates for preparing SiO2 films by sol-gel method. In this paper, the effects of polyacrylic acid (PAA) content on the SiO2 films prepared by the sol-gel method were analyzed using TEM, DLS, XRD, IR, SEM, and the transmission spectrum. The sol containing hollow spherical micelles can be prepared well from tetraethyl orthosilicate (TEOS) as raw material and PAA as water-soluble polymer by improved Stober, and template method. With the increase of PAA content, the particle size of hollow spherical silica colloidal particles increases and the quantity decreases. The sol is attached to the surface of the soda lime glass substrate to form a film by dip-coating method. With the increase of withdrawal speed, the transmittance of the glass increases, and with the increase of PAA content from 0.1g to 0.6g, the sample's transmittance decreases first and then increases.

Inflammogenic effect of polyacrylic acid in rat lung following intratracheal instillation

BackgroundSome organic chemicals are known to cause allergic disorders such as bronchial asthma and hypersensitivity pneumonitis, and it has been considered that they do not cause irreversible pulmonary fibrosis. It has recently been reported, however, that cross-linked acrylic acid-based polymer, an organic chemical, might cause serious interstitial lung diseases, including pulmonary fibrosis. We investigated whether or not intratracheal instillation exposure to cross-linked polyacrylic acid (CL-PAA) can cause lung disorder in rats.MethodsMale F344 rats were intratracheally instilled with dispersed CL-PAA at low (0.2 mg/rat) and high (1.0 mg/rat) doses, and were sacrificed at 3 days, 1 week, 1 month, 3 months and 6 months after exposure to examine inflammatory and fibrotic responses and related gene expressions in the lungs. Rat lungs exposed to crystalline silica, asbestos (chrysotile), and NiO and CeO2 nanoparticles were used as comparators.ResultsPersistent increases in total cell count, neutrophil count and neutrophil percentage, and in the concentration of the cytokine-induced neutrophil chemoattractant (CINC)-1, CINC-2 and C-X-C motif chemokine 5 (CXCL5), which correlated with lung tissue gene expression, were observed in bronchoalveolar lavage fluid (BALF) from 3 days until at least 1 month following CL-PAA intratracheal instillation. Persistent increases in heme oxygenase-1 (HO-1) in the lung tissue were also observed from 3 days to 6 months after exposure. Histopathological findings of the lungs demonstrated that extensive inflammation at 3 days was greater than that in exposure to silica, NiO nanoparticles and CeO2 nanoparticles, and equal to or greater than that in asbestos (chrysotile) exposure, and the inflammation continued until 1 month. Fibrotic changes also progressed after 1 month postexposure.ConclusionOur results suggested that CL-PAA potentially causes strong neutrophil inflammation in the rat and human lung.

The Effect of Polyacrylic Acid and Sodium Trimetaphosphate on Dentin Hybrid Layer Remineralization: An In Vitro Study.

Adhesive monomers are not able to fully encapsulate collagen fibrils in hybrid layer leaving them vulnerable to time-dependent hydrolytic degradation. The current in vitro study was designed for investigation of the remineralization of the resin-dentin hybrid layer using biomimetic analogs by nanoleakage investigation. Firstly, occlusal enamel of thirty human molars was removed exposing flat surface of dentin, then randomly divided into three main groups according to the different remineralizing protocols (n=10) (R): control group (R0), STMP group (R1), and biomimetic remineralizing group (R2). The dentin surface of the STMP and biomimetic remineralizing groups (R1 and R2) was treated with STMP solution, followed by self-etch adhesive application on dentin surface of all groups, and restored with double 2-mm thick layers of resin composite. Each tooth was sectioned perpendicularly to the resin-dentin interface for producing 1-mm thick slaps. Each group was subdivided into four subgroups according to the incubation time to 24 hours, one month, three months, and 4 months. Retrieved slabs were prepared for nanoleakage for evaluation of metallic silver particles distribution percentage at the resin-dentin interface using digital image analysis software. There was a statistically significant increase in nanoleakage over time in all three groups. However, the third group showed the least increase in metallic silver uptake over time. Hybrid layer could be remineralized by using dual-biomimetic analogs (PAA and STMP). Key words:Hybrid layer, remineralization, nanoleakage, polyacrylic acid, sodium trimetaphosphate.

The role of salt ions and organic molecules in the self-assembled nanolayering

This study investigated effects of polyacrylic acid (PAA) on nanolayering self-assembly, and effects of salt ions on the formation of nanolayering after their chemical interaction with 10-methacryloyloxydecyl dihydrogen phosphate (MDP). ACP–MDP suspension was prepared by dispersing 0.01 g ACP nanoparticles in 4 mL of a 5 wt% MDP solution. Then a PAA solution (100 or 500 μg/mL) was mixed into ACP–MDP suspension. The reaction products were analyzed by transmission electron microscope (TEM). After one of the following metal chlorides (each 0.076 mM of CaCl2, BaCl2, AlCl3, FeCl2, FeCl3, MnCl2, CuCl2, ZnCl2, or MgCl2) was dispersed in a 4 mL MDP solution, they were further analyzed by X-ray diffraction (XRD) and TEM. ACP nanoparticles in the MDP solution could self-assemble into ACP–MDP nanolayering composites. The TEM images show that an amount of ACP nanoparticles were aggregated and fused together after the addition of PAA into ACP–MDP suspensions, while no nanolayering was found. The XRD data and TEM images reveal that nanolayering was self-assembled after the chemical interaction of MDP with some metal chlorides (CaCl2, BaCl2, AlCl3, FeCl2, FeCl3, MnCl2), but not with the others (ZnCl2, CuCl2, MgCl2). PAA could inhibit the self-assembly of nanolayering. Some salt ions play an important role in highly ordered, self-assembled nanostructure after their chemical interaction with MDP. The finding is helpful for functional materials fabrication.

Effect of Polyacrylic Acid on Rheology of Cement Paste Plasticized by Polycarboxylate Superplasticizer.

Viscosity-enhancing agents (VEA) have been widely employed in high flowability cement-based materials, so as to ensure that no bleeding and segregation would occur. However, in most cases, interaction between VEA and superplasticizer would be unavoidable. In this study, the effect of polyacrylic acid (PAA), known as one of the most commonly used VEAs, on rheology performance of cement paste containing polycarboxylate superplasticizer (PCE), was studied. The initial fluidity was assessed with mini slump, and rheological behavior of cement paste was evaluated with rotor rheometer. Adsorption amount was examined with total organic carbon (TOC) analyzer, and the zeta potential was also tested. The interaction between PAA and PCE in the presence of calcium ion (Ca2+) was analyzed with conductivity, X-ray photoelectron spectroscope (XPS), and dynamic light scattering (DLS). The results illustrate that PAA can adsorb onto the surface of cement particles to plasticize cement paste, being similar to PCE. In the presence of Ca2+, PAA can be curled and crosslinked, as a result of the combination between carboxyl groups (COO−) and Ca2+, thereby affecting the adsorption performance and conformation behavior. It is interesting that negative impact of PAA on dispersion efficiency of PCE can be demonstrated; one reason is the reduced adsorption amount of PCE by PAA competitively adsorbing onto the cement surface, and another possible reason is the invalided PCE by adsorption of PAA. Additionally, molecular weight of PAA should be considered if being used as VEA in PCE system.

The effect of polyacrylic acid on the surface properties of calcite and fluorite aiming at their selective flotation

The effect of polyacrylic acid on the surface properties of calcite and fluorite aiming at their selective flotation

The effect of polyacrylic acid and reaction conditions on nanocluster formation of precipitated calcium carbonate on microcellulose

The precipitation of micro- and nanoparticles of calcium carbonate onto lignocellulosic microfibers was investigated at different microfiber concentrations with and without polyacrylic acid (PAA), i.e. a polymer commonly used to form polymer-induced liquid precursors of CaCO3. Concentrations of PAA, Ca(OH)2, CO2 and microfiber were varied in order to study the impact of reaction conditions on PCC formation in a batch reactor operated at ambient temperature. High resolution scanning electron micrographs of the samples show that both microfiber concentration and PAA dosage affected the nucleation and crystal growth of PCC filler on cellulosic fiber. Interestingly, at higher microfiber concentrations, larger amount of nano-sized spherical crystals were formed on the microfibers. A higher dosage of PAA, on the other hand, resulted in less nucleation on the microfiber, suggesting a preferential bulk nucleation mechanism. A higher concentration of PAA during the precipitation also led to the formation and stabilization of amorphous CaCO3, which was supported by SEM images and XRD analysis (lack of characteristic crystal structure).

Effect of polyacrylic acid on polymerization and deposition of silicic acid in geothermal water: A case study at Takigami geothermal power plant, Oita Prefecture

Effect of polyacrylic acid on polymerization and deposition of silicic acid in geothermal water: A case study at Takigami geothermal power plant, Oita Prefecture

Effect of polyacrylic acid on the corrosion behavior of carbon steel and magnetite in alkaline aqueous solutions

The effect of polyacrylic acid on the corrosion behavior of carbon steel and magnetite was investigated in alkaline aqueous solutions at 25°C using potentiodynamic polarization and zero resistance ammetry. The corrosion current density of carbon steel was increased by the addition of 100 ppm polyacrylic acid, whereas that of magnetite was decreased. Carbon steel acted as the anode of the galvanic couple between carbon steel and magnetite, regardless of the presence of polyacrylic acid. In this couple, the galvanic corrosion current density of carbon steel decreased by the addition of 100 ppm polyacrylic acid.

Polymer-Coated Metal-Oxide Nanoparticles Inhibit IgE Receptor Binding, Cellular Signaling, and Degranulation in a Mast Cell-like Cell Line.

Previous reports have shown that nanoparticles (NPs) can both enhance and suppress immune effector functions; however the mechanisms that dictate these responses are still unclear. Here, the effects of polyacrylic acid (PAA) functionalized metal‐oxide NP are investigated on RBL‐2H3 (representative mammalian granulocyte‐like cell line) cell viability, cellular degranulation, immunoglobulin E (IgE) receptor binding, and cell signaling pathways related to immune function. The increasing development of PAA‐NPs as pesticide dispersants and as drug carriers in therapeutics necessitates their investigation for safe production. Using two in vitro experimental approaches, this study demonstrates that pre‐exposing RBL‐2H3 cells, or IgE antibodies, to PAA‐NPs (TiO2, CeO2, ZnO, Fe2O3, and PAA‐Capsules (NP coating control) over 24 h, significantly decrease the binding capacity of IgE for Fcε receptors, inhibit the phosphorylation of intracellular signaling proteins (e.g., MAPK ERK) that mediate degranulation, and inhibited RBL‐2H3 cell degranulation. In addition, and unlike the other NPs tested, PAA‐TiO2 significantly reduced RBL‐2H3 viability, in a time (4–24 h) and dose‐dependent manner (>50 μg mL−1). Together, these data demonstrate that PAA‐NPs at sub‐lethal doses can interact with cell surface structures, such as receptors, to suppress various stages of the RBL‐2H3 degranulatory response to external stimuli, and modify immune cell functions that can impact host‐immunity.

Effect of polyacrylic acid on dentin protease activities

ObjectiveThis study tested whether treatment of demineralized dentin with polyacrylic acid (PAA) has any activatory or inhibitory activity on dentin matrix metalloproteinases (MMP)s or cathepsin K (CAT-K). MethodsDentin beams (1mm×2mm×6mm; n=10) were completely demineralized with EDTA. After initial dry mass assessment, the beams were dipped into 37% phosphoric acid (PA), PA+2% benzalkonium chloride (BAC), PA+2% chlorhexidine digluconate (CHX), 10% PAA, PAA+BAC or PAA+CHX for 20s. Demineralized beams without treatment served as control. All beams were incubated in simulated body fluid (SBF) for 1 week and the dry mass loss was evaluated. Aliquots of SBF were used to analyze solubilized telopeptide fragments using ICTP as indicator of MMP-mediated collagen degradation and CTX for CAT-K-mediated degradation. Additional demineralized beams (n=10) were used to measure the influence of different chemical treatments on total MMP activity of EDTA-demineralized dentin using generic MMP assay. Data were analyzed by ANOVA (α=0.05). ResultsDry mass loss ranged from 6% (PA) to 2% for (PA-BAC) or (PAA-BAC) (p<0.05). ICTP release of PAA-treated group was significantly higher (p<0.05) than the control, and not significantly different from the PA group (p>0.05). PA+CHX or PAA+CHX and PAA+BAC showed significantly lower ICTP than PA or PAA groups (p<0.05). CAT-K activity increased significantly after 10% PAA treatment compared to control (p<0.05) or to PA postreatment. SignificanceDemineralized dentin treated with 10% polyacrylic acid activated CAT-K more than 37% phosphoric acid; 2% chlorhexidine digluconate seems to be a better inhibitor of MMPs and CAT-K than 2% benzalkonium chloride.

Effect of Polyacrylic Acid and Polyacrylamide on Clouding Behavior of Triton-X-100 in Aqueous Medium

Abstract The cloud point (CP) of Triton-X-100 have been studied at various concentration of surfactant in pure and mixed system with water soluble polymers polyacrylic acid (PAA) and polyacrylamide (PAM). The CP of Triton-X-100 was found to be increases with increasing surfactant concentration. The CP of Triton-X-100 has found to decrease with increase of mass of the additives PAA and PAM. The same trend was observed for all surfactant concentrations in presence of PAA and PAM. Considering CP as a threshold temperature of the solubility, the thermodynamic parameters of the clouding process (ΔG0 cl, ΔH0 cl and ΔS0 cl) have been evaluated using “Phase Separation Model”. The results indicate that the clouding phenomenon of Triton-X-100 is exothermic and in presence of polymer additives the process is endothermic and non-spontaneous.

Effect of Polyacrylic Acid on Retarding Action and Property of Gypsum Plasters

Polyacrylic acid was synthesized and used as a retarder additive to prolong the setting time of gypsum plasters. The gypsum paste with the polyacrylic acid at the concentration of 0, 0.1%, 0.2%, 0.3%, 0.4% and 0.5% was studied. The water/gypsum mass ratio was 0.56. The influence of polyacrylic acid concentration on the initial and finial setting time, hydration temperature, morphology of hardened gypsum and mechanical property were extensively investigated. The results show that polyacrylic acid is favorable to increase the setting time which was associated with the reaction of carboxylic group and calcium from the hemihydrate dissolution. The morphology of hardened gysum varied when polyacrylic acid is used. The increase concentration of polyacrylic acid results in a decrease in hydration heat release, flexural and compressive strength.

Polyacrylic Acid‐Assisted Crystallization Phenomena of Carbonate Crystals

AbstractThe effects of polyacrylic acid (PAA) on the crystallization of carbonates were investigated, revealing a great influence of PAA on the shape, size and polymorph type of the carbonate crystals. Carbonate crystallization was performed through reaction crystallization in a single‐jet system. The obtained crystals were measured and characterized by scanning electron microscopy and X‐ray diffraction. In lithium carbonate, PAA especially influenced the growth phase, inhibited agglomeration and changed the crystal shape into high‐aspect rods. In addition, the degree of the growth inhibition effect was molecular weight dependent and the inhibition effect was also different on each face. In calcium carbonate, an improvement of the monodispersity was observed with miniaturization, under particular conditions. Elongated calcite was found under a slow supersaturation rate. In addition, the molecular weight of PAA affected the polymorph selectivity. Therefore, PAA affected the crystallization phenomena of carbonates, and prospected crystals were obtained by changing the operation conditions.

Influence of Polymer Additive on Synthesis of ZnO Nanoparticle by Precipitation Method

The effects of polyacrylic acid (PAA) as an additive on ZnO nanoparticles synthesized by precipitation method is investigated. It is found that ZnO synthesized exhibits a crystalline structure with hexagonal structure of the wurtzite. Primary size of ZnO nanoparticles synthesized can be controlled by PAA concentrations. Increasing of PAA concentration provide small particle size. Addition of 1 wt% PAA can be obtained the average primary size around 20 nm. Additionally, ZnO synthesized using PAA exhibits zeta potential value higher than ZnO synthesized without PAA. With the increasing PAA concentration, Zeta potential value increase. It indicates that ZnO synthesized using 0.5-1 wt% PAA can be well-dispersed in aqueous system and promote highly stable suspension.

Interaction of polyacrylic acid coated and non-coated iron oxide nanoparticles with human neutrophils

Iron oxide nanoparticles (ION), with different coatings and sizes, have attracted extensive interest in the last years to be applied in drug delivery, cancer therapy and as contrast agents in imagiologic techniques such as magnetic resonance imaging. However, the safety of these nanoparticles is still not completely established, particularly to host defense systems that are usually recruited for their clearance from the body. In this paper, given the importance of neutrophils in the immune response of the organism to nanoparticles, the effect of polyacrylic acid (PAA)-coated and non-coated ION on human neutrophils was evaluated in vitro, namely their capacity to activate the oxidative burst and to modify their lifespan. The obtained results showed that the studied PAA-coated and non-coated ION triggered neutrophils’ oxidative burst in a NADPH oxidase dependent manner, and that PAA-coated ION increased — while non-coated ION prevented — apoptotic signaling and apoptosis. These effects may have important clinical implications in biomedical applications of ION.

Transformation of the structural organization of clay sediments and soils under the impact of polyelectrolytes

The effects of polyacrylic acid (PAAc) and polyacrylamide (PAA) adsorption by quartz sand, montmorillonite, kaolinite, gray forest soil, and chernozem on the texture of the sorbents were studied. It was shown that the polymolecular adsorption was typical of the applied polyelectrolytes. The addition of PAA in a concentration of 0.05% to the solution resulted in consolidation of the sediments with a decrease in their volume. In the case of montmorillonite, a loose gel precipitate formed; its volume decreased by about 6% during the experiment. The adsorption of polyelectrolytes slightly affected the average radii, total surface area, and volume of the pore space (within 4–20%). The transformation of the surface of minerals and soils under the action of polyelectrolytes resulted in a significant change in the differential pore volume. The number of pores of about 0.0014 μm in size hardly changed at all. However, wider pores (0.011–0.45 μm) appeared. The adsorption of PAAc resulted in the appearance of wide pores (1.6–22.0 μm), and the adsorption of PAA resulted in the appearance of two narrow classes of micropores. A much more even distribution of differential porosity in the range of 3.6–4.5 μm was revealed. Thus, the transformation of the surface of adsorbents by polyelectrolytes led to changes in the pore-size distribution.

Effect of polyacrylic acid on the interface and bond strength of self-adhesive resin cements to dentin.

To examine the influence of 11.5% polyacrylic acid pretreatment on the interface and bond strength of self-adhesive resin cements (Maxcem Elite, RelyX Unicem, SeT) to dentin. Fifty-six third molars were randomly divided into seven groups: RelyX ARC as control (ARC), RelyX Unicem (RLXU), Maxcem Elite (MCE), SeT (ST), polyacrylic acid+RelyX Unicem (RLXU-P), polyacrylic acid+Maxcem Elite (MCE-P), and polyacrylic acid+SeT (ST-P). Resin composite blocks were luted to flat dentin. After storage in distilled water for 24 h, sticks with a cross-sectional area of ca 0.80 mm2 were obtained (n = 24 per group) and submitted to a microtensile bond strength (µTBS) test in a universal testing machine at a crosshead speed of 0.5 mm/min. Two sets from each group were sectioned mesiodistally in the center of the crown and observed with a scanning electron microscope at 4000X magnification. The mean results of the µTBS test (MPa) followed by the same letter do not differ statistically significantly according to ANOVA and Tukey's post-hoc test (p < 0.05): ARC = 24.19 (± 6.90)a, RLXU-P = 23.12 (± 6.18)a, MCE-P = 13.09 (± 5.87)b, RLXU = 10.23 (± 2.88)b,c, and MCE = 8.14 (± 4.63)c. All SeT specimens failed during the cutting procedure. The hybrid layer was not observed for the self-adhesive resin cements, and resin tags were observed for RelyX Unicem and Maxem Elite when dentin was pretreated with polyacrylic acid. Pretreatment with 11.5% polyacrylic acid was effective for bonding RelyX Unicem and Maxcem Elite to dentin.

Effects of Polyacrylic Acid on the Suppression of Fe Deposition on Graphite for Lithium-Ion Batteries

In order to suppress the capacity fading of graphite negative-electrodes that is caused by the dissolution of LiFePO4 positive-electrode materials, the effects of the glue-like binder (polyacrylic acid) on the suppression of Fe deposition on the graphite electrodes were examined. The electrochemical properties of graphite electrodes using PAA as the binder were investigated by cycling test, cyclic voltammetry and electrochemical impedance spectroscopy in three kinds of different Fe content electrolyte solution. The graphite electrodes using PAA as the binder exhibit better cycle performance than those using PVDF as the binder in all electrolyte solution, and the reduction peaks occur at 1.8 V, which is corresponding to the Fe deposition process on the graphite electrodes, are remarkably weakened by using PAA as the binder. The growth rate of Rcell and Rct for graphite electrode after cycled in Fe-containing electrolyte are also significantly reduced. The SEM and XPS analysis show that the PAA binder can modify the surface film and block the electroreduction of iron ions on the graphite electrode.