1,638 research outputs found

    Epoxy Phosphonate Ester as a Coupling Agent for Transition Metal and Metal Oxide Surfaces

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    A method for surface modification of a substrate comprising surface oxide and/or hydroxy groups, with a compound comprising an ester group and an epoxy ring, wherein the epoxy group remains intact after the reacting. A method for surface modification of a substrate comprising surface oxide and/or hydroxy groups, with a compound comprising an ester group and a functionalized epoxy ring, wherein the functionalized epoxy group remains intact after the reacting. A composite material comprising surface-modified metal oxide nanoparticles dispersed within a polymeric material, wherein the surface modification comprises a compound comprising an ester group and an epoxy ring is also described

    Development of Vulcanizable Elastomers Suitable for Use in Contact with Liquid Oxygen Second Annual Summary Report, 9 May 1964 - 8 May 1965

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    Thermal properties of fluorine containing polymers for development of vulcanizable elastomers suitable for use in contact with liquid oxyge

    Re-Crosslinking Particle Gel for Co₂ Conformance Control and CO₂ Leakage Blocking

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    The present invention generally relates to the composition of particle gels for CO2-EOR and CO2 storage. More particularly, CO2 resistant particle gels are provided that can re-crosslink at subterranean conditions. These particle gels can be deployed to improve the conformance of CO2 flooding, CO2 huff-puff, or Water-Alternative-Gas (WAG). The applications may also involve CO2 storage, such as the blocking of CO2 leakage and similar CO2 processing

    Comprehensive Review of Polymer and Polymer Gel Treatments for Natural Gas-Related Conformance Control

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    Conformance problems often exist in natural gas-related activities, resulting in excessive water production from natural gas production wells and/or excessive natural gas production from oil production wells. Several mechanical and chemical solutions were reported in the literature to mitigate the conformance problems. Among the chemical solutions, two classes of materials, namely polymer gels and water-soluble polymers, have been mostly reported. These systems have been mainly reviewed in several studies for their applications as water shutoff treatments for oil production wells. Natural gas production wells exhibit different characteristics and have different properties which could impact the performance of the chemical solutions. However, there has not been any work done on reviewing the applications of these systems for the challenging natural gas-related shutoff treatments. This study provides a comprehensive review of the laboratory evaluation and field applications of these systems used for water control in natural gas production wells and gas shutoff in oil production wells, respectively. The first part of the paper reviews the in-situ polymer gel systems, where both organically and inorganically crosslinked systems are discussed. The second part presents the water-soluble polymers with a focus on their disproportionate permeability reduction feature for controlling water in gas production wells. The review paper provides insights into the reservoir conditions, treatment design and intervention, and the success rate of the systems applied. Furthermore, the outcomes of the paper will provide knowledge regarding the limitations of the existing technologies, current challenges, and potential paths forwards

    Effect of Phosphoric Acid Anion Structure on the Corrosion Inhibition of Steel by Polyaniline

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    Conductive polymers such as polyaniline (PAni) have been examined as candidates for replacing the existing chromate systems. Protonation of emeraldine base creates polarons and bipolarons, single and paired radical cations, respectively, of higher bond energy levels within the molecular orbital band gap.\u27 For a conductive coating, considerable delocalization of corrosion charge and potential may be obtained along or between the polymer chains, because of high electron mobility. Current corrosion systems based on polyaniline typically rely on sulfuric or sulfonic acids as a dopant material, since synthetic techniques utilize persulfates as the oxidant of choice. In our experience, sulfonic/sulfuric acid systems do not produce adequate corrosion protection. However, few studies have been made of alternative dopant anions. Presumably additional studies are deemed of limited benefit because the persulfate synthesis is prevalent and time intensive purifications are required for replacing an existing sulfonic/sulfuric dopant anion. A. dopant study could yet be important to achieving a more effiCient inhibition system. Phosphonates are derivatives of phosphonic acids that contain direct phosphorous-to-carbon bonds (P-C). The P-C bonds are more resistant to hydrolysis than the P-O-C bonds of orgamc phosphates.3 Phosphonic acids are used as scale inhibitors in. Aqueous systems, the use of these acids as dopants in polyamhne could improve corrosion protection exhibited by polyaniline. Kinle.n el aL4 have reported that phosphonic acid doped polyamhne in polyvinylbutyrallatex coatings showed decreasing galvanic activity with time, providing pinhole passivation. We report testing of an Identical series of doped polyanilines as that of Kinlen, et aL applied in an epoxy polyamide coating system

    Effects of N-Cadherin Disruption on Spine Morphological Dynamics

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    Structural changes at synapses are thought to be a key mechanism for the encoding of memories in the brain. Recent studies have shown that changes in the dynamic behavior of dendritic spines accompany bidirectional changes in synaptic plasticity, and that the disruption of structural constraints at synapses may play a mechanistic role in spine plasticity. While the prolonged disruption of N-cadherin, a key synaptic adhesion molecule, has been shown to alter spine morphology, little is known about the short-term regulation of spine morphological dynamics by N-cadherin. With time-lapse, confocal imaging in cultured hippocampal neurons, we examined the progression of structural changes in spines following an acute treatment with AHAVD, a peptide known to interfere with the function of N-cadherin. We characterized fast and slow timescale spine dynamics (minutes and hours, respectively) in the same population of spines. We show that N-cadherin disruption leads to enhanced spine motility and reduced length, followed by spine loss. The structural effects are accompanied by a loss of functional connectivity. Further, we demonstrate that early structural changes induced by AHAVD treatment, namely enhanced motility and reduced length, are indicators for later spine fate, i.e., spines with the former changes are more likely to be subsequently lost. Our results thus reveal the short-term regulation of synaptic structure by N-cadherin and suggest that some forms of morphological dynamics may be potential readouts for subsequent, stimulus-induced rewiring in neuronal networks

    Transport And Plugging Performance Evaluation Of A Novel Re-Crosslinkable Microgel Used For Conformance Control In Mature Oilfields With Super-Permeable Channels

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    Preformed particle gels (PPG) have been widely applied in oilfields to control excessive water production. However, PPG has limited success in treating opening features because the particles can be flushed readily during post-water flooding. We have developed a novel micro-sized Re-crosslinkable PPG (micro-RPPG) to solve the problem. The microgel can re-crosslink to form a bulk gel, avoiding being washed out easily. This paper evaluates the novel microgels\u27 transport and plugging performance through super-permeable channels. Micro-RPPG was synthesized and evaluated for this study. Its storage moduli after fully swelling are approximately 82 Pa. The microgel characterization, self-healing process, transportation behavior, and plugging performance were investigated. A sandpack model with multi-pressure taps was utilized to assess the microgel dispersions\u27 transport behavior and plugging efficiency. In addition, micro-optical visualization of the gel particles was deployed to study the particle size changes before and after the swelling process. Tube tests showed that micro-RPPG could be dispersed and remain as separate particles in water with a concentration below 8,000 ppm, which is a favorable concentration for gel treatment. However, during the flooding test, the amount of microgel can be entrapped in the sandpack, resulting in a higher microgel concentration (higher than 8,000 ppm), endowing the gel particles with re-crosslinking ability even with excessive water. The microgel could propagate through the sandpack model, and the required pressure gradient mainly depends on the average particle/pore ratio and gel concentration. The gel dispersion significantly reduced channel permeability, providing sufficient resistance to post-water flooding (more than 99.97 % permeability reduction). In addition, the evaluation of micro-RPPG retention revealed that it is primarily affected by both gel concentration particle/pore ratios. We have demonstrated that the novel recrosslinkable microgel can transport through large channels, but it can provide effective plugging due to its unique re-crosslinking property. However, by this property, the new microgel exhibits enhanced stability and demonstrates resistance to being flushed out in such high-permeability environments. Furthermore, with the help of novel technology, it is possible to overcome the inherited problems commonly associated with in-situ gel treatments, including chromatographic issues, low-quality control, and shearing degradation

    Biomaterial Compositions

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    Biomaterial compositions comprising organosilicon monomers (such as silorane monomers) and chemical curing systems or dual chemical/light curing systems, in conjunction with optional tetraoxaspiro[5.5]undecanes (“TOSUs”) and/or fillers. The present invention is directed to biomaterial compositions, as well as methods for manufacturing the same, and methods of using the compositions. The biomaterial composition comprises one or more organosilicon monomers (such as a silorane) and a chemical curing system or dual chemicaVlight curing system for polymerizing the 10 monomer(s). The compositions may include one or more tetraoxaspiro[5.5]undecanes “TOSUs”) and/or fillers. Accelerators (such as photoacids), photosensitizers, and/or electron donors may also be included in the composition as appropriate
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