Exfoliated layers of two-dimensional materials with high surface activity can adsorb polymer chains to induce nucleation effects and enhance the high-temperature resistance of polymer nanocomposites. Herein, a novel polymer nanocomposite (AAS/I-Mt), comprising acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), sodium p-styrenesulfonate (SSS), and sodium 1-dodecanesulfonate-intercalated montmorillonite (I-Mt), was prepared via in situ polymerization. The composition, structure, and morphology of AAS/I-Mt were confirmed using various characterization methods. Thermogravimetric analysis and high-temperature apparent viscosity measurements demonstrated the excellent thermal stability of AAS/1.0 wt% I-Mt. After aging at 200 °C for 16 h, the apparent viscosity of a 10 g L−1 AAS/1.0 wt% I-Mt aqueous solution was 251.7 mPa s. Moreover, after aging at 180 °C for 16 h, the fluid loss under the American Petroleum Institute standard conditions (FLAPI) was 8.0 mL in a fresh-water-based drilling fluid system with 1.0 wt% AAS/1.0 wt% I-Mt, compared to 39.1 mL in the similar system without AAS/1.0 wt% I-Mt. Furthermore, the FLAPI of a saturated brine-based drilling fluid system with 1.0 wt% AAS/1.0 wt% I-Mt was 8.6 mL. Additionally, scanning electron microscopy, transmission electron microscopy, and zeta potential analyses suggested the strong adsorption between the exfoliated I-Mt nanosheets and polymer chains. The uniformly dispersed nanosheets in AAS/I-Mt thickened and toughened the polymer chains and decreased the porosity of the nanocomposite, reducing the fluid loss in water-based drilling fluids at high temperatures. The multifunctional AAS/I-Mt polymer nanocomposite shows potential as an effective additive in high-temperature oil and gas water-based drilling fluids.
19 August 2011 in Journal of Applied Polymer Science
In this article, polystyrene/organic montmorillonite (PS/OMMT) nanocomposite was prepared via in-situ emulsion polymerization of styrene in the presence of organic montmorillonite. The certain amount of PS/OMMT nanocomposite and silicone oil mixtures provided novel nanocomposite lubricant additives of drilling fluid. Their experiment evaluations showed that the nanocomposite lubricant drilling fluid had the temperature resistance to increase up to 200°C, high lubricant with base drilling fluid compatibility, and stable rheological property. At 1.0 wt.% nanocomposite lubricant load in the base drilling fluid, the lubrication coefficient reduction rate reached 85.0%, the foaming rate was so low to 0.53%∼1.56%, and the filtration loss was decreased. This provided multifunctional practical nanocomposite lubricants and working fluids.
Novel polymer nanocomposites of methacryloyloxy ethyl dimethyl hexadecyl ammonium bromide-modified montmorillonite (O-MMt) with acrylamide/sodium p-styrene sulfonate/methacryloyloxy ethyl dimethyl hexadecyl ammonium bromide (ASD/O-MMt) were synthesized via in situ polymerization. The molecular structures of the synthesized materials were confirmed using Fourier-transform infrared and 1H-nuclear magnetic resonance spectroscopy. X-ray diffractometry and transmission electron microscopy revealed well-exfoliated and dispersed nanolayers in the polymer matrix, and scanning electron microscopy images revealed that the well-exfoliated nanolayers were strongly adsorbed on the polymer chains. The O-MMt intermediate load was optimized to 1.0%, and the exfoliated nanolayers with strongly adsorbed chains were controlled. The properties of the ASD/O-MMt copolymer nanocomposite, such as its resistance to high temperature, salt, and shear, were significantly enhanced compared with those obtained under other silicate loads. ASD/1.0 wt% O-MMt enhanced oil recovery by 10.5% because the presence of well-exfoliated and dispersed nanolayers improved the comprehensive properties of the nanocomposite. The large surface area, high aspect ratio, abundant active hydroxyl groups, and charge of the exfoliated O-MMt nanolayer also provided high reactivity and facilitated strong adsorption onto the polymer chains, thereby endowing the resulting nanocomposites with outstanding properties. Thus, the as-prepared polymer nanocomposites demonstrate significant potential for oil-recovery applications.
27 September 2023 in Advances in Engineering Technology Research
In oil and gas exploration and development, the complex working conditions of high temperature and high pressure are increasing, and the strength decline of silica-cement often occurs under such conditions. In this work, the metakaolin influence on the mechanical properties and micro-structure of silica-cement at 240 ℃ and 21 MPa condition is comprehensively studied. XRD technique investigated the chemical composition of cement crystal phase, and SEM observed the micro-morphology of high temperature cement. Results showed that the loading metakaolin has reduced porosity by 12.86%, air permeability while greatly increased nanopore (<50nm) by 36.47% and increased nanopore (<10 nm) by 10.34%. Thus, the cement permeability reduced greatly or its anti-channelling enhanced, that is, such results improved the comprehensive performance of cement slurry. These observations, combined with the previously reported the remarkable enhancement of the MK cement compressive strength, represent a major step toward the development of strength retrogression-resistant material at high temperature.
Lithium–sulfur (Li–S) batteries are promising next-generation energy-storage systems but are severely hindered by polysulfide shuttling, sluggish sulfur redox kinetics, and unstable Li2S nucleation/growth behavior. Herein, a multifunctional MXene/carbon nanotube/poly(ethylene oxide) (MX/CNT/PEO)-modified separator is developed to regulate polysulfide behavior and improve interfacial electrochemical stability. In this composite architecture, MXene provides polar sites for lithium polysulfide adsorption, while carbon nanotubes construct interconnected conductive networks and suppress MXene restacking. The incorporation of poly(ethylene oxide) improves interfacial continuity and introduces additional oxygen-containing functionalities within the composite framework. Benefiting from the integrated effects of polar adsorption, conductive pathways, and structural integration, the MX/CNT/PEO-modified separator effectively suppresses polysulfide diffusion, reduces charge-transfer resistance, and promotes more favorable Li2S nucleation/growth behavior. Electrochemical analysis shows that the charge-transfer resistance decreases from 175.9 Ω for pristine PP to 15.7 Ω for the MX/CNT/PEO@PP separator, corresponding to a 91.1% reduction. Potentiostatic Li2S deposition analysis further supports favorable Li2S nucleation/growth behavior on the MX/CNT/PEO-modified interface, after background subtraction. As a result, the Li–S cell with the MX/CNT/PEO@PP separator delivers a high initial discharge capacity of 1613 mAh g−1 at 0.1 C and maintains average capacities of 1331.1 and 803.1 mAh g−1 at 0.1 and 2 C during rate testing, respectively. During long-term cycling at 2 C, the cell retains 319.3 mAh g−1 after 1000 cycles, with an average capacity decay rate of 0.064% per cycle. This work provides a rational composite-interlayer design strategy for multifunctional separator materials in high-performance Li–S batteries.