Instead, they intertwined three individual strands of spun carbon nanotube fibers to make a single yarn, similar to the way conventional yarns used in textiles are constructed - but with a different twist. ![]() In the new study, the research team did not twist the fibers to the point of coiling. Electricity is generated by the coiled yarns by repeatedly stretching and releasing them, or by twisting and untwisting them. Previous versions of twistrons were highly elastic, which the researchers accomplished by introducing so much twist that the yarns coil like an overtwisted rubber band. To make twistrons, the nanotubes are twist-spun into high-strength, lightweight fibers, or yarns, into which electrolytes can also be incorporated. Twistrons sewn into textiles can sense and harvest human motion when deployed in salt water, twistrons can harvest energy from the movement of ocean waves and twistrons can even charge supercapacitors.įirst described by UTD researchers in a study published in 2017 in the journal Science, twistrons are constructed from carbon nanotubes (CNTs), which are hollow cylinders of carbon 10,000 times smaller in diameter than a human hair. Their new version is constructed much like traditional wool or cotton yarns. 26 in Nature Energy, UT Dallas researchers and their collaborators describe improvements to high-tech yarns they invented called "twistrons," which generate electricity when stretched or twisted. We found that an optimum 0.2 vol% concentration of acid‐functionalized GNPs improves the compressive and the shear bond strength of the prepared cement by approximately 42 and 175% as compared to the plain cement, respectively.In a study published Jan. Therefore, eliminating the above‐mentioned water separation can enhance cement sealing properties. On the other hand, the squeeze of water out of the lower parts of the cement slurry and its upward migration can develop preferential paths for oil and gas migration. We measured zero free fluid at room temperature for different concentrations of GNPs, demonstrating uniform dispersion of nanoparticles within the cement matrix. We investigated the effect of modified GNPs on the unconfined compressive strength (UCS), shear bond strength, thickening time, rheological characteristics, and the free fluid content. To examine the role of spatial distribution of GNPs on the hardened cement nanocomposite, samples with different concentrations of GNPs were tested. Also, some experiments were repeated under the pressure and temperature conditions up to 5,160 psi and 126☏, respectively, to examine pumpability and behavior of cement slurry at bottomhole conditions. To mimic downhole conditions, cement slurries are cured at 3,000 psi and 190☏ for 24 hours. The efficiency of proposed methods on the overall properties of the cement is examined before and after its setting. ![]() We present two dispersion methods on the basis of physical and chemical treatments of the surface properties of GNPs. In this study, we focus on the effect of surface‐modified GNPs on the overall mechanical properties of both cement slurry and hardened cement slurry affecting the permeability of cement. GNPs possess high surface area to volume ratios. The purpose of this research is containing or at least minimizing the intrinsic and developed flow paths through the cementitious matrix with the help of surface‐modified GNPs. ![]() On one hand, it is the inherent microstructural defects of cement, including pores and microcracks, that results in the intrinsic permeability of cement, and on the other hand, cracking, micro‐annuli, or other flow paths developed through the disturbed cement by connecting the pre‐existing microstructural defects determine the equivalent permeability of set cement. ![]() The primary role of the cement sheath, which is zonal isolation, can be significantly affected by the permeability of set cement (hardened cement slurry). We propose a novel cement additive made of graphite nanoplatelets (GNPs) for improved hydraulic isolation and durability of oil and gas wells.
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