Poly(N-isopropylacrylamide) Hydrogel for Diving/Surfacing Device

Choi, Jung Gi; Gwac, Hocheol; Jang, Yongwoo; Richards, Christopher J.; Spinks, Geoffrey M.; Kim, Seon Jeong

doi:10.3390/mi12020210

Cited by 10 publications

(10 citation statements)

References 19 publications

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“…The interaction between the amide groups becomes more intense and tends to form an eight-membered ring structure . The PNIPAM chain collapses, exposing the hydrophobic isopropyl groups and the hydrophilicity and density of PNIPAM gel decrease, which tends to distribute on the oil–water interface …”

Section: Results and Discussionmentioning

confidence: 99%

“…To visually reflect the process of the co-polymer nano− microspheres moving from the water phase to the water−oil interface during being heated, we place the gel in water at 25 °C and observe the rising process of the gel accompanied by increasing the temperature (Figure 4c). 37 When the temperature exceeds 32 °C, the gel (H3) starts to float up and slowly reaches the water surface as the temperature increases. By contrast, the pure PAM sample (H0) does not move to the oil−water interface.…”

Section: Ift Analysismentioning

confidence: 99%

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Preparation and Properties of Temperature-Sensitive P(NIPAM-AM) Nano–Microspheres in Enhanced Oil Recovery

Zhou

Luo

et al. 2022

Energy Fuels

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As a new kind of water plugging and profile control agents, the polyacrylamide nano−microspheres have been experimentally applied and achieved satisfactory preliminary results in enhanced oil recovery, especially for low-permeability reservoirs. However, the larger swollen particle size and excessive hydrophilicity limit the effect at the oil−water interface. In order to further improve their profile control and flooding effect, the temperature-sensitive poly(N-isopropylacrylamide-acrylamide) nano−microspheres are prepared by inverse microemulsion polymerization. Based on the principle of conformation transition of PNIPAM triggered by simulated high temperature in reservoirs, the particle size and hydrophilicity of the microspheres are reduced, making it easier to reach the oil−water interface, reduce the oil−water interface tension, and enhance the structural disjoining pressure, which improves the spontaneous emulsification effect and removal effect of residual oil on rocks. The swelling properties, hydrophilicity, interfacial activity, and oil displacement properties of the nano−microspheres were also analyzed. The results show that the swelling ratio of the copolymerized nano−microspheres decreases to 1.5. At simulated reservoir temperature (65 °C), the water contact angle of copolymerized gel increases from 43 to 86°, indicating that its hydrophilicity decreases and shows a clear tendency to migrate to the water−oil interface. At 65 °C, 0.1 wt % PNIPAM-based microsphere emulsion (N3) reduces the oil−water interfacial tension from 17.8 to 0.9 mN m −1 . The microscopic oil displacement experiment shows that the recovery efficiency of our designed temperature-sensitive nano−microspheres emulsion is increased by 7%, which is higher than that of the PAM polymer nanosphere. The PNIPAM-based temperature-sensitive nano−microspheres that can function at the oil−water interface have a potential development prospect in low-permeability reservoirs.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Ift Analysismentioning

confidence: 99%

Preparation and Properties of Temperature-Sensitive P(NIPAM-AM) Nano–Microspheres in Enhanced Oil Recovery

Zhou

Luo

et al. 2022

Energy Fuels

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“…This PDF file includes: Supplementary Text Fig. S1 to S15 Table S1 to S4 References (45)(46)(47)(48)(49)(50)(51) Other Supplementary Material for this manuscript includes the following: Movie S1 to S6 Funding: Research reported in this publication was supported by the NSF (EFMA-1830893). We thank R. Schulman for discussions.…”

Section: Supplementary Materialsmentioning

confidence: 99%

Untethered unidirectionally crawling gels driven by asymmetry in contact forces

et al. 2022

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Reversible thermoresponsive hydrogels, which swell and shrink (deswell) in the temperature range of 30° to 60°C, provide an attractive material class for operating untethered soft robots in human physiological and ambient conditions. Crawling has been demonstrated previously with thermoresponsive hydrogels but required patterned or constrained gels or substrates to break symmetry for unidirectional motion. Here, we demonstrate a locomotion mechanism for unidirectionally crawling gels driven by spontaneous asymmetries in contact forces during swelling and deswelling of segmented active thermoresponsive poly( N -isopropylacrylamide) (pNIPAM) and passive polyacrylamide (pAAM) bilayers with suspended linkers. Actuation studies demonstrate the consistent unidirectional movement of these gel crawlers across multiple thermal cycles on flat, unpatterned substrates. We explain the mechanism using finite element simulations and by varying experimental parameters such as the linker stiffness and the number of bilayer segments. We elucidate design criteria and validate experiments using image analysis and finite element models. We anticipate that this mechanism could potentially be applied to other shape-changing locomotors.

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“…However, hydrogels can still be applied to underwater robots to provide some auxiliary functions, such as stealth, buoyancy control, and so on. [119,120]…”

Section: Responsive Hydrogel Actuationmentioning

confidence: 99%

Soft Underwater Swimming Robots Based on Artificial Muscle

Wang

Zhang

et al. 2022

Adv Materials Technologies

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Hence, the exploration and exploitation of marine resources are crucial to human development. However, due to the deep sea's low temperature, high pressure, and complex fluid environment, it is difficult for human beings to easily investigate and work there. As a result, only 5% of Earth's oceans have been explored. Fortunately, thanks to recent rapid developments in science and technology, underwater robotics has seen explosive growth, giving humans a powerful tool to explore the world's oceans, which are expected to play a key role in the underwater rescue, submarine inspection, and hydrological monitoring. [2,3] Recently, with the fast development of bionic technology, [4][5][6][7][8][9] advanced underwater experimental platforms, [10][11][12][13][14] and computational science, [15][16][17][18][19][20] researchers have a deeper understanding of the swimming mechanism of aquatic organisms, which has promoted the explosive growth of underwater robots. [21][22][23][24][25] For example, Zhang et al. [26] developed a gliding robotic fish for long-duration monitoring of underwater environments by combining underwater gliders and robotic fish. Yu et al. [27] developed a biomimetic robot dolphin that, by controlling the pitch angle and swimming speed, could successfully jump out of the water. Lauder and coworkers [28] designed a fast-swimming robot tuna that, through the high-frequency oscillation of the caudal fin, could achieve a maximum tail beat frequency of 15 Hz, which corresponds to a swimming speed of 4.0 body lengths per second (BL S −1 ). However, most underwater robots are driven by motors that are bulky in structure and lack essential safety. In the execution of underwater missions, it is not only easy to cause harm to marine organisms, but it is also difficult to complete required tasks due to poor overall flexibility. Moreover, a rigid robot body driven by a motor suffers from high noise output and a low battery energy conversion rate, meaning that the robot is unable to realize long-term and long-distance tasks. A high noise output can also expose the position of the underwater robot. Overall, the shortcomings of rigid robotic fish significantly restrict application at sea. It is an urgent need to develop high-performance underwater swimming robots with new propulsion methods and bionic structures. Benefiting from the rapid development of materials science and intelligent manufacturing, soft underwater swimming robots have become a hot topic of research. Compared with With the increasing requirements of underwater missions and the rapid development of soft robotics technologies, soft underwater swimming robots have become a hot topic of research due to their low noise, high flexibility, and high environmental adaptability. In the past 10 years, research into soft underwater robots based on artificial muscle actuation has made considerable progress. Herein, a comprehensive survey on recent advances in soft underwater swimming robots based on different actuation methods is reviewed systematically, includi...

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Poly(N-isopropylacrylamide) Hydrogel for Diving/Surfacing Device

Cited by 10 publications

References 19 publications

Preparation and Properties of Temperature-Sensitive P(NIPAM-AM) Nano–Microspheres in Enhanced Oil Recovery

Preparation and Properties of Temperature-Sensitive P(NIPAM-AM) Nano–Microspheres in Enhanced Oil Recovery

Untethered unidirectionally crawling gels driven by asymmetry in contact forces

Soft Underwater Swimming Robots Based on Artificial Muscle

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