Syntheses and characterization of new photoresponsive surfactants, N-(azobenzene-4-oxy-2-hydroxypropyl)-N-(alkyloxy-2-hydroxypropyl) aminopropyl sulfonic acid sodium salt

Nam, Seok Hyeon; Choi, Young Jin; Kim, Young Wun; Jun, Kil-Woung; Jeong, Noh Hee; Oh, Seong‐Geun; Kang, Ho Cheol

doi:10.1016/j.jiec.2020.07.013

Cited by 9 publications

(2 citation statements)

References 51 publications

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“…Figure 3 a shows the surface tensions of the photo-responsive surfactant solution with different concentrations of the AzoC 8 F 15 molecules with trans - and cis -forms, reflecting the change in surface activity of AzoC 8 F 15 molecules in DMAC solution under different light irradiations [ 32 ]. As can be observed, the surface tensions of AzoC 8 F 15 solutions with both trans - and cis -form decreased obviously with an increase in the surfactant concentration, and eventually reached the plateau value around the critical micelle concentration (CMC) of surfactant [ 33 ]. As the concentration of the solution increased, due to the different alignments of the AzoC 8 F 15 molecules with trans - and cis -forms at the gas-liquid interface, the surface tension of the surfactant solution shows significant variation under different light irradiations: when the surfactant concentration is 0.01 mol/L, the surface tensions of AzoC 8 F 15 solutions with trans - and cis -forms are 22.79 and 33.63 mN/m, respectively, where the surface tension difference (Δγ = γ cis − γ trans ) reached a maximum (Δγ max = 10.94 mN/m).…”

Section: Resultsmentioning

confidence: 99%

Bioinspired Photo-Responsive Liquid Gating Membrane

Zhang

Lei

et al. 2022

Biomimetics

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Stomata in the plant leaves are channels for gas exchange between the plants and the atmosphere. The gas exchange rate can be regulated by adjusting the opening and closing of stoma under the external stimuli, which plays a vital role in plant survival. Under visible light irradiation, the stomata open for gas exchange with the surroundings, while under intense UV light irradiation, the stomata close to prevent the moisture loss of plants from excessive transpiration. Inspired by this stomatal self-protection behavior, we have constructed a bioinspired photo-responsive liquid gating membrane (BPRLGM) through infusing the photo-responsive gating liquid obtained by dissolving the azobenzene-based photo-responsive surfactant molecules (AzoC8F15) in N,N-Dimethylacetamide (DMAC) into nylon porous substrate, which can reversibly switch the open/closed states under different photo-stimuli. Theoretical analysis and experimental data have demonstrated that the reversible photoisomerization of azobenzene-based surfactant molecules induces a change in surface tension of the photo-responsive gating liquid, which eventually results in the reversible variation of substantial critical pressure for gas through BPRLGM under alternating UV (PCritical (off)) and visible (PCritical (on)) light irradiations. Therefore, driven by a pressure difference ΔP between PCritical (on) and PCritical (off), the reversible switches on the open/closed states of this photo-responsive liquid gating membrane can be realized under photo-stimuli. This bioinspired membrane with switchable open/closed liquid gating performance under photo-stimuli has the opportunity to be used in the precise and contactless control of microfluidics.

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Section: Resultsmentioning

confidence: 99%

Bioinspired Photo-Responsive Liquid Gating Membrane

Zhang

Lei

et al. 2022

Biomimetics

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“…“TSI” is called the stability index and calculated as in Equation (1):

where x i is the average value of the backscattered light intensity per scan; x BS is the average value of x i ; and n is the number of scans. The smaller the TSI value, the better the stability of the emulsion [ 56 , 57 , 58 , 59 ].…”

Section: Methodsmentioning

confidence: 99%

The Synergistic Effects between Sulfobetaine and Hydrophobically Modified Polyacrylamide on Properties Related to Enhanced Oil Recovery

Sun

Hu²,

Han

et al. 2023

Molecules

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In order to explore the mechanism responsible for the interactions in the surfactant–polymer composite flooding and broaden the application range of the binary system in heterogeneous oil reservoirs, in this paper, the influences of different surfactants on the viscosity of two polymers with similar molecular weights, partially hydrolyzed polyacrylamide (HPAM) and hydrophobically modified polyacrylamide (HMPAM), were studied at different reservoir environments. In addition, the relationship between the surfactant–polymer synergistic effects and oil displacement efficiency was also investigated. The experimental results show that for HPAM, surfactants mainly act as an electrolyte to reduce its viscosity. For HMPAM, SDBS and TX-100 will form aggregates with the hydrophobic blocks of polymer molecules, reducing the bulk viscosity. However, zwitterionic surfactant aralkyl substituted alkyl sulfobetaine BSB molecules can build “bridges” between different polymer molecules through hydrogen bonding and electrostatic interaction. After forming aggregates with HMPAM molecules, the viscosity will increase. The presence of two polymers all weakened the surfactant oil–water interfacial membrane strength to a certain extent, but had little effect on the interfacial tension. The synergistic effect of the “bridge” between HMPAM and BSB under macroscopic conditions also occurs in the microscopic pores of the core, which has a beneficial effect on improving oil recovery.

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