The wettability and micro-equilibrium of different essence liquids to alkali-treated kapok fiber

2021 ◽  
pp. 004051752110320
Author(s):  
Liyao Cao ◽  
Yanfang Xu ◽  
Kaifang Xie ◽  
Fumei Wang ◽  
Guangbiao Xu

Kapok fiber is a natural hollow fiber that has superior biocompatibility and biodegradability and is naturally antibacterial. Because of its unique properties, it has great potential in the application of postoperative repair dressings. The wettability and micro-equilibrium of kapok fibers play a critical role in dressing applications. In this study, the critical adhesion volume and adhesion energy of essence liquid to alkali-treated kapok fiber (AKF) were quantitatively calculated to explore the wettability and micro-equilibrium through the equilibrium wetting theory. Meanwhile, the three-phase contact line (TCL) structure was described. The results showed that the critical adhesion volumes of the three types of essence liquid for AKF were 3.45, 3.81, and 4.12 μL, respectively. Moreover, the critical volumes and low error rates derived from the equilibrium wetting theory were 3.41 μL and 1.16%, 3.99 μL and 4.51%, and 4.60 μL and 10.43%, respectively. Therefore, the critical volume of adhesion could be well calculated by the theoretical model. The average adhesive energies of essence liquid to the AKF were 0.38, 0.45, and 0.56 J, respectively, caused by the difference in liquids properties. The TCL showed a mechanical lock and bonding points at both ends because of the curvature difference and higher surface energy. These results are proposed to inspire the design of a liquid carrier of kapok fibers based on the fiber network structure.

1999 ◽  
Vol 96 (9) ◽  
pp. 1335-1339 ◽  
Author(s):  
ALAN E. VAN GIESSEN, DIRK JAN BUKMAN, B.

2020 ◽  
Vol 55 (1) ◽  
pp. 32-37
Author(s):  
A. Yu. Vorob’ev ◽  
V. A. Nebol’sin ◽  
N. Swaikat ◽  
V. A. Yuriev

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4215
Author(s):  
Hiromi Kimura ◽  
Go Fuseya ◽  
Satoshi Takeya ◽  
Akihiro Hachikubo

Knowledge of carbon isotope fractionation is needed in order to discuss the formation and dissociation of naturally occurring CO2 hydrates. We investigated carbon isotope fractionation during CO2 hydrate formation and measured the three-phase equilibria of 12CO2–H2O and 13CO2–H2O systems. From a crystal structure viewpoint, the difference in the Raman spectra of hydrate-bound 12CO2 and 13CO2 was revealed, although their unit cell size was similar. The δ13C of hydrate-bound CO2 was lower than that of the residual CO2 (1.0–1.5‰) in a formation temperature ranging between 226 K and 278 K. The results show that the small difference between equilibrium pressures of ~0.01 MPa in 12CO2 and 13CO2 hydrates causes carbon isotope fractionation of ~1‰. However, the difference between equilibrium pressures in the 12CO2–H2O and 13CO2–H2O systems was smaller than the standard uncertainties of measurement; more accurate pressure measurement is required for quantitative discussion.


Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 52
Author(s):  
Xiang He ◽  
Sijia Wang ◽  
Bingjian Zhang

Dew is a common but important phenomenon. Though water is previously considered to be a threat to earthen heritage sites, artificial dew is showing potential in relic preservation. A model of dew prediction on earthen sites will be essential for developing preventive protection methods, but studies of dew formation processes on relics are limited. In this study, a two parameter model is proposed. It makes approximations according to the features of earthen heritage sites, assuming that a thin and steady air layer exists close to the air–solid interface. This semi-theoretical model was based on calculations of the mass transfer process in the air layer, and was validated by simulations of laboratory experiments (R > 0.9) as well as field experiments. Additionally, a numerical simulation, performed by the commercial software COMSOL, confirmed that the difference between fitting parameter δ and the thickness of assumed mass transfer field was not significant. This model will be helpful in developing automatic environmental control systems for stabilizing water and soluble salts, thus enhancing preventive protection of earthen heritage sites.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Demissie Jobir Gelmecha ◽  
Ram Sewak Singh

AbstractIn this paper, the rigorous derivations of generalized coupled chiral nonlinear Schrödinger equations (CCNLSEs) and their modulation instability analysis have been explored theoretically and computationally. With the consideration of Maxwell’s equations and Post’s constitutive relations, a generalized CCNLSE has been derived, which describes the evolution of left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) components propagating through single-core nonlinear chiral fiber. The analysis of modulation instability in nonlinear chiral fiber has been investigated starting from CCNLSEs. Based on a theoretical model and numerical simulations, the difference on the modulation instability gain spectrum in LCP and RCP components through chiral fiber has been analyzed by considering loss and chirality into account. The obtained simulation results have shown that the loss distorts the sidebands of the modulation instability gain spectrum, while chirality modulates the gain for LCP and RCP components in a different manner. This suggests that adjusting chirality strength may control the loss, and nonlinearity simultaneously provides stable modulated pulse propagation.


2009 ◽  
Vol 131 (12) ◽  
Author(s):  
Enno Wagner ◽  
Peter Stephan

In a special boiling cell, vapor bubbles are generated at single nucleation sites on top of a 20μm thick stainless steel heating foil. An infrared camera captures the rear side of the heating foil for analyzing the temperature distribution. The bubble shape is recorded through side windows with a high-speed camera. Global measurements were conducted, with the pure fluids FC-84 and FC-3284 and with its binary mixtures of 0.25, 0.5, and 0.75mole fraction. The heat transfer coefficient (HTC) in a binary mixture is less than the HTC in either of the single component fluid alone. Applying the correlation of Schlünder showed good agreement with the measurements (1982, “Über den Wärmeübergang bei der Blasenverdampfung von Gemischen,” Verfahrenstechnik, 16(9), pp. 692–698). Furthermore, local measurements were arranged with high lateral and temporal resolution for single bubble events. The wall heat flux was computed and analyzed, especially at the three-phase-contact line between liquid, vapor, and heated wall. The bubble volume and the vapor production rate were also investigated. For pure fluids, up to 50–60% of the latent heat flows through the three-phase-contact region. For mixtures, this ratio is clearly reduced and is about 35%.


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