Test of the Epstein-Plesset model for gas microparticle dissolution in aqueous media: Effect of surface tension and gas undersaturation in solution
Test of the Epstein-Plesset model for gas microparticle dissolution in aqueous media: Effect of surface tension and gas undersaturation in solution
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DOI：
10.1021/la034930i
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发表时间：
2004-03-30
期刊：
影响因子：
3.9
通讯作者：
Needham, D
中科院分区：
文献类型：
--
作者：
Duncan, PB;Needham, D
来自自由气泡的气体将容易地溶解在水中，这由两个主要因素驱动：水溶液中溶解气体的浓度（欠饱和）和气泡-水界面的表面张力（经由由此产生的气泡中的拉普拉斯超压）。本文分别从实验和理论上研究了这些效应。为了研究表面张力的影响，利用单链和双链表面活性剂来控制和定义微泡在饱和溶液中的界面条件。为了研究欠饱和的影响，固体二硬脂酰磷酸胆碱脂质被用来涂覆的气体微粒，基本上，一个蜡单层，并实现零张力的表面。使用显微操作技术进行实验工作，该技术允许在无限稀释中创建和显微操作单个空气微粒（5-50 μ m半径范围），并在由于溶解过程而损失体积时准确记录颗粒的尺寸。微移液管技术已被证明是一个改进，在其他先前的尝试，以测量溶解时间与3.2%的平均实验误差在气体微粒溶解时间。在各向同性扩散场中研究无限稀释的气体微粒的能力符合Epstein-Plesset模型的理论假设和条件。平均而言，Epstein-Plesset模型对实验测定的溶解时间的预测偏低8.6%，其中考虑了表面张力的影响，表面张力的范围为72至25 mN/m。平均而言，Epstein-Plesset模型将溶解时间高估了8.2%，其中考虑了表面张力为零（零拉普拉斯压力）且气体饱和度范围为70%至100%的微粒的欠饱和效应。与文献中以前的尝试相比，本文更适当和准确地测试了单个微泡和空气填充微粒在水溶液中溶解的Epstein-Plesset模型。
The gas from a free air bubble will readily dissolve in water, driven by two main factors: the concentration (undersaturation) of dissolved gas in the aqueous solution and the surface tension of the gas bubble-water interface via a Laplace overpressure in the bubble that this creates. This paper experimentally and theoretically investigates each of these effects individually. To study the effects of surface tension, single- and double-chain surfactants were utilized to control and define interfacial conditions of the microbubble in saturated solution. To study the effect of undersaturation, solid distearoylphosphocholine lipid was utilized to coat the gas microparticle with, essentially, a wax monolayer and to achieve zero tension in the surface. The experimental work was performed using a micromanipulation technique that allows one to create and micromanipulate single air microparticles (5-50 mum radius range) in infinite dilution and to accurately record the size of the particle as it loses volume due to the dissolution process. The micropipet technique has shown to be an improvement over other previous attempts to measure dissolution time with a 3.2% average experimental error in gas microparticle dissolution time. An ability to study a gas microparticle in infinite dilution in an isotropic diffusion field is in line with the theoretical assumptions and conditions of the Epstein-Plesset model. The Epstein-Plesset model on average underpredicted the experimentally determined dissolution time by 8.6%, where the effect of surface tension was considered with a range of surface tensions from 72 down to 25 mN/m. The Epstein-Plesset model on average overpredicted the dissolution time by 8.2%, where the effect of undersaturation was considered for a microparticle with zero tension in the surface (zero Laplace pressure) and a range of gas saturations from 70% to 100%. Compared to previous attempts in the literature, this paper more appropriately and accurately tests the Epstein-Plesset model for the dissolution of a single microbubble and an air-filled microparticle in aqueous solution.