Zhang Katherine, Feng Wuxiang, Jin Congrui
Department of Mechanical Engineering, Binghamton University, Binghamton, NY, 13902, USA.
Materials Science and Engineering Program, Binghamton University, Binghamton, NY, 13902, USA.
MethodsX. 2019 Dec 19;7:100779. doi: 10.1016/j.mex.2019.100779. eCollection 2020.
Hydrogels are polymeric materials which can swell in water and retain a significant fraction of water within their structure without dissolving in water. Swelling rate is one of the most important properties of hydrogels. To measure the swelling rate, the profile of swelling capacity versus time of a hydrogel sample is obtained by performing free-absorbency capacity measurements at consecutive time intervals. Traditionally, either the tea-bag method, the sieve method, or the filtration method is used for the free-absorbency capacity measurements depending on the amount of the available sample and the desired precision. However, each method has its own systematic drawbacks. In this paper, a novel method called sieve filtration method is proposed for the measurement of the swelling rate of hydrogels. A protocol for this method is described in detail. The measurement results obtained from the proposed method and the traditional methods are compared. The proposed method has the following advantages over the traditional methods: •It is more efficient than the traditional methods due to full contact of the hydrogel powders with water or aqueous solution as well as fast and complete removal of excessive fluid from the water-absorbed gel.•It enables repeatable and reproducible measurement of the swelling rate of hydrogels.•It is easy to implement, suitable for various types of hydrogels and aqueous solutions; and it requires small amounts of sample, minimal technical skill, and inexpensive equipment.
水凝胶是一种聚合材料，它能在水中溶胀，并在其结构中保留相当一部分水而不溶于水。溶胀速率是水凝胶最重要的特性之一。为了测量溶胀速率，通过在连续的时间间隔内进行自由吸收容量测量，获得水凝胶样品的溶胀容量随时间变化的曲线。传统上，根据可用样品的量和所需的精度，自由吸收容量测量可采用茶包法、筛网法或过滤法。然而，每种方法都有其自身的系统缺陷。本文提出了一种称为筛网过滤法的新方法来测量水凝胶的溶胀速率。详细描述了该方法的实验方案。比较了该方法与传统方法的测量结果。与传统方法相比，该方法具有以下优点：•由于水凝胶粉末与水或水溶液充分接触，以及能快速、完全地从吸水凝胶中去除多余的液体，因此比传统方法更高效。•它能够对水凝胶的溶胀速率进行可重复和可再现的测量。•它易于实施，适用于各种类型的水凝胶和水溶液；并且所需样品量少，技术要求低，设备成本低。
