Filipecki Jacek, Kocela Agnieszka, Korzekwa Witold
Jan Dlugosz University in Częstochowa, Institute of Physics, Częstochowa, Poland.
Komed Clinic, Częstochowa, Poland.
Polim Med. 2014 Oct-Dec;44(4):255-60.
Polymer materials based on hydrogel and silicone-hydrogel materials are commonly used in ophthalmology. It is important to research the structure of these materials, mainly the prevalence of free volumes.
The study has been conducted in order to determine the presence of free volume gaps in the structure of polymer hydrogel and silicone-hydrogel contact lenses. In addition, to demonstrate differences in the occurrence of free volumes between types of represented contact lenses.
Three different hydrogel and three different silicone-hydrogel polymer contact lenses were used as research material. The study was done by means of positron annihilation lifetime spectroscopy (PALS).
As a result of the performed measurements, a graphical curve resulted which describes the relationship between the number of the annihilation acts in the time function. The study revealed the existence of three τ1, τ2 and τ3 components. Significant changes were observed in the ortho-positronium long life component τ3 and their intensities between the examined polymer contact lenses.
The conducted study using the Tao-Eldrup model indicates the presence of free volume holes in all research materials. The results lead to the following connection: contact lenses of higher oxygen permeability coefficient (silicone-hydrogel contact lenses) have more and larger free volumes than contact lenses of less oxygen permeability coefficient (hydrogel contact lenses).
基于水凝胶和硅水凝胶材料的聚合物材料常用于眼科。研究这些材料的结构很重要，主要是研究自由体积的普遍情况。
进行这项研究是为了确定聚合物水凝胶和硅水凝胶隐形眼镜结构中自由体积间隙的存在情况。此外，还要证明不同类型隐形眼镜自由体积出现情况的差异。
使用三种不同的水凝胶和三种不同的硅水凝胶聚合物隐形眼镜作为研究材料。通过正电子湮没寿命谱（PALS）进行研究。
通过所进行的测量，得到了一条描述湮没行为数量与时间函数关系的图形曲线。该研究揭示了存在三个τ1、τ2和τ3分量。在所研究的聚合物隐形眼镜之间，邻正电子素长寿命分量τ3及其强度观察到了显著变化。
使用陶 - 埃尔德鲁普模型进行的这项研究表明，所有研究材料中都存在自由体积孔。结果得出以下关联：氧透过系数较高的隐形眼镜（硅水凝胶隐形眼镜）比氧透过系数较低的隐形眼镜（水凝胶隐形眼镜）具有更多且更大的自由体积。
