Probing particle structure in waterborne pressure-sensitive adhesives with atomic force microscopy.
Probing particle structure in waterborne pressure-sensitive adhesives with atomic force microscopy.
复制标题
用原子力显微镜探测水性压敏粘合剂中的颗粒结构。
DOI：
10.1016/j.jcis.2006.11.036
复制
发表时间：
2007
影响因子：
9.9
通讯作者：
J. Keddie
中科院分区：
文献类型：
--
作者：
C. Lei;K. Ouzineb;O. Dupont;J. Keddie
需要了解由水性聚合物胶体获得的压敏粘合剂 (PSA) 薄膜的纳米结构，以便将其与性能相关联。丙烯酸水性压敏胶薄膜的间歇接触原子力显微镜 (AFM) 识别出两种成分，这可归因于聚合物和血清中的固体（主要是表面活性剂）。研究发现，当平均 AFM 攻丝力 Fav 相对较低时，聚合物颗粒呈现凹形。但当 Favis 较高时，颗粒看起来呈凸形。这一观察结果可以通过随敲击幅度和 Fav 变化的两个组件的压痕深度差异引起的高度伪影来解释。为了实现聚合物和血清成分之间的最大对比度，应设置 Fav 以使压痕深度尽可能不同。与高度图像不同，PSA 的相差图像在所应用的敲击条件范围内没有显示对比度反转。因此，相图可以根据粘弹性特性可靠地区分 PSA 的两种成分。在室温下干燥的薄膜表面，在薄膜永久凹陷的局部区域发现了血清成分。
There is a need to know the nanostructure of pressure-sensitive adhesive (PSA) films obtained from waterborne polymer colloids so that it can be correlated with properties. Intermittent-contact atomic force microscopy (AFM) of an acrylic waterborne PSA film identifies two components, which can be attributed to the polymer and the solids in the serum (mainly surfactant). It is found that when the average AFM tapping force, Fav, is relatively low, the polymer particles appear to be concave. But when Favis higher, the particles appear to have a convex shape. This observation is explained by a height artefact caused by differences in the indentation depths into the two components that vary with the tapping amplitude and Fav. To achieve the maximum contrast between the polymer and serum components, Favshould be set such that the indentation depths are as different as possible. Unlike what is found for the height images, the phase contrast images of the PSA do not show a reversal in contrast over the range of tapping conditions applied. The phase images are thus reliable in distinguishing the two components of the PSA according to their viscoelastic properties. At the surface of films dried at room temperature, the serum component is found in localized regions within permanent depression into the film.