Importance of Substrate Functionality on the Adhesion and Debonding of a Pressure-Sensitive Adhesive under Water
Importance of Substrate Functionality on the Adhesion and Debonding of a Pressure-Sensitive Adhesive under Water
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DOI：
10.1021/acsami.7b13984
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发表时间：
2017-12-06
影响因子：
9.5
通讯作者：
Frechette, Joelle
中科院分区：
文献类型：
--
作者：
Karnal, Preetika;Roberts, Paul;Frechette, Joelle
研究了水性环境对丙烯酸2-乙基己酯-丙烯酸共聚物压敏胶（PSA）粘接性能的影响。我们使用探针粘着力测量伴随着在粘接和脱粘过程中的接触区域的原位成像。在探针粘性测试中，我们使用亲水性（食人鱼和等离子体处理）和疏水性（C-18硅烷化）表面处理来研究探针的表面能对水下粘附力的贡献。在检查接触形成在空气中和水下，我们发现，水的存在下，接触时，导致不同模式的PSA松弛和接触形成。对于所有调查的探针，PSA和探针之间的粘合强度下降时，在水下测量。此外，我们观察到，在剥离过程中的水的存在下有一个更明显的影响PSA的粘合强度时，探测到的亲水性表面，而不是一个疏水性表面。使用指进波长分析，我们估计的PSA在原位的表面能，发现当浸没在水中，PSA具有显着更高的表面能相比，在空气中。因此，结合观察不同模式的接触形成，表面能的增加，和探针的表面能的重要性，我们建议，在水中的粘合强度的降低可以解释由PSA的水合作用和由PSA和探针之间的水缺陷被困。
We investigate the effect of an aqueous environment on the adhesion of a model acrylic pressure-sensitive adhesive (PSA) composed of 2-ethylhexyl acrylate-co-acrylic acid. We use probe-tack adhesion measurements accompanied by in situ imaging of the contact region during bonding and debonding. Within the probe-tack tests, we use both hydrophilic (piranha and plasma treatment) and hydrophobic (C-18-silanization) surface treatments to investigate the contribution of the probe's surface energy on the underwater adhesion. In examining contact formation in air and underwater, we find that the presence of water when contact is made leads to different modes of PSA relaxation and contact formation. For all probes investigated, the adhesive strength between the PSA and the probe decreases when measured underwater. Additionally, we observe that the presence of water during debonding has a more pronounced effect on the adhesive strength of the PSA when probed by a hydrophilic surface as opposed to a hydrophobic surface. Using fingering wavelength analysis, we estimate the surface energy of the PSA in situ and find that when submerged in water, the PSA has a significantly higher surface energy compared to in air. Therefore, combining the observation of different modes of contact formation, the increase in surface energy, and the importance of the surface energy of the probe, we suggest that the decrease in adhesive strength in water can be explained by the hydration of the PSA and by trapped water defects between the PSA and the probe.