Captive bubble method

<p>The captive bubble method is a method for measuring the <a href="/facts/Contact_angle/dSJcI5KN">contact angle</a> between a <a href="/facts/Liquid/t9GkLWzt">liquid</a> and a <a href="/facts/Solid/hj5UsXno">solid</a>, by using drop shape analysis. In this method, a bubble of <a href="/facts/Air/hQ95Jznz">air</a> is injected beneath a solid, the surface of which is located in the <a href="/facts/Liquid/t9GkLWzt">liquid</a>, instead of placing a <a href="/facts/Drop_(liquid)/m4kuGAgH">drop</a> on the <a href="/facts/Solid/hj5UsXno">solid</a> as in the case of the <a href="/facts/Sessile_drop_technique/zo6XXXJg">sessile drop technique</a>. A <a href="/facts/Liquid/t9GkLWzt">liquid</a> and a <a href="/facts/Solid/hj5UsXno">solid</a> are replaced by using drop shape analysis.
</p><p>The method is particularly suitable for solids with high surface energy, where liquids spread out. <a href="/facts/Hydrogel/kYMJum9P">Hydrogels</a>, such as those that comprise soft <a href="/facts/Contact_lens/0nzxq5Rm">contact lenses</a>, are inaccessible to the standard arrangement; so the captive bubble method is also used in such cases. A contact angle is formed on a smooth, periodically heterogeneous solid surface. Above the solid surface, a liquid drop is submerged in a fluid. The measurement of contact angles usually contributes to the measurement of the surface energy of solids in the industry. Different from other methods of measuring the contact angle, such as the sessile drop technique, the system utilized in the captive bubble method has the fluid bubble attached from below to the solid surface, such that both the liquid bubble and the solid interact with a fluid.
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Captive bubble method open-in-new

Captive bubble method