New method of determining contact angle between monofilament and liquid

Abstract

SynopsisThis paper describes a method to obtain contact angle by observing the shapf of a liquid drop attached to a monofilament. The relations between contact angle and the dimensions of drops are theoretically obtained. Thus, it is possible to calculate the contact angle if drop shape is measured. Through use of this method, the contact angles of epoxy resin on various kinds of monofilamente were measured. It was found that this method has practical utility for measurement of the contact angle between liquid and monofilament.

Droplet on a fiber: geometrical shape and contact angle

“…This shows that the contact angle of a microdroplet on a fiber is a material constant, independent of the geometrical aspect ratio and equal to that on a flat surface. This confirms the choice of constant contact angle in previous works [5], [6]. Now let us further consider the Euler-Lagrange equation (9).…”

“…The wetting shape of a microdroplet on a fiber does not appear as a partial sphere as that on a flat surface. Within the framework of Laplace's formula of surface tension and Young's equation of wetting angle, Yamaki and Katayama [5] first studied the shape of a microdroplet on a fiber by solving the governing equation numerically. Carroll [6] considered this problem through an analytic approach, and he found that the droplet shape could be expressed as the combination of Legendre's elliptical functions of the first and second kinds.…”

“…Different from the previous works [5]- [8], we begin with the free energy variation of a microdroplet on a homogenous cylindrical fiber. Without the aid of any further assumptions, we derive the exact governing equation and correct boundary conditions governing the geometrical shape, fiber wetting length, and contact angle of the microdroplet.…”

The Influence of Pet Fibres Surface Enzymatic Modification on the Selected Properties

“…The contact angle of fibres was measured by the numerical method, using as a base of logarithm Laplace's equation, converted by Yamaki and Katayama [41] into a differential form that takes into account the axial-symmetrical shape of the drop profile and the cylindrical fibre shape. Two liquids were used: α-bromonaphthalene and glycerine.…”

“…The change in the surface of PET fibres after modification with esterases from hydrophobic to hydrophilic resulted also in the improvement in the resistance to soiling and oil-soil release [19] as well as dyeability with disperse dyes [1,8,32,41].…”