| 초록 |
With the aim of checking the validity of the novel method to evaluate the adhesion properties between inorganic materials with high surface energy, adhesion properties between inorganic material (indium tin oxide, ITO) and model surfaces with various surface energy were investigated by using ITO-coated AFM tip and JKR lens. AFM tip and JKR lens were modified by rf magnetron sputtering method with ITO. The work of adhesion was estimated by using the force-displacement curve (AFM) and Johnson-Kendall-Roberts (JKR) apparatus. These values were compared with the theoretical values obtained from macroscopic contact angle measurements. In the case of force-displacement curve, the measured adhesive forces were found to agree well with predictions of the Derjaguin-Muller-Toporov (DMT) theory. However, the work of adhesions obtained from JKR apparatus are about one third of the theoretical values because the rigid layer (ITO) is coated on the PDMS lens. The multiplying factor which is the ratio of the surface modulus to the bulk modulus of ITO-coated PDMS lens was obtained by the slope of the attracting part of force-displacement curve. These two methods using AFM and JKR apparatus can be applied in the evaluation of the work of adhesion between inorganic materials with high surface energy such as metal and metal oxide surfaces because contact angle measurements cannot be used to probe high free energy surfaces that are wet by most liquids. |
