Towards the Determination of Surface Energy at the Nanoscale: A Further Assessment of the AFM-Based Approach

Abstract

Towards the validation of the atomic force microscopy-based approach to the determination of surface energy at the nanometer scale, this paper explores the applicability of the technique by comparing atomic force microscopy-derived surface energy values with those from conventional contact angle measurements from a range of self-assembled organosilane structures ((3-aminopropyl)triethoxysilane, (3-glycidoxypropyl)trimethoxysilane, 3-(triethoxysilyl)propylsuccinic anhydride and trimethoxy(propyl)silane) and also from films of an ultra-low-surface-energy polymer, poly(1H,1H,2H,2H-perfluorodecyl methacrylate). The close agreement between the two sets of data indicates the validity of the AFM method, while unique attributes are indicated by the high resolution (ca. 1000 atoms) that is inherent to the approach and by the capability to study materials that are not compatible with the probing liquids used for goniometric determinations.

Probing polydopamine adhesion to protein and polymer films: microscopic and spectroscopic evaluation

“…Surface energies of substrates (c s ) were calculated from the contact angles and the interfacial energies of the three probe liquids using the Good and Oss [51] three-liquid formula (Eqs. 1, 2 and 3), using an inhouse Visual Basic program as per Lamprou et al [52]. Contact angle measurements were performed after AFM or on alternate surfaces in order to ensure that the drops dip did not affect the surface morphology.…”

Isatin thiosemicarbazone-blended polymer films for biomedical applications: surface morphology, characterisation and preliminary biological assessment

“…Experiments were repeated at least 3 times on different surfaces. 29 via an in-house Visual Basic program 28 .…”

“…Derivatives used at 10 µM except for surface I which was used at 50 µM to investigate the effect of a higher concentration. EG; γL 48.0 mN m -1 at 20 °C) (surface tension γL values from Lamprou et al28 ) on surfaces were measured with a Krüss DSA30B contact angle goniometer. Advancing angles (θA) were obtained from both the left and right side of each drop at 10-20 s after drop placement.…”

Experimental and computational examination of anastellin (FnIII1c)–polymer interactions

“…At least 2 repeats were made for each surface with 3 drops per sample, resulting in at least 12 measurements per sample. Using these contact angle values, the surface energies were calculated using a Visual Basic application developed by Lamprou et al 36 based on the formula proposed by Good and Oss. 37…”