This is the fourth volume in the series "Advances in Contact Angle, Wettability and Adhesion" initiated to consolidate information and provide commentary on certain recent research aspects dealing with this important topic. Its predecessor Volumes 1, 2 and 3 were published in 2013, 2015 and 2018 respectively. This new book comprising 14 research and review articles is divided into four parts: Part 1: Contact Angle and Wettability Aspects; Part 2: Surface Free Energy and Surface Tension Determination; Part 3: Applied Aspects. The topics covered include: Contact Angle Determination of Talc Powders from Heat of ImmersionSurface Wetting at Macro and NanoscaleWettability of Wood Surfaces with Waterborne Acrylic Lacquer Stains Modulated by DBD Plasma Treatment in Air at Atmospheric PressureWettability of Ultrafiltration Membranes     Determination of the Surface Free Energy of Solid Surfaces: Can the Best Model be FoundSurface Free Energy Characterization of Talc PowdersDetermination of the Surface Free Energy of Skin and the Factors Affecting it by the Contact Angle MethodDetermination of Surface Tension Components of Aqueous Solutions using Fomblin HC/25 R Perfluoropolyether Liquid Film as a Solid SubstrateEnhancing the Wettability of Polybenzimidazole (PBI) to Improve Fuel Cell PerformanceEvaluation of Sebum Resistance for Long-Wear Face Make-Up Products Using Contact Angle MeasurementsContact Angle Hysteresis of Pressure-Sensitive Adhesives due to Adhesion Tension RelaxationThe Potential of Surface Nano-Engineering and Superhydrophobic Surfaces in Drag ReductionLaser Surface Engineering of Polymeric Materials for Enhanced Mesenchymal Stem Cell Adhesion and GrowthSisal-Green Resin Interfaces in Green Composites.