Simple measurement of surface free energy using a web cam
نویسندگان
چکیده
Neste trabalho, descrevemos uma experiência simples e pedagógica para medir a energia livre de superf́ıcie (SFE) que é um tema dominante no ensino da F́ısica, a ńıvel de estudos de graduação e pós-graduação. A vantagem desta experiência baseia-se na simplicidade dos materiais utilizados, ou seja, produtos de baixo custo e não prejudiciais, como água, glicerol, etileno glicol e propanol, que oferecem uma boa oportunidade para discutir pedagogicamente conceitos básicos, mas relevantes sobre fenómenos de superf́ıcie. Como exemplo, medidas de ângulo de contacto foram utilizadas para estimar a SFE e a molhabilidade de diferentes superf́ıcies sólidas, tais como o vidro e o politetrafluoretileno (PTFE, Teflon R ⃝). Palavras-chave: práticas pedagógicas, energia livre de superf́ıcie, ângulo de contacto.
منابع مشابه
Novel Poly (glycerol-adipate) Polymers Used for Nanoparticle Making: A Study of Surface Free Energy
Nanoparticles made of biodegradable polymers has become the best approach for nanoparticle making due to their compatibility with the human body. New glycerol adipate polymers with hydroxyl group substituted with different percent of acyl group, sited as figures within the abbreviated name in the text, and triptophan were synthesized and proposed to be used in the preparction of dexamethason ph...
متن کاملNovel Poly (glycerol-adipate) Polymers Used for Nanoparticle Making: A Study of Surface Free Energy
Nanoparticles made of biodegradable polymers has become the best approach for nanoparticle making due to their compatibility with the human body. New glycerol adipate polymers with hydroxyl group substituted with different percent of acyl group, sited as figures within the abbreviated name in the text, and triptophan were synthesized and proposed to be used in the preparction of dexamethason ph...
متن کاملNonlocal Analysis of Longitudinal Dynamic Behavior of Nanobars with Surface Energy Effect
Due to considerable stored energy in surfaces of nano-scales in comparison with the stored energy in their bulk, considering the surface energy is necessary for the analysis of various behaviors of nano-scales for more precise design and manufacturing. In this article, the longitudinal dynamic behavior of nanobars in the presence of the surface energy parameters is studied. To this end, the lon...
متن کاملApplication of SCB Test and Surface Free Energy Method in Evaluating Crack Resistance of SBS Modified Asphalt Mixes
Cohesion properties of the binder matrix within asphalt mixes and adhesion characteristics of the asphalt binder and aggregate particles are the two major mechanisms resisting against cracking in asphalt mixes. This study is focused on estimating crack resistance of asphalt mixes at intermediate temperatures through evaluation of cohesion and adhesion properties of binder-aggregate systems usin...
متن کاملNb2O5 Nanoparticles Synthesis by Chemical Surfactant-Free Methods: ltrasonic Assisted Approach
In this study, spherical Nb2O5 nanoparticles were synthesized by a novel chemical method as a simple, robust, surfactant-free, non-toxic and widely applicable approach. In order to investigate the effect of initial concentration on particle sizes, nanoparticles with different initial concentration were synthesized. Ultrasonic assisted method was applied and the effects of ultrasonic treat...
متن کامل