Surfaces /Interfaces
“In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3— for example, the surface of a ball. On the other hand, there are surfaces, such as the Klein bottle, that cannot be embedded in three-dimensional Euclidean space without introducing singularities or self-intersections.”
“To say that a surface is "two-dimensional" means that, about each point, there is a coordinate patch on which a two-dimensional coordinate system is defined. For example, the surface of the Earth is (ideally) a two-dimensional sphere, and latitude and longitude provide coordinates on it.”
“Surfaces find application in physics, engineering, computer graphics, and many other disciplines, primarily when they represent the surfaces of physical objects. For example, in analyzing the aerodynamic properties of an airplane, the central consideration is the flow of air along its surface.”
(Wikipedia, Surfaces, 11/18/2010)
Adhesion
Fluorinated Surfaces
Fluorocompound Surface Treatments
Materials
Plasma Treatments
Superhydrophobic Surfaces
Superoleophobic Surfaces
Surface Grafting
Recent US Patents
11/29/2011
8,066,824
Covalent modification of metal surfaces
Breitenkamp et al of Intezyme Technologies made metal surfaces hydrophilic with oxygen and water plasmas. These hydrophilic surfaces were further treated with dehydration or condensation. (RDC 12/5/2011)
11/29/2011
8,066,819
Method of removing organic materials from substrates
Waleh and Levenson of Best Label, California, used water-free, gaseous sulfur trioxide to remove various organic coatings, films, layers and residues from the surface of a substrate when used in conjunction with certain other physical and chemical treatments applied at the appropriate time during the process. (RDC 12/5/2011)
9/7/2010
7,790,807
Fluorocarbon terminated oligo- and poly-carbonates as surface modifiers
Brunner et al of Ciba Speciality Chemicals has developed fluorocarbon polycarbonates as surface modifiers. By making surfaces hydrophobic they can be made "easy to clean", "self-cleaning" "antisoiling", "soil-release" "antigraffiti", "oil resistance", "solvent resistance", "chemical resistance", "self lubricating", "scratch resistance", "low moisture absorption" and "hydrophobic" surface.(RDC 12/4/2010)
Recent Journal Articles
A Superhydrophobic to Superhydrophilic In Situ Wettability Switch of Microstructured Polypyrrole Surfaces
(718–723)Macromolecular Rapid Communications 32 #9-10 (2011)
Chang and Hunter of the Massachusetts Institute of Technology, Massachuesetts, present an electrochemical layered system that allows for the fast, in situ wettability switch of microstructured PPy upon the application of an electric stimulus. We have eliminated the need for PPy to be immersed in an electrolyte to switch between wetting states, laying the groundwork for PPy to be used as a viable material in many applications, including microfluidics or smart textiles. The PPy surface was switched from the superhydrophobic state (contact angle = 159) to the superhydrophilic state (contact angle = 0) in 3 s. A wettability gradient was also created on a PPy surface using the layered system, causing a 3 µL droplet to travel approximately 2 mm in 0.8 s. (RDC 5/26/2011)
What are the differences of polymer surface relaxation from the bulk?
(81-86) Chinese Journal of Polymer Science 29, #1 (2011)
Mann et al studied polymer surface relaxation of a polyimide surface by first aligning the surface molecules in a liquid crystal cell. The relaxation temperature at which the liquid crystals lose their orientation depends on the film thickness of the polyimide. A quantitative linear relationship between the relaxation temperature and reciprocal of the film thickness can be observed. Furthermore, different topologies of the rubbed and relaxed thin films were amplified using the polyethylene decoration method and observed using atomic force microscopy. (RDC 12/3/2010)
11/26/2010
Surface glass transition of miscible amorphous polymers blends
(1757-1761) Colloid and Polymer Science 288 #18 (2010)
Boiko of the Russian Academy of Sciences measured the surface glass transition temperature of the bulk samples of miscible blends formed of amorphous polystyrene (PS) and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) blends on the basis the temperature transition “occurrence of autoadhesion–nonoccurrence of autoadhesion” by employing a lap-shear joint mechanical testing method. (RDC 11/23/2010)
11/19/2010|
Plasma Surface Fluorination of Hydrogel Materials—Coating Stability and in vitro Biocompatibility Testing
(164 – 182) Soft Materials 8, #2 (2010).
Bozukova et al attempted to form hydrophobic perfluorinated coatings on the surfaces of hydrophilic poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) [poly(HEMA-co-MMA)] substrates, used for the intraocular lenses. Generally, the results showed poor stability of the coating and call into question its covalent grafting to the surface. (RDC 11/20/2010)
Review Articles
11/19/2010
Reinforcement of adhesion and development of morphology at polymer–polymer interface via reactive compatibilization: A review
(pages 2273–2286) Polymer Engineering & Science 50 #12 (2010)
Jiand, Wu and Guo of Sichuan University, China review interfacial copolymerization and its effect ofn interfacial adhesion and morphology. (RDC 11/19/2010)