Thin-film technologies self-assembled films

The formation of two- and three-dimensional phases on electrode surfaces is a topic of central importance in interfacial electrochemistry. It is of relevance not only to hmdamental problems, such as the formation of ionic and molecular adsorbate films, but also to areas of great technological interest, such as thin-film deposition, self-assembly of monolayers, and passivation. So far, phase formation in electrochemical systems has been studied predominantly by kinetic measurements using electrochemical or spectroscopic techniques. In order to understand and control these processes as well as the resulting interface structure better, however, improved... 

In the 20 years since it was established, LbL assembly has come a long way from the scientific curiosity it once was. Today, it is competing favorably with rival technologies for the preparation of organic thin films (e.g., LB films and self-assembled mono-layers (SAMs)) and surface functionalization (e.g., chemical... 

Organic thin film (monolayer) coatings can be applied on oxide or metal (typically gold)-coated probe tips following recipes for self-assembled monolayer depositions that were adjusted for AFM probe technology. These probes are also commercially available and are useful to ensure known surface chemistry, to immobilize molecular species for assessing specific interactions, or to enable enhanced imaging conditions. 

Different layered substances on solids Self-assembly structures at interfaces Solid surfaces Langmuir-Blodgett films Thin-film technology... 

Farias and co-workers [30] reported the synthesis of thin hybrid films made of PANI and a ceramic used in the technological industry, titanium dioxide, which were prepared via the layer-by-layer self-assembly technique. Aiming to improve the dispersion of the ceramic in the polymer matrix, the commercial surfactant, cetyltrimethylammonium bromide (CTAB), was used during the formation of the... 

Adhesion Promoters and Inter- cial Thin Films Besides the above-mentioned inorganic conversion coatings, thin films can act as corrosion-resistant interfacial layers. Their thicknesses normally range from the length of a self-assembling molecule (approximately 2 nm) to about 100 nm. Various surface technologies have been developed so far and could be partly introduced into technical processes. 

In 2007, a team led by Professor E. Thomas of Massachusetts Institute of Technology (MIT) developed a smart gel based on the cephalopod s skin structure. The team used a self-assembling block copolymer thin film made from layers of polystyrene and poly-2-vinyl-pyridine. The thickness of the layers controls the refractive indices and thus the color of the reflected light. The poly-2-vinyl-pyridine layer is designed to alter its thickness in response to stimuli such as pH and salt concentration thus changing the gel s color. 

Kwak SY, Kim SH, and Kim SS, Hybrid organic/inorganic reverse osmosis (RO) membrane for bactericidal antifouling. 1. Preparation and characterization of TiOj nanoparticles self-assembled aromatic polyamide thin-film composite (TFC) membrane, Environmental Science and Technology 2001, 35, 2388-2394. 

Buddy Ratner s interests include biomaterials, tissue engineering, polymers, biocompatibility, drug delivery, surface analysis, self-assembly, nanobiotechnology, RF-plasma thin film deposition and biomaterials education. He has participated in the launch of six companies based on technologies from his laboratory, and serves as a consultant for numerous other companies. 

Polycrystalline silicon thin film transistors have also been employed for the detection of DNA hybridization [16]. A mixed self-assembled monolayer of thiolated DNA probes and mercapto-hexanol was immobilized onto the gold gate of an extended gate poly-Si TFT. A shift of the I-V characteristics on the order of 300 mV was obtained upon hybridization of the immobilized probe with a fully complementary strand. The shift is independent of electrode area, so microarrays can be constructed where a known DNA probe is immobilized on each FET. The inherent miniaturization and compatibility with microfabrication technologies make the technique highly promising for the development of low-cost portable devices. 

---