All sprayed at once: Ultrathin coatings made through simultaneous spraying of interacting substances

Nov 24, 2010

(PhysOrg.com) -- Coatings functionalize surfaces or protect them from processes such as corrosion, abrasion, and weathering, and may provide an aesthetic appearance—automotive coatings and non-stick frying pans are good examples. Contact lenses, implants, LEDs, or photovoltaic cells require extremely thin coatings.

In the journal , the teams led by Gero Decher at the Institut Charles Sadron in Strasbourg (France) have now introduced a new process for the production of ultrathin coatings that is especially simple, versatile, and suitable for large-scale processes.

A simple yet powerful method for the assembly of nanoscale films is the already well-known layer-by-layer technique. Two mutually interacting species, for example positively and negatively charged polymers, are consecutively adsorbed from solution, forming hybrid thin films through a self-organization process. One major improvement to this method was introduced with the technique of spray-assisted deposition, in which atomized mists of solutions containing each of the two substances are sprayed on a in an alternating fashion. This accelerates the process and facilitates scaling up to industrial levels.

The French–German researchers led by Decher and Pierre Schaaf at the Centre National de la Recherche Scientifique and Jean-Claude Voegel at the Institut National de la Santé et de la Recherche Médicale have now been able to make another substantial improvement to this technique: In “simultaneous spray of interacting species” (SSCIS), the two complementary components are not applied consecutively, but are simultaneously sprayed against a receiving surface. Depending on the process conditions, the partner substances rapidly form a continuous layer. The thickness of the film is controlled by changing the spraying time and can range from a few nanometers to a few micrometers. This results in highly homogenous coatings that can even possess optical quality.

The one-step process is cheap, robust, user-friendly, and unbelievably versatile. In principle, all pairs of substances that interact with each other, such as inorganic ions of opposite charge, are suitable for use with the simultaneous spray process. It is thus possible to produce films of calcium fluoride (for optical components) or deposits of calcium phosphate (for use in biomaterials).

Interestingly, the new technique also works with pairs that do not produce intact layers when the conventional layer-by-layer process is used. Thus the presented results open up a wealth of new possibilities to produce surfaces with tailored specific functionalities, for example for catalysis, to make implants more biocompatible or for tissue engineering.

Explore further: Nanoparticle technology triples the production of biogas

More information: Gero Decher, Spray-On Organic/Inorganic Films: A General Method for the Formation of Ultrathin Coatings, Angewandte Chemie International Edition, dx.doi.org/10.1002/anie.201002729

Related Stories

Researchers 'design' therapeutic coatings of silver

Jul 05, 2010

(PhysOrg.com) -- Swiss researchers have demonstrated how they can adjust process conditions to influence the properties of novel plasma polymer coatings containing silver nanoparticles. Tailor-made films can ...

DNA layer reduces risk of reserve parts being rejected

Mar 20, 2007

Dutch researchers Jeroen van den Beucken and John Jansen have given body implants a DNA layer. This layer ensures a better attachment, more rapid recovery of the surrounding tissue and less immune responses. ...

New Oxford spin-out to transform surfaces

Sep 07, 2006

The latest spin-out company from the University of Oxford, Oxford Advanced Surfaces Ltd, plans to apply surface science to develop a revolutionary coating for materials like plastics and Teflon.

Recommended for you

Nanoparticle technology triples the production of biogas

Oct 22, 2014

Researchers of the Catalan Institute of Nanoscience and Nanotechnology (ICN2), a Severo Ochoa Centre of Excellence, and the Universitat Autònoma de Barcelona (UAB) have developed the new BiogàsPlus, a technology which allows ...

Research unlocks potential of super-compound

Oct 22, 2014

Researchers at The University of Western Australia's have discovered that nano-sized fragments of graphene - sheets of pure carbon - can speed up the rate of chemical reactions.

User comments : 0