Is there sustained focus to continue research into coatings tech?
Much has been made of the use and development of ‘functional’ coatings over the last 3-5 years, particularly those that deliver applications that are not normally found in the natural world. Coatings with attributes such as self-cleaning, easy-clean, anti-reflective, anti-icing, self-healing and anti-soiling / fouling have been much touted across multiple sectors, driven by new markets and an increase in demand.
However, in many cases the technologies available have not quite matched the claims proffered by their originators. As a result, there is a growing feeling among the end user community (particularly at Industrial and Commercial level) that innovation doesn’t necessarily equal robust solutions.
As a result, one could be forgiven for thinking that research funding would suffer, but according to many industry figures, the outlook is a positive one. Rather than reducing investment, there is likely to be increase – and it’s due to the fact that in the case of many existing functional coatings the principle has been proven.
Institutes the world over are developing new, innovative solutions through the use of formulaic research to answer some of the challenges currently faced by industry. The advancement of surface engineering continues apace, with a myriad of approaches now used to achieve meaningful results. From microphase-separating block copolymers with anti-fouling properties to the development of coatings with self-repair properties, hierarchically structured coatings, structured coatings with barrier effect, bio-based and bio-inspired coatings, there are few areas that are as yet untouched by the leading research bodies.
Yet, as touched upon earlier, the Grail of the surface engineering world is to make coating technology durable. In many cases, once chemical formulae have been tweaked to achieve lasting durability, the original purpose of the coating tends to suffer and as a result its anti-reflective / self-healing etc properties drop off significantly.
However it depends greatly on the nature of the surface itself. In the case of wood, there have been long-standing coatings that demonstrate both durability (weatherability) and elements of easy-clean etc. The current focus in this sector seems to be the predictability of how weather-proof a coating is, and early detection of weather-induced failure of a coating. This also goes for plastic-based coatings, as rapid deterioration is a common issue.
In the case of silica, or glass, the most common issues tend to be focused around hydrophobicity, anti-soiling and self-cleaning. Hydrophobic silica is available commercially, and there are good examples out there, but the successful examples are dependent on its application, and in the main are in situs where the coating isn’t subjected to extreme weather over time for instance.
There are potentially several reasons for this. The use of non-primary silica particles, or pyrogenic silica – an aggregated form of silica – increases viscosity (which is why pyrogenic silica tends to be used in paints), which for certain characteristics such as hydrophobicity is a problem – water tends to stick to surfaces that have higher viscosity. As a result, introducing pyrogenic silica into a solution is likely to increase its viscosity unless the particles have been functionalised (known as ‘fumed’ silica); but this type of silica is extremely limited in terms of its functionalities.
Conversely, the use of colloidal silica, which are primary particles, gets around many of these issues as the viscosity is reduced. The challenge with colloidal silica is that it has limited applicability in solvent borne systems or where water sensitivity exists.
So in the case of silica, what is the best route to take in terms of formulating dynamic coatings, and what are the best applications of it?
In the case of Sharc Matter, and our approach through the use of SMS, we have taken the path of ensuring the foundation of the functionalisation is robust enough; as a result of extensive testing, we are satisfied that we have an extremely stable baseline. This now allows us to offer users a range of different particle sizes, that once functionalised, can be deployed in different ways to create different coating characteristics. Whether anti-icing, easy-clean, anti-soiling, increased durability or super-hydrophobic, we provide the platform for the most appropriate solution which can then be applied according to user needs.
Sharc Matter’s SMS range can be used across a wide range of applications including a hard-coating agent for plastics, Anti-reflective coatings, scratch resistance, Nano-composites and UV/EB curable coatings. For more information please visit: