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The modern microsphere industry is helping to improve the ancient technology of preserving wine in bottles. By using AkzoNobel’s branded polymer microsphere Expancel, synthetic corks are able to make a seal that in many ways is superior to natural cork.

As the Expancel website boasts, “Synthetic cork can be a good solution in many applications. In theory, synthetic cork should avoid many of the inconsistencies associated with natural cork. But in practice, it’s not that simple. The foaming process is often the cause when there are issues. The key to the real-world performance of synthetic cork is the foaming process. Expancel [microspheres] in the mix ensures highly controlled foaming, giving very even and consistent results.”

Dominique Tourniex, CEO at Diam, a global leader in cork manufacturing, said, “We are purchasing little, tiny microspheres which expand during the process of mouldng the cork and so improve the performance of the closure.”

Better still, the microspheres help form a watertight seal that does not shrink or absorb moisture. It removes the chances of ‘cork taint’ in the wine, is European regulation 10/2011 compliant, and has recently been US FDA approved.

You can watch the presentation on how microspheres help improve cork manufacturing on YouTube here.

Given that, according to the Wall Street Journal, global wine consumption in 2014 was set at 38.4 billion bottles a year, then there is clearly a good market for cork manufacturers. While traditional wine markets in the US and Europe are currently stable, it is the booming demand for wine in the Far East that has packaging manufacturers whetting their lips. While the market is comparitively small at present, that is expected to change in the coming decade. For example, China alone, “saw a 69% growth in wine consumption from 2009 to 2013 and is forecast to grow by almost 25% from 2014 to 2018.”

With so many thirsty mouths and a desire for western lifestyles, the microsphere market could easily grow as wine consumption also takes off. With demand already growing through pressure from other chemical industry applications, raw material traders are beginning to wonder, “how high can microsphere prices reach, if new suppliers are slow to enter the market?”

Photo credit: AkzoNobel

Medical implants are often coated in polymer films that help the body adhere to the implant. These polymer films are usually created via a process called chemical vapor deposition (CVD) polymerization, whereby the initial compounds are evaporated, activated at high temperature, and deposited onto surfaces, where they polymerize. However, until recently no one has been able to develop a suitable CVD coating for degradable implants, such as surgical sutres, tissue-culturing scaffolds, and stents.

But now an international team, that includes researchers from Karlsruhe Institute of Technology, Germany, the University of Michigan, USA, and Northwestern Polytechnical University, China, is reporting that they have made a breakthrough, as they claim to have synthesized a CVD polymer with a degradable backbone. Publishing their results in the journal Angewandte Chemie, they explain the challenge and opportunity as follows;

“Polymers prepared by chemical vapor deposition (CVD) polymerization have found broad acceptance in research and industrial applications. However, their intrinsic lack of degradability has limited wider applicability in many areas, such as biomedical devices or regenerative medicine,” adding that, “These coatings address an unmet need in the biomedical polymer field, as they provide access to a wide range of reactive polymer coatings that combine interfacial multifunctionality with degradability.” By using a different type of bond between the polymers, the researchers have been able to solve this problem.

As the online scientific journal Phys.org explains, “The team applied co-polymerization of two special monomer types: The para-cyclophanes usually used for this method were combined with cyclic ketene acetals. While classical polymers on the basis of para-cyclophanes are linked by carbon-carbon bonds exclusively, ketene acetal is repositioned during polymerization, such that ester bonds (e.g. bonds between carbon and oxygen atoms) are formed in the polymer backbone. Ester bonds can be cleaved in aqueous medium.”

Better still, the rate of degradation is also adjustable, because, as Lahann explains, “The degradation rate depends on the ratio of both monomer types and on the side groups of the monomers. Polar side groups make the polymer film less water-repellent and accelerate degradation, as water can enter more easily. In this way, the degradation rate can be adapted to application.”

The picture at the top of the page shows a microscopic fluorescence image of the biodegradable coating with structures printed onto it for test purposes.

Importantly, the team have already proved that the degraded products are non-toxic, and the medical world is beginning to take note. But now, plastic coating specialists and polymer film traders are also considering the importance of the development, as the process may well have applications beyond biodegradable medical equipment.

As Professor Joerg Lahann, Co-Director of the Institute of Functional Interfaces of Karlsruhe Institute of Technology (KIT), explains, “Our new degradable polymer films might be applied for functionalization and coating of surfaces in biosciences, medicine, or food packaging.” Furthermore, because the process allows for the production of polymer films with “functional groups” as ‘anchor sites’ for fluorescent dyes, biomolecules, or any manner of active substances, then many other applications may be possible.

If the process can be scaled up to an industrial scale at an economic rate, then where would you apply a non-toxic, biodegradable, reactive polymer coating?

Photo credit: KIT

While material science and the chemical industry are finding new markets with new products, such as graphene, biodegradable polymers and bio-plastics, currently it is an older form of technology which is seeing some of the best market growth.

Microspheres are being seen as one of the chemical industry’s new wonder-products, praised for their seemingly simple design, yet great versatility. Perhaps best of all is how microspheres can be adapted to suit all manner of chemical engineering challenges.

For example, the company APM, one of the world’s leading microsphere producers, has this to say, “Our aim is to deliver value to our customers’ businesses by providing functional filler systems and solutions. Since customers have different needs, we can provide tailor-made products to meet their needs.”

Many new uses are being found at the Savannah River National Laboratory, in South Carolina, where Ceramics magazine reports on the uses of porous-wall, hollow glass microspheres (or PWHGM’s for short). These high-spec microspheres were developed, “primarily for nuclear-related purposes, including storage of radioactive isotopes of hydrogen and separations. However, the reach of PWHGMs extends much further—microspheres have potential uses in energy technologies (e.g., hydrogen storage for hydrogen vehicles, improvements in lead–acid batteries, and new concepts in lithium-ion batteries), environmental remediation (e.g., global warming studies and CO2 sequestering), textiles, medicine, and security.”

Chris Rosenbusch, Marketing Manager for microsphere manufacturer Expancel Inc. (part of the AkzoNobel group) is also keen to talk about the many qualities that microspheres can provide, noting that, “Most users focus on one or two attributes of the spheres, but in the composites industry, manufacturers are taking advantage of six or seven attributes.”

With so many applications in so many different fields, it is little wonder that interest among raw material suppliers and in the manufacturing industry is growing. This is a point supported by Gary Gladysz, VP of technology at Trelleborg Emerson & Cuming, a global leader in the product, who states that the most amazing thing is that, “The microsphere can be tailored to achieve multiple objectives in one part.”

With their importance increasing in a number of growing markets (the battery industry, pharmaceuticals, textiles, energy, security measures, speciality chemicals, construction products etc.) then it is clear to see why so many predict that in the future microspheres will get bigger. AkzoNobel calls them, “The world’s favourite secret ingredient,” but with sales expanding as microspheres find their way into more and more products, how long will it be before the secret is out?

Photo credit: Kulin corp.