Never heard of MicroFibrillated Cellulose (MFC)? Don't worry, I will guide you through the things you need to know. MFC is a completely new performance additive made from natural raw materials, designed to outperform current oil-based technologies. I will during this article give you a quick overview of what MFC is, its characteristics and functionalities, and what you can do with it.
History and background
MFC is a fairly new concept, at least in commercial terms. The concept was developed at the laboratory of ITT Rayonnier, by Albin Turbak and his team, in the late 1970´s and early 1980´s. The reasoning behind it was to provide a new quality of cellulose with a much higher surface area, by passing wood pulp through a milk homogenizer, in order to entangle the network of fibers into much smaller fibrils. The technology developed by Turbak et al. was not pre-commercially pursued before smaller activities started in Japan in the 1990s. During the 2000s, several companies initiated research activity within the field, and only recently is the material becoming commercially available through Borregaard in Norway.
Biofuels Digest wrote an good article on the subject back in 2014, using the phrase, “It might be the oddest, most interesting product you can make out of a forest, and displace products made from petrochemicals”. This new environmentally friendly performance enhancer can, in a more sustainable way, do the same job as the currently available oil-based technologies. In the current scenery of climatic change and increased incentives to improve CO2 footprints, MFC should be on the agenda as an equally performing option alongside the oil-based products. MFC is a new innovation, from bio refineries and research institutes, where cellulose fibers are fibrillated (meaning that the mother fiber is split into a higher number of thinner fibers). This creates an increased surface area giving the novel fibril product new characteristics. MFC is typically sourced from softwood and hardwood sources, as well as vegetable sources. Thus it is one of the most sustainable alternatives on the market.
What are these new characteristics of MFC? Well, the new product’s main secret is the massive surface area. Setting this in context, 1 gram of MFC can cover the floor of a big family house (about 200 m2). This, of course, depends greatly on the process the product held in your hand has gone through, and the ability of the producer to fibrillate (delaminate) the fibers. The massive surface area gives a large number of available OH (hydroxyl) groups which are hydrophilic by nature, and rapidly grasp onto water in its proximity. This is shown by a very high water retention value (ability to hold water). It can often carry water quantities of more than 40 times its own weight.
Its non-soluble nature gives highly pH tolerant and temperature stable characteristics. This means that it can open opportunities even in environments that are relatively hostile
Picture: MFC seen through a scanning electron microscope
Still interested? It is in the application of the MFC the really interesting discoveries start. MFC is in most instances a hydrophilic material, and is thus best suited in water based/water borne systems. It can act as an advanced rheology modifier giving very interesting spraying characteristics and an unusually high viscosity at rest. It is famous for its shear thinning and non-Newtonian behavior. It also has shown potential as a stabilizer, especially at stabilizing emulsions (water-in-oil or oil-in-water). The multifunctionality of MFC also enables it to partly take out stabilizing additives/ingredients like surfactants. In addition, MFC has shown potential as a strengthening additive (showing higher strength than Kevlar), barrier performance and filtering performance. Due to these functionalities, there has been an increasing interest in the use of MFC in applications like coatings, adhesives, agchem, electronics, cosmetics and many others. It's a question of achieving better results, with a new and natural innovation.