What is Cellulose fibrils and Exilva microfibrillated cellulose?
Ole Martin Kristiansen | March 20, 2018
Never heard of Cellulose Fibrils, like microfibrillated cellulose (often referred to as nanocellulose)? Don't worry, I will guide you through the things you need to know. It is a completely new additive made from natural raw materials, designed to provide yield stress, shear thinning, stability and barrier improvements. It is the natural alternative to outperform current oil-based technologies. I will during this article give you a quick overview of what cellulose fibrils, using the example of Exilva microfibrillated cellulose, is and how it can benefit you.
Functionalities from the characteristics of Exilva microfibrillated cellulose
It is when using the Exilva microfibrillated cellulose (MFC) in products like paint & coating, adhesives, agricultural chemicals etc. the really interesting discoveries start. The fibrils 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 providing a very effective anti-sag and anti-dripping additive. It is also well known for its high yield stress, providing ability to reduce settling and sedimentation. The very high viscosity at rest can also reduce syneresis. Through its non-soluble three-dimensional network, it also has shown potential as a stabilizer, especially at stabilizing emulsions (water-in-oil or oil-in-water). By its physical presence, it has shown its potential as a potent stabilizer of high solid systems, systems where settling is typically an issue.
Exilva MFC also shows high robustness to pH, temperature and shear. This in turn give you opportunities to test and use the product acidic or alkaline formulations, or in processes where high temperatures and shear forces are needed.
The Exilva microfibrillated cellulose has a massive surface area. Setting this in context,1 gram of the fibrils can cover the floor of a big family house(about 200 m2). The massive surface area gives a large number of available OH (hydroxyl) groups which are hydrophilic by nature, and rapidly grasp onto waterin its proximity. This is shown by a very high water retention value (ability to hold water). It can oftencarry water quantitiesof more than 40 times its own weight.
To even better understand the effect of these functionalities, take a closer look into what the Exilva microfibrillated cellulose is all about in this 3D-video:
Exilva microfibrillated cellulose seen through a scanning electron microscope
History and background
Cellulose fibrils, like microfibrillated cellulose 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 has the material become commercially available through Borregaard in Norway.
A 3D animated version of the cellulose fibrils network.
Biofuels Digest wrote a 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, Cellulose fibrils, like microfibrillated cellulose, should be on the agenda as an equally performing option alongside the oil-based products.
Editor's note: This post was originally published in April 2016. We've revamped and updated it for accuracy and comprehensiveness.
Ole Martin Kristiansen
Ole Martin is the Marketing Manager of Exilva in Borregaard. He holds a bachelor's degree in Media Management and has been with the company since 2017.