Cellulose nanofibers - Case Studies
Analytical Instruments Are Essential for Utilizing CNFs
CNFs are generally produced from pulp by a top-down approach, using a variety of methods, such as TEMPO oxidation, grinding, aqueous counter collision, and acidic or enzymatic hydrolysis methods.
At the same time, CNFs (NFBCs) can also be produced from sugars or other small biomass molecules based on a bottom-up approach, by cultivating the fibers in an aerated culture with a suitable dispersing agent added to cellulose-producing bacteria (acetic acid bacteria). Due to the variety of methods available for producing CNFs, the CNFs produced by each method can have a wide range of structural and compositional characteristics.
Currently, there are active efforts around the world to develop CNF applications that take advantage of the specific properties and structural characteristics of the different CNFS. However, in order for CNFs to be used on a commercial scale, as a raw material with a given quality level, it is extremely important to measure a wide variety of characteristics, such as dispersibility, shape, fiber length, crystallization level, heat resistance, molecular composition, cohesiveness, concentration of solids, and mechanical properties, so that standards can be established.
With current efforts to establish standards being spearheaded around the world and in Japan, such as at the National Institute of Advanced Industrial Science and Technology and at other relevant companies, there is a need for measuring devices that are not only accurate, but also quick and easy to operate. In Japan, CNFs with unique characteristics are being created in respective regions of the country, with academic institutions engaged in basic research and companies developing commercial applications in each of those regions. Consequently, weanticipate the use of CNFs in a wide range of fields.
Associate Professor, Laboratory of Polymer Chemistry Division of Applied Chemistry, Graduate School of Engineering, Hokkaido University
More data of CNFs from various aspects under various conditions should be accumulated to further expand the practical productions and applications of CNFs.
Plants produce cellulose nanofibers (CNFs) ~3 nm and several μm in width and length, respectively, in their cell walls from CO2 and water by photosynthesis. The CO2-accumuated CNFs behave like reinforcing steels and cause the high strengths of plant bodies against gravity or weather. In this century, fundamental and application researches related to CNFs have been carried out extensively worldwide, because CNFs are bio-based and promising nanomaterials produced from abundant and renewable plant biomass recourses.
Numerous scientific publications and patents have been reported up to date, and these numbers are still increasing. Some CNF films have unique mechanical, optical, oxygen-barrier, electronic, and thermal properties, which are required for high-tech materials and devices.
When CNFs are mixed with plastics under suitable conditions, extremely strong but light nanocomposite materials can be obtained, which are applicable to automobile bodies and housing materials for building construction. However, more fundamental and theoretical data of CNFs from various aspects under various conditions should be accumulated to further expand the practical productions and applications of CNFs. Moreover, establishment of reliable analytical methods/techniques for CNFs with various nano-sized orphologies
is required for scientific interpretation/improvement of various CNF-related experimental data.
Prof. Akira Isogai
Bionanomaterials & Cellulose Science
Department of Biomaterial Sciences
The University of Tokyo
Borregaard produces advanced and environmentally friendly biochemicals that replace oil-based products. Borregaard is also a leading producer of cellulose fibrils, including Exilva Cellulose Nano Fibrils, and have launched the world’s first commercial plant for producing this product.
Industrialization and practical use of Exilva
Exilva microfibrillated cellulose is giving functionalities relating to rheology, stability and film forming. It can build yield stress, combined with a sharp and defined yield point. This is providing you with a very efficient additive for stability. Exilva is used for stabilizing e.g. coatings, adhesives, agricultural chemicals. The shear thinning behaviour makes it very suitable for controlling spray behaviour and stability in chemical formulations.
Consequently, Exilva can give benefits like anti-settling, anti-sag, anti-sedimentation, improved spraying, and film forming.
Outlook for the future of CNF
Some sources are expecting the market for cellulose fibrils to surpass USD 1 billion by 2024. The interest in this product is very high from the industry and the sustainability profile this product delivers is fitting well with the increased demand for bio-based additives.
Expectation for analysis and measurement
We encourage further development of measurement methods to determine individual fibril size and distribution as well as aspect ratio of dispersed CNF. Other properties such as morphology and surface charge and potential is also of high interest. Continuous measurement of coalescence behavior would be very helpful for understanding and development of applications for CNF.
Furthermore, it will be highly beneficial to relate advanced and time consuming measurements to less complex in-line or lab measurements to facilitate faster CNF market growth.
Dr. Hans Henrik Øvrebø
Chief Technology Officer