Printed electronics suit well for the current mega trends, like internet of things and growing interest in monitoring your own health. The products produced by printed electronics vary from displays and sensors to energy storage and flexible conductors. For example, small sensors can be printed on food packaging to follow the quality of food as well as warn the consumer when the product is out of date. For such reasons, the interest for developing materials for printed electronics is growing. How can cellulose fibrils and other cellulose based materials be used in such applications?
Is microfibrillated cellulose (MFC) the same as nanocellulose? What is the difference between micro- and nanofibrillated cellulose? What about cellulose nanocrystals and cellulose fibrils? Starting to read about MFC (or nanocellulose) might be confusing since the terms used for nano- and micro-sized cellulosic materials are versatile. Moreover, they are not totally established, so the same material can have different names or the same terms can be used for very different kind of materials. In this post, I will introduce the most common terms and distinguish synonyms from different materials.
Dust originating from abrasion of dry materials can cause a danger to the health and environment. One of the industries that is paying a lot of attention to dust control is the seed treatment industry. Seed treatments are an essential part of today’s agriculture and it means applying the crop protections products, like insecticides and fungicides, directly on the seeds before planting. This is regarded as an effective way to apply the crop protection products and can reduce the needed amount of the products in total. However, the applied substances can start wearing off from the seeds when they are transported and handled which can cause unhealthy dust.
Typically, when using polymeric rheology modifiers, the viscosity of a formulation decreases with increasing temperature and the polymers can even degrade at higher temperatures. This can cause problems for the manufacturer or user, like instability of the formulation or difficulties in application. Cellulose fibrils and cellulose in general are stable against temperatures up to 200-300 °C, which makes them a good choice when a temperature stable viscosity modifier is needed. Earlier, we have described how you can achieve a stable viscosity in your formulation with cellulose fibrils in the temperature range of 20-90 °C. This time I would like to discuss what happens when we go over 100 °C, either in wet or dry state.
Cellulose fibrils has shown great potential as an oxygen barrier in packaging. This has led to numerous research projects trying to utilize the potential in practice. But how does the fibrils actually create the barrier towards oxygen?
Water holding capacity, or high water retention value, is often mentioned as a key property of cellulose fibrils. When it is dispersed into water, the fibrils trap water between them and do not release it easily. As a consequence, even rather low concentration of MFC in water has gel-like appearance since the water is not able to flow freely. What is behind this? Let’s try to find out.
Plastic microparticles found in the environment have gotten a lot of attention lately. Many of the plastics are very durable and do not degrade in a reasonable time in the nature, although today there are also biodegradable plastics available. Small pieces of plastic can be found almost everywhere on the Earth and it is not fully understood what kind of consequences that could have for the human beings and environment. Therefore, replacing non-biodegradable plastics with biodegradable materials in packaging, clothes and cosmetics has high focus right now. Cellulose fibrils come from wood or other natural resources; are they biodegradable? Can they replace non-biodegradable plastic and reduce the amount of microplastics in the environment?
Governments around the world are pushing industries to reduce their volatile organic compound (VOC) emissions. VOCs include very different type of chemicals but they may be dangerous to human health and therefore there is a common desire to reduce the use of them. Health effects vary from eye, nose and throat irritation to causing cancer.
Microfibrillated cellulose (MFC) differs from many rheology modifiers in that aspect that it can be used in high salinity formulations. The rheology effect comes from entangled fibers and salts do not influence this network as it does when the rheology effect is based on ionic interactions. However, the viscosity and other rheological properties vary slightly as a function of salt concentration. Let’s take a closer look at the reasons behind this.
Three dimensional (3D) printing and tissue engineering are two fields that are currently developing rapidly and are both exciting technologies on their own. What if you combine them? That creates a new manufacturing process, bioprinting. It is a promising technology that might be the key to the on-demand tissue engineering. Microfibrillated cellulose (MFC) or nanocellulosic materials generally have an important role in the development.