Materiolab: Cellulose Nanofibrils (CNF)

Objectives:

  • Conduct a systematic exploration of cellulose nanofibrils (CNF) based on a briefing set by project lead (Meri Zirkelbach) and partner (Dr. Thomas Geiger, who’s part of the Cellulose Biohybrids group of Empa Dübendorf)
  • Develop different processing and combination methods, sensory qualities and/or future applications of the material

Project Duration: November 2023

Designed For: ‘Materiolab’ connect project module, HSLU

Role: Student, Master’s in Eco-Social Design

Overview: A material-driven approach was used to explore cellulose nanofibrils (CNF) and its potential as a material. My explorations led me to see the potential of CNF as a material component that can be used to replace problematic materials (e.g. petroleum based-netting and seedling pots).

 
On the first day of the project, the group met with Dr. Thomas Geiger, the Senior Scientist at Empa’s Cellulose & Wood Materials Laboratory. He gave us an overview of what CNF is, some of its properties and how their lab has worked with the material.
 
CNF stands for cellulose nanofibrils. It is also referred to as nano-fibrilated cellulose. CNF can be extracted from cellulose-containing materials such as wood pulp, other plant pulps or agricultural plant waste. At Empa, the cellulose pulp is mixed with water, put through a cutting mill and then through an ultra fine friction grinder. The result is CNF in a white mass which is approximately 8% cellulose and 92% water.
 
 
Properties:
  • typical fibre lengths are less than 1 micrometre
  • widths range from 20-100 nanometres
  • biodegradable (in home compost)
  • high strength and stiffness
  • water storage capacity (hydrophilic)
  • undergoes hornification when dried
  • significant shrinkage when dried (because it’s mostly water)
 
Currently used in:
  • barrier/separation membranes
  • adhesives
  • nanocompositeds
  • polymer reinforcements
  • paper products
  • biomedical scaffolds

After the first few days of open experimentation, we split up into sub-groups based on our areas of interest. Some groups decided on a more free and speculative approach, while others took a targeted and defined approach. Me and another group mate saw the potential of CNF to be used as an alternative to problematic materials. For example, polypropylene, polyamide or polyethylene.

This is one of the experiments that I spent the most time on and shared during the project presentation. I proposed that a CNF-based material could be used to replace polyamide or polypropylene used in netting.

Building on the challenge of plastics particles leaching into the soils, I also thought about the plastic pots commonly used for starting seedlings. Nursery seed pots are usually made out of the plastic resins polyethylene and polypropylene.

 

This was a 2-week project for the master’s programme. It’s called a ‘Connect Project’ because the design brief is provided by an external partner in collaboration with a project lead who works at the university (HSLU). Students are provided the opportunity to propose design concepts to real-world challenges of organisations, institutions, etc.
 
The brief for this Materiolab project was as follows: During the project, students will work with CNF and self-growing material systems. CNF, or “cellulose nanofibre”, is to serve as a form-giving basic structure in its dried form (structured and shaped). The MaterioLab focuses on the systematic exploration of materials on different levels. In doing so, the project focuses on an iterative, design-oriented and speculative approach, emphasizing both application possibilities and perceptual qualities. It builds on the results of past Materiolab projects. On the one hand, the project aims to develop different processing and combination methods and sensory qualities. On the other hand, the aim is to develop future applications, especially speculative prototypes, that integrate self-forming materials.
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