Cellulose

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Biodegradable 232 Bioplastic 78 Plant-based 168 Recyclable 119 Agar agar 22 Cellulose 10

Cellulose

Photos: Müge Yildiz

Celluloid: Making Analogue Film Base

The film known as a motion picture was started to be produced by Kodak in 1889 as cellulose nitrate. This film, which contained heavy chemicals, caused many workers to get sick and die during its production, nitrate was also flammable, the film self-destructed over time and caused many buildings to burn due to improper storage conditions. In the 1950s, cellulose acetate and polyester films began to be produced. Although the chemicals had changed, plastics were produced from cellulose. This analogue film was not only plastic but also has a gelatin component, made of animal collagen, and bones. The study investigated bio-based cellulose as a sustainable and renewable material and the potentiality of creating analogue films and finding ways to make films that are less harmful to the environment.

This study looks for a cellulose-film base with various stages so that the "strength," "flexibility," "durability," and "colour/emulsion absorption" of the materials can be investigated. The project's objectives were to produce a base for CNF (cellulose nanofibre) films, combine and test the film base with agar agar, and generate images using natural dyes, cyanotype chemicals (potassium ferricyanide + ferric ammonium citrate), and plant-based solutions (vitamin C + baking soda). Three layers make up the fundamental parts of an analogue film. In this experiment, agar agar (seaweed) mixes were employed to generate the analogue film instead of gelatin, which is made from animal bones and collagen, or a UV-protective base, chemical component of the film, a silver nitrate emulsion.

In the first effort, different phases of the cellulose-based film-making process involved combining CNF with agar agar. These two materials were made by layering them one after the other, mixing them, and then creating separate batches and combining them afterwards. They were all dried at a temperature of fifty degrees Celsius. There were bubble issues to construct a clean film base for three of them. CNF calls for a high number of mix hours. The CNF film foundation is typically fragile despite having flat surfaces. In agar agar testing, the film foundation in two distinct layers yielded the best results.

Ultimately, the delicate structure of CNF was enhanced using MFC (microfibrillated cellulose) in contrast to these studies. In summary, the film base obtained a stronger material by mixing CNF and MFC as opposed to utilizing CNF alone. Although CNF has flat surfaces, it is brittle by nature, thus finding other ways to make it more durable is necessary. But bubbles on the film base are still a possible problem no matter which method is used. However, after some experimenting, CNF appears to have promising possibilities for this celluloid film project, which gives hope for its prospective uses in the future.

Numerous non-toxic and less harmful substitutes were tested for the last step, which involves creating images for the film base, photography, and print applications. The use of plant-based photographic emulsions (phytograms and anthotypes) and cyanotype, sometimes referred to as Sun/Solar or Blue prints, one of the first photographic printing processes, were selected.

Anthotype simply provides a simple application for plant extract. The product's colour was achieved by utilizing the plant extract. CNF film bases that had been combined with agar agar powder were treated with this liquid. Unfortunately, the film base materials' improper absorption of the solution resulted in the rapid disappearance of the images. It demonstrates the requirement for a material-based formula in the process. The alternative method involves creating images with a plant-based solution and is referred to as phytogram. This process involves creating a simple solution using 500 ml of water that contains citric acid, baking soda, or vitamin C in a 1:1 ratio. After soaking in this solution for a while, the plants were placed straight onto the film foundation. The images faded rapidly even though the plants left their mark on the film, and this approach was only effective with turmeric anthotype film bases.

The final formula employed in this project was cyanotype, which is composed of less toxic or harmful chemicals, as well as ferric ammonium citrate and potassium ferricyanide. Potassium ferricyanide, despite having cyanide in it, this chemical is not very hazardous. The cyanide groups are unable to function as a toxin because they are attached to the iron atom. Strong acid is not utilised in the cyanotype process, but if potassium ferricyanide is placed in a solution of strong acid, the cyanide groups may be liberated as hydrogen cyanide gas.1 In the darkroom, a number of cellulose materials were treated with cyanotype chemicals and allowed to absorb chemical mixtures. The film bases that had absorbed the solution were directly covered with the picture patterns, which were then rinsed with chemicals and allowed to air dry after being exposed to the sun for five to fifteen minutes. In order to treat this film foundation as a real 16mm film and attempt to work with it for additional experiments, the words "This is a film from Nanofibre Cellulose" were scratched or inscribed on the film. The perforation holes on the film base were carved to resemble 16mm film. All things considered, these materials absorbed the cyanotype chemicals successfully, and the procedure only took five minutes when exposed to sunshine. The chemicals were subsequently removed by washing, but the colour didn't change.

The results of the research indicate that there is a possibility that CNF material can be utilised as a replacement to CDA (cellulose diacetate) when combined with another substrate, such MFC. The bonding with MFC in particular provides a surface that is less brittle and stronger. The techniques used to create images can be tested with chemicals like silver nitrate or halide, but it is more important to look into non-toxic, plant-based solutions. In this way, the project serves as an introduction to the creation of biobased, biodegradable, and sustainable analogue film materials.

Information submitted by the maker and edited by the Future Materials Bank.

Ingredients

Cellulose nanofibre (CNF), CMF, agar agar, potassium ferricyanide, ferric ammonium citrate

Credits

Chemarts (Aalto University)