Canada experiences around 24,000 house fires each year, because of factors such as cooking equipment, like ovens, microwaves, and toasters, heating equipment, like furnaces, and electrical equipment, such as plugs, lighting, and cables. Finding a way to prevent this from happening is essential because these fires can cause many deaths and tragedies, so I think using nanocellulose aerogel for this would be extremely effective and could make Canada a safer place for me, you, and everyone.

In this project, this study aims to; Investigate the properties of nanocellulose aerogel, including its thermal insulation, mechanical strength, and fire resistance, Compare its effectiveness against fireproofing materials and chemicals., Identify and address challenges in its application, specifically its spreadability and adhesion to surfaces like walls,  Develop and test methods to enhance its fireproofing capabilities through foam-based application and sprayable formulations using hydrophobic binders, Assess the real-life feasibility of nanocellulose aerogel in fire prevention by analyzing existing research, experimental data, and theoretical modelling, Determine the future significance and potential applications of nanocellulose aerogel in household safety, construction, and industrial fireproofing solutions. By achieving these objectives, this project seeks to demonstrate how nanocellulose aerogel can serve as a sustainable, lightweight, and highly efficient fire-resistant material, potentially reducing fire hazards in residential environments.

What is nanocellulose?

Nanocellulose is a substance created from nanometric (nanometric is the microscopic unit of measurement) natural cellulose fibers. Cellulose is a natural, organic compound that makes the main structural compound of plant cell walls, also being a carbohydrate made up of glucose molecules. Circling back to nanocellulose, it has a low density, is flexible, and chemically inert. Once cellulose is broken down into small fibers ( about 5 to 50 nanometers wide), it becomes nanocellulose. Another really important property is that it's surface can be chemically modified.

What is aerogel?

Aerogel is a solid material with a structure made up of tiny air bubbles, thus making it extremely light and porous. It is when the liquid inside a gel is removed and replaced with air.

Some properties of aerogel are:

• It has very low density.
• It can be made from a variety of chemical compounds.
• It can be hydrophobic, meaning it repels water.
• It can be used as an insulator, filter, catalyst support, gas and energy storage material, electrical conductor, and lastly can be used to remove pollutants from the air.

What is nanocellulose aerogel and it's properties?

Since I've already explained what nanocellulose and aerogel are individually, to put it simply, nanocellulose aerogel is an extremely lightweight aerogel made from nanocellulose fibres, which are really small cellulose strands. With nanocellulose being strong, flexible and lightweight, and aerogel being extremely light, with high surface area, and excellent thermal insulation (heat resistance), combining them creates a biodegradable, strong, and highly thermally resistant material with potential applications in fireproofing.

Key properties and chemical Mechanisms

• Thermal insulation:
  Nanocellulose aerogel has one of the lowest thermal conductivity among solid materials, meaning it significantly reduces heat transfer. This is because their internal structure consists of nanoscale (tiny) pores filled with air. Since air is a poor conductor of heat, it stays trapped inside these pores, preventing heat from spreading. The aerogels structure is similar to traditional silica aerogels, but they are not a fragile or easy to break.
• High porosity and low density:
  Nanocellulose aerogels are more than 90% empty space, making them extremely light-sometimes as light as 0.01 g/em'. This happens because the tiny nanocellulose fibres stick together through strong hydrogen bonds, creating a connected network as the material dries. These bonds are strong yet flexible, allowing the aerogel to maintain its structure even when pressure is applied.
• Mechanical strength and flexibility:

  Despite their low density, nanocellulose aerogels are still very strong due to the many hydrogen bonds holding the nanocellulose fibres together. When pressure is applied, these bonds can break and quickly reform, spreading the force throughout the material without breaking it. This makes nanocellulose aerogels more flexible than traditional silica aerogels, which as I mentioned earlier, are more likely to crack or break.

• Biodegradability and environmental friendliness:

  Unlike synthetic aerogels or plastic-based insulation, nanocellulose aerogels are fully biodegradable. This means they can break down naturally over time. In the environment, special enzymes called cellulases break apart the cellulose fibres, making nanocellulose aerogels a more eco-friendly and sustainable option for fireproofing compared to traditional materials.

Challenges and limitations of the substance?

Nanocellulose aerogel has many beneficial aspects, like its eco-friendliness, sustainability, and being lightweight and non-toxic, however, there are still many challenges and limitations. These include:

• Hydrophilicity (water absorption):
  Nanocellulose aerogels easily absorb water because they have a large surface area and naturally attract moisture. In humid conditions, they can swell or weaken. To prevent this, naturally, we would need to use something water-resistant to counteract water absorption, and so to chemically modify them we can add water-resistant compounds, such as silanes or fluorinated coatings, to make them more durable.
• Brittleness in dry form:
  Even though nanocellulose aerogels are strong, they can become brittle in very dry conditions because their hydrogen bonds lose flexibility. To make them more durable, they can be mixed with polymers or resins, which help improve their mechanical properties.

Why did I choose nanocellulose aerogel rather than something else?

• Toxicity:
  Traditional fireproofing chemicals, like halogenated flame retardants (HFRs), release harmful gases such as hydrogen bromide or hydrogen chloride when burned. These gases can be dangerous to human health and contribute to air pollution. In contrast, nanocellulose aerogels are made only of carbon, oxygen, and hydrogen, so they do not produce toxic fumes when exposed to flames.
• Environmental impact:
  Many synthetic fire retardants do not break down easily and can build up in the environment and living organisms. Nanocellulose aerogels, however, decompose naturally and do not introduce harmful chemicals into ecosystems, making them a more eco-friendly alternative.
  Efficiency in heat resistance:
  Because nanocellulose aerogels have extremely low thermal conductivity, they can withstand temperatures above 400°C without breaking down. This makes them just as effective as silica-based aerogels for fireproofing.

Why Can't Nanocellulose Aerogel Be Applied to Walls Yet?

• Lack of adhesion: Nanocellulose aerogels do not naturally bond with most building materials due to their porous, hydrophilic structure. However, I found that Surface chemistry modifications, such as adding silane coupling agents, can improve adhesion.
• Structural instability: Without a binding agent, nanocellulose aerogels tend to crumble or degrade over time. I found that adding polymers or resins can create a more durable coating.
• Fireproofing limitations: Pure nanocellulose is combustible. To fix this, it must be chemically treated with flame-retardant compounds before being used as a fireproofing material, as nanocellulose aerogel by itself is not yet fireproof.

How is Nanocellulose Aerogel Created?

1. Cellulose Extraction and Nano Fibrillation: Cellulose is taken from sources like wood pulp, agricultural waste, or bacteria. It is then broken down into tiny fibres using mechanical, chemical, or enzymatic methods.

2. Sol-Gel Formation:

• The nanocellulose fibres are mixed with water to form a stable gel.
• Sometimes, special chemicals (cross-linking agents) are added to make the material stronger.

3. Drying Process: There are two ways to do dry it, first, freeze drying, where the gel is frozen, and then the ice is removed through sublimation, leaving behind the aerogel structure. Second, supercritical drying, where the gel is dried using carbon dioxide in a way that keeps its tiny pores together/intact. 

4. Final Modifications: Once its made, we can add special coatings such as silica, boron, or phosphates, to improve fire resistance.

How can I make it fireproof?

 To make nanocellulose aerogel suitable for fireproofing applications, chemical modifications are necessary to enhance its flame resistance. The key challenge lies in altering the molecular structure of nanocellulose without compromising its lightweight and porous nature. Here are a few methods I found: 

1. Using phosphoric acid treatment. Through some research, I found that when phosphoric acid is applied to nanocellulose, it reacts with the hydroxyl groups on the cellulose molecules which are phosphate esters (organic compounds formed as a result of alcohol and acid).  These phosphate groups promote the formation of a stable char layer when exposed to heat, which prevents further combustion.

2. Boron compounds, such as boric acid or borax are commonly used to enhance fire resistance in cellulose-based materials. I found that when applied to nanocellulose aerogel, boron helps stabilize it at high temperatures by forming a protective layer That prevents it from burning easily

3. Silica nanoparticles can be added to nanocellulose aerogels to improve their fire resistance. Since silica is an inorganic material, it does not burn and has a very high melting point (around 1700°C), making the aerogel more heat-resistant.

How these treatments alter the chemistry of nanocellulose?

When phosphoric acid, boron compounds, or silica nanoparticles interact with the hydroxyl groups in nanocellulose, they either form strong chemical bonds (cross-linking) or create a protective layer that shields the material from heat.

These treatments stop cellulose from breaking down due to high temperatures (a process called pyrolysis), which is what causes most organic materials to catch fire.

How Can I Modify Nanocellulose Aerogel to be Spread on Walls and Last?

Some challenges in spreading nanocellulose aerogel on walls are the porous and brittle nature, Lack of adhesion to surfaces, and hydrophilicity (water sensitivity). Here are some ways I found can overcome these issues while still keeping it fireproof.

1. If I want to improve its flexibility, I would need a flexible polymer. Mixing nanocellulose aerogel with a flexible polymer, like polyvinyl alcohol can improve its mechanical properties. This allows the aerogel to retain its shape without crumbling.

2. When I was thinking of ways to make it easier to spread, one of the first things I thought of was using it as a spray. To do this, it can be mixed into a liquid with water-resistant binders like polyurethane.

3. Another idea that came to mind is a foam-based application method, like those foam sprays used inside walls. This can be done by adding surfactants or stabilizers, depending on there compatibility with nanocellulose, we could use sodium Dodecyl sulfate. Once it's applied, it expands and becomes solid into a proper cover layer, with an easy way of spreading it.

After some consideration, I think that the best method for preventing household fires would be to use the foam-based application on the insides of the walls, to prevent internal fires from incase of an electrical fire from inside the walls. I would also use the spray on coating for stuff like furniture, and even after adding the foam-based application on the outside of the wall as well, I would use the spray over it, as the foam will still char, so to prevent that from happening as well, I would use the spray over it.

Feasibility and Research-Based Proof

Here's my first scenario. Hypothetically, if I were to have phosphoric acid-treated nanocellulose aerogel (the foam), try to light it on fire with a burner flame at 1200*c, for 5 minutes the phosphoric acid would act as a dehydrating agent, removing hydroxyl groups and creating a char layer as I mentioned before.

Generally, nanocellulose aerogels with this treatment would withstand temperatures up to 800 to 1000c, but if I were to burn it at 1200c, the phosphorus should enhance its ability to resist burning completely/ complete combustion.

Additionally, mass loss at 1 minute is unlikely to set on fire, if I were to measure the exact mass loss which is already low, if I were to extend that only by 5, it could cause extreme damage, but still hold its ground.

There is also a possibility that it failed and the long exposure at this temperature would eventually degrade. So based on that information, I can say that if I were to use it as a protective layer on a material, it should protect it from lighting on fire for a good amount of time.

Based on what I've mentioned so far, I can say that the sprayable (hydrophobic) aerogel prevents something from catching on fire, and when applied to drywall panels, it should prevent fire from spreading.

So, imagine this: there is a lem thick layer of foam based nanocellulose aerogel applied to walls (and inside the walls) and ceilings, with a thin sprayable coating on furniture, curtains, and wooden surfaces.

Let's say a candle accidentally fell on a coated wooden table, the flame should fail to ignite the surface because of the hydrophobic and flame resistant properties, and would self extinguish.

Next, kitchen fires are a pretty common mistake, so let's say oil ignites on a coated wall, the high-temperature flames from the burning oil would fail to transfer heat, though it would still char, it would not ignite

Lastly, let's say there was an electrical fire in a room with coated surfaces. If a short circuit sparks a fire, the spray-coated furniture and wall insulation would not catch on fire. The aerogel would stop it before it even spreads.

So, based on these real-life scenarios, and, and hypothetical fire tests, using nanocellulose aerogel as protection should work in preventing household fires.

Future applications

It could also be used on buildings, around fences for houses and gardens, and even the factories themselves that make it. What if nanocellulose aerogel were to be incorporated into the fabric to create lightweight, non-toxic flame resistant clothing for all workers in dangerous areas. I also think it could have potential use on aircraft and electric vehicle batteries to protect from overheating and fire protection, preventing internal fires to continue spreading by putting them out as they start, while maybe adding heat or fire detectors so we know if it was gonna ignite.

To make this realistic if we were to actually try to make it around the world, here's my estimate cost, let's start with how much it would cost to make it:

1. Raw Materials (Wood Pulp/Cellulose Source): 

- Wood pulp is a cheap and common source of cellulose, which would cost $0.50-$1.00 per kg.The raw material cost is about $0.75 per kg of nanocellulose

2. Processing Costs (Nanofibrillation, Dispersion, and Gelation):

- Nanofibrillation (Breaking cellulose into nanofibers): Requires energy and equipment like homogenizers or chemical treatments, costing $5-$10 per kg.

- Gelation and Solvent Exchange: Turning nanocellulose into a gel and replacing water with ethanol or acetone adds another $2-$5 per kg.

3. Drying Process (Aerogel Formation)

- Freeze-Drying or Supercritical Drying: A high energy step that

costs $5-$10 per kg.

4. Fireproofing Modifications:

- Adding flame-retardant chemicals (e.g., phosphoric acid,

siloxane, polyurethane) costs $5-$10 per kg.

5. Overhead and Scale-Up Costs:

- Factory overhead, labor, and maintenance: Adds $2-$5 per kg.

- Economies of Scale: Larger production reduces costs, but initial

investments and regulations may keep costs high at first.

These estimates give a general idea of the costs and feasibility of using fireproofed nanocellulose aerogels in construction, however, it is just my estimate, it might not be accurate:

Raw materials	~$0.75
Nano Fibrillation and Gelation	~$7.50
Solvent Exchange	~$3.50
Drying Process,	~$7.50
Fireproofing Modifications	~$7.50
Overhead and Scale-Up Costs,	~$3.50
Total Cost Per kg	~$30.25

 

In conclusion, nanocellulose aerogel could be a game-changer for preventing household fires. It’s super lightweight, has great insulation, and doesn’t burn easily, making it a strong alternative to traditional fireproofing materials. There are still some challenges, like figuring out how to apply it properly and making it affordable for large scale use, but research shows that it has a lot of potential. With more development, this could be a big step toward making homes safer from fires in a way that’s also better for the environment.

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Nanocellulose Embedded Polymer Composite Foams for Flame Retardancy