Making aerogel
TLDRThe video script details an ambitious DIY project to create aerogel, one of the lightest materials known, primarily from silica. The process is intricate, involving making an alcohol-based gel and drying it carefully to avoid cracking. The creator sourced a dangerous chemical, TMOS, and mixed it with methanol and diluted ammonia under a fume hood. After molding and several soaks in methanol, the gel was prepared for supercritical drying with CO2. The first attempt using a heat gun resulted in cracked aerogel, but a second attempt using a Sous Vide cooker proved more successful, yielding an uncracked, albeit slightly yellow, aerogel. The video also touches on the challenges of such projects, the creator's use of a second channel for more casual science content, and a sponsorship by Raycon for wireless earbuds.
Takeaways
- 🌌 The process of making aerogel is complex and time-consuming, involving multiple stages from creating a gel to supercritical drying.
- 🛠️ The speaker used a specialized supercritical dryer and a Sous Vide cooker for temperature control, demonstrating the use of unconventional tools in scientific experiments.
- 💡 Silica aerogel is extremely light due to its composition of less than 1% silica and over 99% air, making it an excellent thermal insulator.
- ⚙️ The supercritical drying process replaces the liquid within the aerogel with carbon dioxide (CO2), which is then heated until it reaches a supercritical state, avoiding capillary action and structural collapse.
- 🔍 The speaker encountered issues with cracking when using a heat gun for the supercritical drying step, indicating the sensitivity of the aerogel to temperature variations.
- 🔵 The final aerogel product has a distinct blue haze, which is a characteristic property of aerogel materials.
- 🚫 Safety is paramount when handling chemicals like tetramethyl orthosilicate (TMOS), which is dangerous and can cause permanent blindness if not handled properly.
- 🧪 The initial gel creation involved mixing methanol, dilute ammonia, and TMOS, highlighting the chemical process behind aerogel formation.
- 📏 A plastic cookie cutter and a carefully constructed wax mold were used to create shaped gels, showcasing creativity in the face of material limitations.
- 🔄 The methanol within the gels was exchanged for an equal amount of liquid CO2 in a step-by-step process, emphasizing patience and precision.
- 🎥 The video provides a behind-the-scenes look at the challenges and iterative process of scientific experimentation, including the use of alternative methods and equipment.
Q & A
What is aerogel and why is it considered one of the lightest-known materials?
-Aerogel is a synthetic porous ultralight material derived from a gel, where the liquid component of the gel has been replaced with a gas. It is considered one of the lightest-known materials because it can have extremely low densities, with over 99% of its volume being air, making it extremely light and difficult to perceive when held.
What is the most common type of aerogel and what is it primarily used for?
-The most common type of aerogel is made from silica. It is primarily used as a thermal insulator due to its composition of mostly air trapped in a network of silica, which makes it an effective insulator by limiting the movement of air molecules and heat transfer.
Why is the process of making aerogel difficult and what are the challenges involved?
-Making aerogel is difficult because it involves creating an alcohol-based gel and then drying it without causing it to crack or collapse. The process is sensitive to temperature, pressure, and the rate of drying. Additionally, the handling of chemicals like tetramethyl orthosilicate (TMOS) requires careful safety measures due to its reactivity and potential health hazards.
What are the key steps in making aerogel at home as described in the script?
-The key steps include making an alcohol-based gel using methanol, dilute ammonia, and TMOS, pouring the gel into a mold, allowing it to harden, and then replacing the water in the gel with methanol through a soaking process. The final step involves supercritical drying using liquid CO2 to replace the methanol with air without causing the gel to collapse.
What is supercritical drying and why is it necessary for the production of aerogel?
-Supercritical drying is a process where a substance is dried using supercritical fluid, typically carbon dioxide (CO2). It is necessary for aerogel production because it allows the liquid within the gel to be replaced with a gas without the surface tension that would otherwise cause the gel to collapse. This process avoids the capillary action that leads to cracking and shrinking of the aerogel.
What safety precautions should be taken when handling TMOS?
-When handling TMOS, it is crucial to work under a fume hood to avoid inhalation, and to use personal protective equipment such as gloves and safety goggles to prevent skin and eye contact. TMOS reacts with water to form silica, which can cause permanent blindness if it comes into contact with the eyes.
Why did the creator of the video decide to use a Sous Vide meat cooker for the supercritical drying process in the second attempt?
-The creator decided to use a Sous Vide meat cooker because it offered better temperature control and consistency compared to using a heat gun. The cooker also allowed for a more even heating of the aerogel, reducing the risk of cracking during the supercritical drying process.
What was the main issue the creator faced when trying to load the aerogel into the supercritical dryer?
-The main issue was the fragility of the aerogel. The creator was unsure how to load the aerogel into the chamber without causing damage, as it seemed too delicate to simply drop in and could potentially crack or break.
How did the creator solve the problem of loading and unloading the aerogel from the supercritical dryer?
-The creator made a custom tool inspired by the devices used to load pizzas into an oven. This tool helped to carefully lower the aerogel into the chamber and also to remove it after the process without causing damage.
What was the final outcome of the aerogel produced using the Sous Vide cooker in the second attempt?
-The final aerogel produced using the Sous Vide cooker was largely uncracked and the creator was quite satisfied with the result, considering it to be as close to perfect as possible for the second attempt.
Why did the creator decide to post the behind-the-scenes and more personal content on a separate channel called NileBlue?
-The creator wanted to keep the more personal and behind-the-scenes content separate from the main educational and scientific content. This would allow for a different type of video that could be more fun and less serious, without diluting the primary focus of the main channel.
What are the benefits of using Raycon E25s earbuds as mentioned by the creator?
-The Raycon E25s earbuds offer good bass, a comfortable fit for long-term wear, six hours of battery life, and the ability to use one earbud independently which is useful for safety reasons in a lab setting. They are also affordably priced compared to other premium wireless earbuds.
Outlines
🤔 Introduction to Aerogel and Its Properties
The video begins with the host expressing their fascination with aerogel, one of the lightest materials known. They describe the common type of aerogel made from silica, which is predominantly composed of air. The host explains the material's lightness and its typical use as a thermal insulator due to the trapped air within the silica network that hinders heat transfer. Inspired by videos from Veritasium, the host embarks on a DIY project to create aerogel, starting with making an alcohol-based gel and facing the challenges of obtaining the necessary chemicals and the complexity of the process.
🧪 The Chemistry Behind Creating Aerogel
The host details the process of making the alcohol-based gel, starting with the preparation of dilute ammonia from concentrated ammonia and distilled water. They then mix methanol with dilute ammonia in one beaker and methanol with TMOS in another, combining the two to initiate a reaction that slowly converts TMOS back into silica and forms a gel. The host also discusses the challenges of pouring the delicate gel into a mold without damaging it and their desire to create aesthetically pleasing gels.
🏗️ Building a Mold for Aerogel
The host describes the issues with using traditional molds for the delicate aerogel and shares their creative solution using a plastic cookie cutter, silicone lubricant, a piece of glass, and duct tape to form a makeshift mold. They also discuss the process of creating a wax border and filling the mold with gel before it hardens. The host emphasizes the importance of the mold's design for removing the gel without causing damage and for creating well-defined shapes.
🔄 Soaking and Replacing Water with Methanol
After successfully creating the gels, the host outlines the process of soaking them in methanol for at least a day and then swapping it out for fresh methanol. This step is crucial to remove all water from the gels, which is a slow process taking about a week. The host discusses the wastefulness of this step, requiring a significant amount of methanol, and their plans to recycle it through distillation.
🚫 Avoiding Capillary Action During Drying
The host explains the problems encountered when attempting to dry the gels using conventional methods, such as evaporation, which lead to cracking due to capillary action. They describe the physics behind this phenomenon and the need for a specialized drying method, such as supercritical drying with CO2, to avoid the gel collapsing. The host outlines the process of replacing methanol with liquid CO2, which, when heated and turned supercritical, can be converted to gas without causing damage to the aerogel.
🔧 Constructing a Supercritical Dryer
The host describes the process of building a supercritical dryer, including sourcing specialized high-pressure stainless steel components and sight windows that can withstand high temperatures and pressures. They detail the assembly of the chamber, the challenges of ensuring a leak-free seal, and the testing of the chamber with liquid CO2. The host also discusses their decision to build a larger chamber for better footage and easier gel handling.
🔬 Supercritical Drying Process and Results
The host narrates the supercritical drying process, emphasizing the slow and careful introduction of liquid CO2, the gradual heating to the supercritical point, and the slow depressurization to remove the CO2 without causing damage to the aerogel. Despite some cracks in the final product, the host is pleased with their first attempt at creating aerogel. They also share their conclusion that the process is laborious and time-consuming and their intention to attempt it again using a Sous Vide cooker for more consistent heating.
🍽️ Using a Sous Vide Cooker for Aerogel
The host describes their second attempt at creating aerogel using a Sous Vide cooker, which allows for more precise and even heating. They detail the process of loading the gel into the chamber, using liquid CO2 to replace the methanol, and slowly heating the chamber to supercritical temperatures. The host is excited to find the resulting aerogel uncracked, although slightly yellow, and shares their satisfaction with the outcome, despite the long and challenging journey to achieve it.
🎥 Reflecting on the Project and Future Plans
In the final paragraph, the host reflects on the emotional and physical toll of working on such an intensive project, which led to a desire to focus on smaller, less demanding projects. They discuss their decision to hire a cameraman and editor to capture more behind-the-scenes content and share more of the fun side of practical science on a secondary channel, NileBlue. The host also expresses gratitude to their Patreon supporters and sponsors, particularly Raycon, for their ongoing support and mentions a discount link for Raycon's wireless earbuds.
Mindmap
Keywords
💡Aerogel
💡Silica
💡Thermal Insulator
💡Tetramethyl Orthosilicate (TMOS)
💡Methanol
💡Supercritical Drying
💡Capillary Action
💡CO2 Supercritical Fluid
💡Sous Vide
💡Heat Gun
💡Raycon
Highlights
Aerogel is one of the lightest-known materials with potential uses as a thermal insulator due to its air-trapping silica network.
The process of making aerogel involves creating an alcohol-based gel and drying it, which is simpler in theory than in practice.
Tetramethyl orthosilicate (TMOS), a liquid source of silica, is a key but dangerous chemical in aerogel production that can cause permanent blindness.
The author's preferred method for making aerogel involved a recipe from aerogel.org, using methanol, concentrated ammonia, and TMOS.
A unique mold-making technique using a plastic cookie cutter, silicone lubricant, and melted wax was developed to shape the aerogel.
The aerogel's extreme fragility required a careful handling process, including a method to load and unload the gel without damage.
Supercritical drying with CO2 is a specialized method used to dry the aerogel without causing it to collapse due to capillary action.
The author built a high-pressure stainless steel chamber for supercritical drying, sourced from a specialized supplier due to the process's requirements.
A high level of precision and safety measures were necessary when handling liquid CO2, including slow filling and depressurization.
The use of a Sous Vide meat cooker for temperature control during the supercritical drying process was a novel approach by the author.
The final aerogel product was nearly perfect despite some cracks, representing a significant achievement for a complex DIY project.
The entire aerogel production process was labor-intensive, time-consuming, and required constant monitoring.
The author's experience with aerogel production influenced a shift towards smaller, less demanding projects and a new video series on NileBlue.
Raycon wireless earbuds were highlighted as a sponsor product that the author found useful for their work in the lab.
The video concludes with a call to support the author's work on Patreon for early access to videos and additional content.
Transcripts
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