Going supercritical.

NileBlue
24 Jan 202019:53
EducationalLearning
32 Likes 10 Comments

TLDRThe script documents a personal journey of exploring aerogel and supercritical CO2. The narrator, intrigued by aerogel's unique properties, experiments with a pressure chamber to visualize the phase change of CO2. Despite initial setbacks with leaks and a malfunctioning pressure gauge, the process successfully demonstrates the transition of CO2 from solid to liquid and eventually to a supercritical state. The experiment also investigates the interaction of supercritical CO2 with silica beads, revealing unexpected coloration and structural changes. The video concludes with the narrator's reflections on the experience and future plans to create aerogel and explore other applications of supercritical fluids.

Takeaways
  • ๐Ÿ”ฌ The script describes an individual's journey of interest in aerogel, leading to the purchase and experimentation with this lightweight, blue-hazy material.
  • ๐Ÿ›’ Despite the high cost, the individual bought a small square of aerogel and was fascinated by its lightness and hazy appearance.
  • ๐Ÿ’ก After playing with the aerogel, the individual decided to attempt making it, researching the use of supercritical fluids, particularly supercritical CO2, in its production.
  • ๐Ÿ“š The script explains the concept of supercritical fluids, where the liquid and gas phases of a substance merge beyond a certain temperature and pressure known as the critical point.
  • ๐Ÿ” The individual struggled to visualize supercritical fluids until watching videos by Ben from 'I'd Applied Science', who demonstrated the phase change using a custom-built pressure chamber.
  • ๐Ÿค Ben generously provided the individual with a pressure chamber, enabling them to experiment with supercritical CO2 firsthand, despite the inherent risks.
  • โš™๏ธ The process of preparing the chamber involved adding dry ice, securing the chamber, and ensuring it was tightly sealed to avoid leaks.
  • ๐ŸŒก๏ธ The individual faced challenges with the pressure gauge, which initially failed to register increasing pressure, but later showed readings once replaced.
  • ๐ŸŒ€ The script details the heating process to achieve the supercritical state, observing changes in the CO2 as it transitioned from liquid to gas and eventually to a supercritical fluid.
  • ๐Ÿ”ฎ The individual discovered that supercritical CO2 could cause silica beads to crack and exhibit an opalescent effect, possibly due to thin-film interference.
  • ๐Ÿšซ The chamber was not suitable for making aerogel or extracting caffeine from coffee due to the limitations of the O-ring and the need for higher pressures and soak times.
  • ๐Ÿ”„ The individual replaced the broken pressure gauge and observed the pressure changes during the supercritical process, noting the cloudiness that occurred as pressure dropped below critical thresholds.
Q & A
  • What is aerogel and why is it interesting to the narrator?

    -Aerogel is a material known for its extremely low density and unique properties, such as being a superb insulator. The narrator finds it interesting due to its unusual characteristics like its lightness and hazy, blue appearance, and is intrigued by the process of making it.

  • Why did the narrator decide to make their own aerogel?

    -The narrator was fascinated by the properties of aerogel and wanted to understand the process behind its creation. After playing around with a purchased sample, they were motivated to attempt making it themselves.

  • What is a supercritical fluid and how is it used in making aerogel?

    -A supercritical fluid is a substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist, and the substance can diffuse through solids like a gas and dissolve materials like a liquid. In aerogel production, supercritical CO2 is commonly used to remove the liquid from a gel, leaving behind the solid network that forms the aerogel.

  • Who is Ben from I'd Applied Science and how did he assist the narrator?

    -Ben is the creator of a pressure chamber designed to demonstrate the phase change of CO2 to a supercritical state. He assisted the narrator by providing them with his pressure chamber free of charge to experiment with and visualize the supercritical process firsthand.

  • What were the initial difficulties the narrator faced when using the pressure chamber?

    -The narrator initially struggled with properly sealing the chamber to prevent leaks, which was crucial for the experiment. They also had issues with the pressure gauge not functioning correctly, making it difficult to monitor the pressure during the experiment.

  • How did the narrator test for leaks in the pressure chamber?

    -The narrator tested for leaks by closing the valve and allowing the pressure to build up as the dry ice melted into liquid CO2. They observed for hissing noises and white gas escaping, which would indicate a leak.

  • What is the critical point and how does it relate to the phase change of CO2?

    -The critical point is the temperature and pressure at which the distinct liquid and gas phases of a substance merge into a supercritical phase. For CO2, this occurs at a temperature of about 31ยฐC and a pressure of around 73 atmospheres. Beyond this point, CO2 can exist as a supercritical fluid.

  • How did the narrator visualize the transition of CO2 from a liquid to a supercritical fluid?

    -The narrator used a hairdryer to heat the liquid CO2 in the pressure chamber, observing the changes in the appearance of the CO2 as it warmed up, boiled, and eventually turned into a hazy substance without a clear separation between liquid and gas, indicating the supercritical state.

  • What experiment did the narrator conduct with silica beads in the supercritical CO2?

    -The narrator placed silica beads in the chamber with dry ice and allowed the CO2 to become supercritical. They observed the behavior of the beads, noting that they remained mostly stationary, indicating the presence of the supercritical fluid, and also noticed the beads had changed in appearance, becoming cracked and displaying an opalescent sheen.

  • What were the narrator's plans for future experiments involving the pressure chamber?

    -The narrator expressed interest in using the pressure chamber to make aerogel on a larger scale and to attempt creating decaf coffee or large-scale colored silica beads. They also mentioned building a proper chamber for higher pressures and longer soak times needed for these experiments.

  • Why was the video about the supercritical CO2 experiments posted on Niall Blue instead of Niall Red?

    -The narrator felt that the content of the video did not fit the theme of large and weird projects that are typically featured on Niall Red. They decided to post it on Niall Blue to share the fun and informative project without wasting the effort put into filming it.

Outlines
00:00
๐Ÿ›’ Discovering Aerogel and the Supercritical CO2 Process

The narrator's fascination with aerogel began about a year and a half ago, leading to a purchase of a small, lightweight, and oddly hazy blue square of the material. Intrigued by its properties, they researched the production process, focusing on the use of supercritical fluids, particularly CO2. After learning about the concept of supercritical fluids and the phase changes involved, they reached out to Ben from 'Applied Science' who generously provided a pressure chamber for hands-on experimentation. The initial attempts to create supercritical CO2 involved adding dry ice to the chamber and sealing it, but faced issues with leaks and the pressure gauge's malfunction. Despite the setbacks, the narrator gained a better understanding of the process and the safety precautions involved.

05:01
๐Ÿ”ฌ Experimenting with Supercritical CO2 and Phase Changes

The narrator continued their experiments by closing the chamber valve to increase pressure and observing the melting of dry ice into liquid CO2. They noted the phase diagram of CO2, indicating the appearance of the liquid phase at five times atmospheric pressure. Despite a non-functional pressure gauge, they relied on temperature readings to monitor the process. Heating the chamber with a hairdryer, they observed the transition of liquid CO2 into a supercritical state, characterized by a hazy appearance and the inability to distinguish between liquid and gas phases. The supercritical CO2 was then cooled to revert back to liquid form, demonstrating the reversible nature of the phase change. The narrator expressed a desire to explore the supercritical state further, particularly its interaction with solid objects.

10:02
๐Ÿ”ฎ Exploring Supercritical CO2 with Silica Beads

In a follow-up experiment, the narrator introduced silica beads into the chamber along with dry ice, observing their behavior as the CO2 transitioned to a supercritical state. The beads remained relatively stationary, suggesting the presence of a fluid with liquid-like properties. Upon agitation, the beads moved minimally, indicating resistance similar to that in a liquid. The rapid release of pressure caused the beads to exhibit colorful, opal-like reflections, possibly due to thin-film interference within the cracks created by the supercritical CO2. The narrator was intrigued by this unexpected result and considered further investigation into the phenomenon.

15:04
๐Ÿ”„ Reflections on Supercritical CO2 Experiments and Future Plans

The narrator reflected on their experiences with supercritical CO2, having gained a deeper understanding of its properties and behavior. They replaced the broken pressure gauge to monitor the pressure changes more accurately, noting the cloudiness that occurred as the pressure dropped below critical levels. The narrator also discussed the limitations of their current setup for more demanding applications like aerogel production or caffeine extraction, hinting at the need for a more robust chamber design. They shared their future plans to create a proper high-pressure chamber for these purposes and possibly explore the creation of large-scale colored silica beads. The video concluded with an acknowledgment of Patreon supporters and a note on the decision to publish the video on 'Niall blue' instead of the main channel, 'Niall red', due to thematic differences.

Mindmap
Keywords
๐Ÿ’กAerogel
Aerogel is a low-density material known for its unique properties such as being extremely light and having a hazy, blue appearance. In the video, the creator expresses fascination with aerogel, leading to the purchase of a sample and an eventual desire to create it. Aerogel is central to the theme of the video as it is the material the creator wants to produce using supercritical fluids.
๐Ÿ’กSupercritical Fluids
Supercritical fluids are substances at a temperature and pressure above their critical points, where distinct liquid and gas phases do not exist, and the substance can diffuse through materials like a gas while dissolving materials like a liquid. In the script, the creator discusses the concept of supercritical fluids, particularly supercritical CO2, as a crucial component in the aerogel production process.
๐Ÿ’กCritical Point
The critical point is the temperature and pressure at which the distinction between the liquid and gas phases of a substance disappears, resulting in a supercritical fluid. The video script describes the process of reaching the critical point with CO2, highlighting the phase change from liquid to supercritical fluid, which is a key part of the experiment.
๐Ÿ’กDry Ice
Dry ice is the solid form of carbon dioxide (CO2) and is used in the video as the starting material for creating supercritical CO2. The script mentions packing the pressure chamber with dry ice, which then sublimates to form liquid CO2, an essential step in achieving supercritical conditions.
๐Ÿ’กPressure Chamber
A pressure chamber is a device designed to contain and withstand high pressures, used in the video to create supercritical CO2 by heating and pressurizing dry ice. The script details the process of using a pressure chamber built by Ben from 'I'd applied science,' which the creator received for free to conduct the experiment.
๐Ÿ’กPhase Diagram
A phase diagram is a graphical representation showing the equilibrium conditions between different states of matter (solid, liquid, and gas) under varying temperature and pressure. The script refers to the phase diagram for CO2 to illustrate the process of transitioning from solid dry ice to liquid CO2 and eventually to a supercritical state.
๐Ÿ’กThermocouple
A thermocouple is a temperature measurement device consisting of two dissimilar metals that produce a voltage proportional to the temperature difference between their ends. In the video, a thermocouple is used to monitor the temperature inside the pressure chamber, which is critical for achieving the supercritical state of CO2.
๐Ÿ’กSupercritical CO2
Supercritical CO2 is carbon dioxide in its supercritical state, which has unique properties that allow it to act as both a liquid and a gas. The script describes the process of turning dry ice into supercritical CO2 by heating and pressurizing it, which is a central part of the experiment and relates to the video's theme of exploring the properties of supercritical fluids.
๐Ÿ’กSilica Beads
Silica beads are small, solid particles made of silicon dioxide, used in the video to demonstrate the interaction of a solid with supercritical CO2. The script describes an experiment where silica beads are placed in the pressure chamber with supercritical CO2, showing how the beads behave differently in the supercritical fluid compared to a regular liquid.
๐Ÿ’กInterference
Interference is a phenomenon in physics where waves superpose to form a resultant wave of greater, lower, or the same amplitude. In the script, the creator observes colorful reflections on cracked silica beads after exposure to supercritical CO2, suggesting that interference might be occurring due to thin film effects caused by the cracks.
๐Ÿ’กPatience and Persistence
Throughout the script, the creator demonstrates patience and persistence in their experimentation with supercritical CO2. Despite initial failures and challenges, such as leaks and a broken pressure gauge, the creator continues to refine their approach and learn from each attempt, embodying the spirit of scientific inquiry and perseverance.
Highlights

Individual purchased aerogel due to interest despite its high cost, noting its lightness and unique hazy blue appearance.

The individual decided to make aerogel and researched the use of supercritical fluids, particularly supercritical CO2, in its production.

Supercritical fluids, especially supercritical CO2, have no distinct liquid or gas phase and act as a hybrid of both.

Ben, from 'I'd applied science', provided a pressure chamber to observe the supercritical phase change of CO2, free of charge.

The pressure chamber was used to experiment with CO2, observing its phase changes from solid to liquid and eventually to a supercritical state.

Safety concerns were addressed with the pressure chamber, acknowledging its potential to explode but ensuring precautions were taken during experiments.

Dry ice was used to create liquid CO2 within the chamber, with care taken to avoid leaks and ensure proper sealing.

The importance of correctly tightening the chamber to avoid leaks or added stress to the acrylic windows was emphasized.

Observations of the phase change included the melting of dry ice into liquid CO2 and the subsequent increase in pressure within the chamber.

A malfunctioning pressure gauge led to the reliance on temperature monitoring to achieve the supercritical state.

The supercritical state of CO2 was achieved by heating the chamber to approximately 30ยฐC, causing the liquid CO2 to boil and expand.

The transition to a supercritical state resulted in a hazy appearance and a color reminiscent of aerogel.

Supercritical CO2 was demonstrated to revert to liquid CO2 by cooling the chamber, a process inspired by Ben.

Silica beads were used to illustrate the interaction between a solid object and supercritical CO2, showing the beads remained mostly stationary.

Shaking the chamber with supercritical CO2 and silica beads created turbulence, indicating the presence of a fluid.

Silica beads exhibited coloration and cracks after interaction with supercritical CO2, suggesting a possible thin film interference effect.

The individual replaced the broken pressure gauge to accurately monitor pressures during the supercritical CO2 process.

The process of making aerogel and extracting caffeine from coffee with supercritical CO2 was deemed impractical with the current setup due to required higher pressures and soak times.

The individual has since built a proper high-pressure chamber for making aerogel and other supercritical CO2 applications.

The video was posted on Niall blue instead of the main channel due to a decision to dedicate the main channel to larger and more unusual projects.

Transcripts
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