Author: Sarah K. Ikerd, Studio Shangri-La, sarah.ikerd@studio-shangri-la.com
Abstract: In response to the urgent need for sustainable solutions to plastic waste, this study explores a novel home-safe photocatalysis process aimed at converting plastic waste into primarily water and hydrogen gas. Leveraging principles of redox chemistry and UV light irradiation, the process demonstrates promising results in experiments, with potential implications for overall waste reduction and environmental remediation. The importance of this research lies in its potential to address the pressing issue of plastic pollution while offering a non-toxic and accessible method for waste management at the household level. By challenging existing paradigms and applying innovative technologies, this study contributes to the ongoing efforts to create a more sustainable future. Further experimentation and refinement of the process are underway, with implications for scalable implementation and real-world application. This research underscores the value of interdisciplinary approaches and grassroots innovation in addressing global environmental challenges.
Methods & Results:
Thus far the early stage results of photocatalysis for PET and PETE plastic are promising with results from both steady and flashing UV-A black lights at 380-400 nm, 20W per light, for 30 minutes. The two 120 degree beam lights were placed on either side of the bottle, and surrounded by galvanized steel and aluminum in two different types of enclosures so far, a trunk and a shelf. Part of the goal is versatility and safety, so there are number of constraints that have to be satisfied, such as not having to be airtight, especially to adapt this to trash receptacles of different kinds. The most recent iteration of the lights is that they are also waterproof and cordless.
Going forward, the process needs bandwidth that covers UV-A, B and C, and enhancement of the following factors in order to be truly successful with different materials:
- Strength / Power of the lights
- Timing / Rhythm of the flashing
- Variability / Different Configurations or Patterns of the lights
An effective circular ‘trash can of the future’ will need to contain a photochemical process that has different settings, so a grid or matrix of lights, that could adapt combing sweeps through the corresponding bands of the electromagnetic spectrum needed for the materials.
For PET, a common plastic, the known degradation wavelength is around 300-330 nanometers, and this varies for other types of plastics. And the UV range matches this, and so this is a great starting point. And there are other advantages to employing UV-C, because it is known for removal of VOCs, HCHO (formaldehyde) and Carbon Dioxide. In other words, it neutralizes some potential toxicity. During one test so far, UV-C was included and there was a marked improvement in air quality both inside and outside the container. The manner of photomixing and strength of the lights will definitely be modified going forward, though.
Discussion:
Eventually, the device sequence would need to activate the electronic excitations necessary to facilitate nuclear transmutations, that coalesce into harmless and beneficial byproducts such as Water, Hydrogen, Vinegar and Sugar. In the grand cosmic scheme, even a stubborn-to-degrade chain of polymers like Polypropylene is not too many degrees removed from the elements Hydrogen, Oxygen and Carbon. And although the chemical properties of the phases of water are complex, it is structurally simple.
A general formula that leaves room for more experimentation at this stage is:
C10H8O4 (PET) + nH2O + UV light [+ Catalyst] -> xH2 + yH2O
Here is a longer pathway:
C10H8O4 (PET) + nH2O + UV light + Catalyst ->
Resulting in:
C6H12O6 (sugar) + C2H4O2 (acetic acid) + H2 (hydrogen gas) + H2O (water)
There the byproducts are sugar, vinegar, hydrogen and water.
A possible further transformation of sugar is as follows:
C6H12O6 + 6O2 -> 6CO2 + 6H2O
And for acetic acid:
C2H4O2 + 2O2 -> 2CO2 + 2H2O
Water is a highly desirable byproduct, and the LED sheets or arrays should be waterproof to accommodate, and the sheets applied with a radiation resistant bioadhesive inside a radiation safe (outer) and reflective (inner) container. Given the different settings, there could also be a connected software program in the future. This depends on how effective the main sequence becomes. That is, running the most effective photochemical light combination that would morph or irradiate one polymer chain into another or others, effectively bypassing potentially toxic states, creating favorable redox reactions.
Redox reactions involve the transfer of electrons between reactants. Within this context of PET degradation — all of this is based on the concept of optimizing redox reactions to break down the polymer chains and produce from them simpler molecules by photoexcitation. Another wonderful example of this leaping phases concept already being put to use is flash graphene, which converts waste by fast high temperature or “flash joule” vaporization.(1)
Conclusions:
And it may beneficial considering other possibilities within this set of experiments, like calculating the triple point — or the temperature and pressure at which the solid, liquid, and gas phases of a substance coexist in equilibrium. By utilizing the conditions near the triple point, that could potentially facilitate decomposition into water and hydrogen gas. Something else to consider is adding a catalyst such as metal oxide. Also, molecular resonance and acoustic techniques.
Going even further out, to consider the light matrix as a way of patterning or training what the molecules synthesize, such as by flashing the shape sequence of the macromolecule as an entrainment code, followed by flashing the sequence of the destination molecule.
There are many next steps to take, yet is a compelling point to report findings. Next, in addition to equipment acquisition and further testing, it may be helpful mapping out electron orbitals and how they interact with the light, to make the energetic leaps for transformation, thereby elucidating photochemical pathways and better understanding the underlying mechanisms.
Despite there being numerous possibilities, the overall direction is to keep the device process as simple and streamlined as possible, to what will logically be most efficient. And any discoveries and observations along the way, such as the entrainment or syncing that occurred between the two lights, make the venture that much more valuable.
Precision optics and bioelectronics hold tremendous promise not only for advanced waste management, but also many other leading-edge technologies like tissue regeneration for regenerative medicine, unlocking a new dimension of sustainable synergy and understanding.
- “Gram-scale bottom-up flash graphene synthesis“ | Duy X. Luong, Ksenia V. Bets, Wala Ali Algozeeb, Michael G. Stanford, Carter Kittrell, Weiyin Chen, Rodrigo V. Salvatierra, Muqing Ren, Emily A. McHugh, Paul A. Advincula, Zhe Wang, Mahesh Bhatt, Hua Guo, Vladimir Mancevski, Rouzbeh Shahsavari, Boris I. Yakobson & James M. Tour | Nature 2020 | https://www.nature.com/articles/s41586-020-1938-0