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Substantial defluorination of chlorinated PFCAs

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Catalysts For Aqueous Contaminant Reduction

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Pulsed Laser Deadhesion

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Upcycling Waste Polyvinyl Chloride (PVC) To Prepare Value-Added Dienes

Making productive use of PVC waste is a challenge. Mechanical recycling is difficult because different PVC products each contain different blends of plasticizers, stabilizers, and other additives; combining these additives leads to diminished mechanical properties.Meanwhile, incineration of PVC is an issue because it produces corrosive HCl and toxic chlorinated dioxins, a class of persistent organic pollutants. Changing regulations also present an issue: harmful plasticizers such as diethylhexylphthalate (DEHP) still present in legacy PVC products are now banned in newly made (or newly recycled) PVC in the EU. In the US, DEHP is restricted in childcare articles and food packaging. Vinyloop®, a plant designed to recycle PVC from mixed waste by selective dissolution/precipitation, was shut down in 2018 due to its inability to remove phthalates.  Lead stabilizers found in legacy PVC products are similarly banned in new products, complicating recycling. Chemical recycling and upcycling of polymers is a growing field of interest with the goal of creating a circular economy. Breaking down a polymer into monomer or other useful small molecules allows purification of the products and avoids the downcycling phenomenon seen in mechanical recycling. Polymers with labile ester or amide bonds in their backbone are more amenable to this treatment than polymers with an all-carbon backbone. For instance, polyethylene terephthalate and polyurethane can both be depolymerized by hydrolysis, alcoholysis, or aminolysis; the monomers or short oligomers obtained can be repolymerized to form the original polymer or other high-performance polymers. Polymers with all-carbon backbones are more challenging to controllably cleave, but many methods have been developed to break down polyethylene, polypropylene, and polystyrene into light hydrocarbon fuels, benzene derivatives, or H2 gas. However, even small amounts of PVC can contaminate these reactions and deactivate the catalyst, requiring PVC to be separated out first.  Chemical upcycling of PVC is underdeveloped compared to that of other polymers, despite the fact that it is the third-most produced plastic in the world. Most PVC degradation procedures explored have been carried out at high temperatures (200-900 oC) and focus on pyrolysis to small hydrocarbons or oxidation to carboxylic acids. Pyrolysis of PVC is complicated by the release of HCl, which can corrode the equipment and deactivate catalysts. Solutions to this include pre-treatment with base, or pyrolysis in the presence of base or bio-waste. In some cases, products are a mixture of acetone, benzene, and other aromatics. In other cases, alkanes or syngas (CO and H2) are produced. There remains a need for new approaches to chemically break down PVC. Expanding the toolbox of reactions that can controllably degrade PVC will allow a wider range of products to be made, and bring the world closer to the goal of harvesting plastic waste as a resource. 

Hyperthermophilic Single-Peptide For Deconstruction Of Crystalline Cellulose

Cellulose, the major component of plant biomass, is considered the most abundant biopolymer. Certain microorganisms are able to convert the monomer of cellulose, glucose, into various products useful in the production of biofuels and other methods. Cellulose is highly stable, has a high storage potential, low cost, and plentiful supply. Based on these and other properties, cellulose and enzymes capable of degrading and hydrolyzing it are useful in the sequestration, storage, and production of bioenergy.  Crystalline cellulose is composed of linear polymers of β1-4 linked glucose, held in a tightly crosslinked crystalline lattice by a high degree of intermolecular hydrogen bonding. This structure confers stability but also hinders efficient deconstruction of cellulose. Strategies for commercial depolymerization of cellulose typically combine pretreatment to disrupt the crystalline structure, followed by enzymatic hydrolysis. Disruption of the crystalline structure and chemical hydrolysis typically requires high temperatures and low pH. Enzymatic hydrolysis generally occurs under milder conditions. The degree of pretreatment required and the expense of subsequent cleanup steps are affected by properties of the enzymes used. Bacteria capable of degrading cellulose include those belonging to the genera Aquifex, Rhodothermus, Thermobifida, Anaerocellum, and Caldicellulosiruptor. A recombinant thermostable endoglucanase of Aquifex aeolicus produced in E. coli showed maximal activity at 80° C. and pH 7.0 with a half-life of 2 h at 100° C.  UC Berkeley investigators have engineered a polypeptide having cellulase activity for hydrolysis and degradation of cellulose-containing biomass.

Determining Reservoir Properties

Determining the properties that control fluid flow and pressure migration through rocks is essential for understanding groundwater, energy reservoirs and fault zones. Hydraulic diffusivity is the key parameter that controls pressure migration in reservoirs. There is a need to determine it in situ for energy, groundwater and earthquake applications. Direct measurements of these properties underground generally require expensive and invasive processes such as pumping large volumes of water in or out of the ground. Most current methods rely on either active pumping between wells or proxies such as seismic velocity or the migration time of microseismicity. These conventional methods may change the structure that they are trying to measure and do not resolve variations in space without complex, multiple experiments. Moreover, active pumping is expensive, invasive and sensitive to a limited set of scales, while proxies are difficult to calibrate.

Robust Low-Cost Air Diffusion Cathodes For Water Treatment

Gas diffusion electrodes are used in electrochemical applications to produce value added chemicals such as H2O2. Carbon paper and carbon cloth are used as substrates in gas diffusion cathodes. However, carbon-based substrates are not mechanically sturdy as they can develop cracks under flexion. They are also expensive ($150 for a 310-micron thick carbon paper of 40cm X 40cm). UC Berkeley researchers have created air-cathodes made with a non-reacting metal mesh as the supporting conducting substrate. The metal may be in the form of an alloy or coating, such as one metal on another, or a metal coating on a non-metal substrate.  The metal air cathodes avoid the use of carbon paper altogether, are more cost effective, flexible yet strong and durable, and provide robust gas-diffusion cathodes for sustained production of H2O2 over long-periods of operation.  

Dehydrogenation And Isomerizing Ethenolysis Of Polyethylene

 This invention is a method includes mixing a polymer with one or more dehydrogenating reagent(s), thereby forming the dehydrogenated polymer.  Such a dehydrogenated polymer can then be made into a alkene or a dehydrogenating polymer.

A High Capacity Reusable Cationic Material [Ag-Bipy+] [No3] For The Removal Of Perchlorate From Water

Perchlorate is a chemical usually produced commercially that is soluble in water, can easily travel through aqueous systems, and can persist for decades in groundwater. Even in trace amounts, perchlorate can disrupt thyroid hormone production, which can have harmful side effects.  These particular characteristics have made contamination of ground water by perchlorate a major widespread issue, and its decontamination a major challenge. Currently available techniques for removing perchlorate include high pressure water washout and single-use resins for capturing perchlorate.

Determination Of The Optimal Fluid Pulses For Enhancement Of Reservoir Permeability And Productivity

Oil and natural gas extraction techniques commonly rely on hydraulic fracturing to induce and/or improve fluid flow in low permeability rocks. Hydraulic fracturing can be environmentally costly though as it uses a variety of materials, including chemicals and solids, injected into the ground to mechanically fracture and artificially maintain cracks in the subsurface. A UC Santa Cruz researcher has developed a method that uses site-specific reservoir properties to determine the best frequency of forcing to clear fractures and increase fluid flow with pressure oscillations. 

High Fidelity 3D Printing Through Computed Axial Lithography

The inventor has developed novel algorithms and metrology methodologies, including real-time in-situ imaging of part formation, in computed axial lithography printing (CALP). CALP is a form of continuous 3D roll-based additive manufacturing which is distinct from roll-based micro/nanomanufacturing methods such as imprint lithography, gravure printing, and photo-roll lithography because it enables production of high aspect ratio reentrant features and voids in a single step that are difficult or even impossible with the existing methods.

A Novel Catalyst for Aqueous Chlorate Reduction with High Activity, Salt Resistance, and Stability

Inspired by biological systems, Prof. Jinyong Liu’s lab at UCR has developed a novel heterogeneous, bimetallic catalyst MoOx-Pd/C. The catalyst contains earth-abundant molybdenum (Mo) and the carbon support of Pd/C has a high capacity to accomodate MoOx species. The incorporation of a MoVI yields a highly active and robust catalyst. The porous carbon mimics the enzyme protein pocket (of microbes) to accommodate the oxygen atom transfer metal site. The representative figures shown below demonstrate the high activity and robustness of the catalyst for both chlorate and perchlorate reduction. The effect of concentrated salts on the reduction of 1 mM ClO3− by the MoOx-Pd/C catalyst at a loading of 0.2 g/L. The reactions were conducted at 25 oC and under 1 atm H2. Chlorine balance for ClO4- reduction Fig. 3 shows the profiles of the reduction of 0.18M ClO3− spikes in a multiple-spike reaction series. The decrease of activity was only caused by the gradual build-up of concentrated Cl− (see details in the publication).  

High Performance Iron Electrocoagulation Systems for Removing Water Contaminants

The inventors have developed an iron electrocoagulation (Fe-EC) system for arsenic removal. The system offers a highly effective, low cost, robust method for removing arsenic from groundwater used for drinking, at community scale (10,000 liters per day).The main advance of this invention is to replace the assembly of inter-digited flat steel plates with an assembly of spiral-wound or folded and inter-digited two steel sheets separated only with perforated insulating spacers. This substantially reduces the energy consumption in comparison to other Fe-EC reactors, and allows for larger flow rates for a given reactor size than the standard inter-digited flat plate configuration. This advance is possible because the system relies on: externally added (ppm quantities) of oxidizer (H2O2), and a newly-discovered effect that allows consistent iron dissolution at high current densities. High current density also produces copious quantities of micro-bubbles of H2 gas, which flushes the space between the electrodes continuously during operation, preventing the clogging that has defeated earlier attempts.In a typical Fe-EC reactor, parallel inter-digited plates of mild steel are inserted into the contaminated water and a small DC voltage is applied between alternate plates to promote anodic dissolution of F(0) metal to release Fe(II) ions into the contaminated water. The Fe(II) ions react with dissolved oxygen in the water to produce Fe(III) that is used to capture the contaminants. Typically, an assembly of flat inter-digited parallel steel plates, with nearest neighbor spaced 2 cm to 5 cm, is used in Fe-EC reactors. Occasionally, externally added or in-situ produced oxidants may be used (e.g. externally added strong oxidants such as H2O2, O3, Chlorine, Permanganate, etc., or in-situ produced strong oxidants such as H2O2 using carbon based cathodes). 

Buffer-Free Process Cycle For Co2 Sequestration And Carbonate Production From Brine Waste Streams With High Salinity

Researchers in the UCLA Department of Civil and Environmental Engineering have developed a novel process cycle to separate and enrich divalent cations such Ca2+ and Mg2+ from high salinity brine solutions for CO2 mineralization.

System and Method for Flexible Low-Energy Membrane-Based Liquid Purification

UCLA researchers in the Department of Chemical and Biomolecular Engineering have developed a platform and method for membrane-based water purification and desalination that combines operational flexibility with energy efficiency, allowing effective treatment and desalination of raw feed water over a wider range of solute concentrations and product recovery.

Optimizing A Mixed Microbial Community For Biodegradation Of Halogenated Solvents And 1,4-Dioxane

UCLA researchers in the Department of Civil and Environmental Engineering have formulated a microbial community that degrades halogenated solvents and their stabilizers in water resources.

Biomass-Derived Polymers And Copolymers Incorporating Monolignols And Their Derivatives

UCLA researchers in the Departments of Bioengineering, Chemistry and Biochemistry have developed a novel synthetic strategy for the fabrication of biomass-derived polymers incorporating underutilized lignin derivatives.

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