PDF Publication Title:
Text from PDF Page: 017
CARBON DIOXIDE TECHNOLOGY PLATFORM 131 4. APPLICATION OPPORTUNITIES ENABLED BY THE DESIGN OF SURFACTANTS FOR CO2 4.1 Dispersion Polymerizations The relative insolubility of many industrially important polymers in supercritical CO2 necessitates the use of heterogeneous polymerization techniques. Conven- tional heterogeneous dispersion polymerizations of unsaturated monomers are performed in either aqueous or organic dispersing media with the addition of interfacially active agents to stabilize the colloidal dispersion that forms. Suc- cessful stabilization of the polymer colloid during polymerization results in the formation of high molar mass polymers with high rates of polymerization. A sim- ilar analogy applies to dispersion polymerization in CO2 where stabilization has been accomplished with the aide of nonionic-homopolymers (15, 34–40), block copolymers (34, 37–43), and reactive macromonomer surfactants (22a,b; 39; 40; 45). Supercritical CO2—in conjunction with free radical initiators and specifically designed, interfacially active, stabilizers—is an environmentally responsible al- ternative to aqueous and organic dispersing media for heterogeneous dispersion polymerizations. Typically, a free radical dispersion polymerization in supercritical CO2 starts as a one-phase, homogeneous system such that both the monomer and the polymeriza- tion initiator are soluble in the polymerization medium. As the reaction progresses, the resulting growing polymer phase separates into primary particles. Amphipathic molecules—mediators that prevent particle flocculation and aggregation—present in the system stabilize these primary particles. Polymer colloids produced by dis- persion polymerizations are usually stabilized by a steric mechanism rather than an electrostatic mechanism that is common to colloidal stabilization in aqueous environments (15). Steric stabilization of a colloidal dispersion is usually imparted by amphipathic macromolecules that become adsorbed onto the surface of the dis- persed phase. These amphipathic macromolecules contain an anchoring segment that attaches to the particle (usually by physical adsorption), and stabilizing moi- eties that are soluble in the continuous phase. The stabilizing moieties project into the continuous phase (which needs to be a good solvent for the stabilizing moieties) and prevent flocculation by mutual excluded volume repulsions during a Brownian collision, thereby imparting stability to the colloid. Conventional lipophilic monomers, exemplified by methyl methacrylate, can be quantitatively (>90%) polymerized heterogeneously to very high conversion in supercritical CO2. This polymerization proceeds in the presence of poly(FOA) resulting in kinetically stabile dispersions of micrometer-sized particles with a narrow size distribution (15). The amphiphilic activity exhibited by poly(FOA) suggests that environmentally responsible CO2 is a viable replacement for the sol- vent traditionally used in heterogeneous polymerizations and lays the foundation for surfactant-modified, CO2-based separations processes.PDF Image | OPPORTUNITIES FOR POLLUTION PREVENTION
PDF Search Title:
OPPORTUNITIES FOR POLLUTION PREVENTIONOriginal File Name Searched:
Ann._Review_Ener.Environ.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)