For the last two decades, many polymers have been tested to increase CO2 viscosity for enhanced oil recovery using CO2 (CO2-EOR). Unfortunately, conventional HC-polymers were inactive for viscosity enhancements due to their poor solubility in supercritical CO2 (scCO2). Recent SANS studies (RB1610015 and RB1720361) found FC-HC amphiphiles to form HC-core/FC-shell aggregates, which could also solubilize custom-made CO2-philic HC-polymers in scCO2. The aggregates were elongated with adding the HC-polymers, or also introducing hydrogen bonding groups. To develop inexpensive HC-polymer-based CO2-thickners for CO2-EOR, this proposed SANS experiment will examine formation of 3D-structured polymer networks in scCO2 by mixing cheap and conventional HC-polymers, amphiphiles, and cross-linkers. It will provide important information and enable the development of inexpensive CO2-thickeners.