Details

Autor(en) / Beteiligte

• Hao, Xiang
• Leng, Zejian
• Wang, Hairong
• Peng, Feng
• Yan, Qiang

Titel

CO 2 -switchable non-Newtonian fluids

Ist Teil von

• Green chemistry : an international journal and green chemistry resource : GC, 2020-06, Vol.22 (12), p.3784-3790

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Fluidic materials that exhibit an engineered non-Newtonian response are highly desirable in industrial and military applications. For example, shear thickening is highly intriguing in the case of flexible body armor or damping devices; however, shear thinning is more suitable in industrial processes with confining flow or painting. Herein we present a new class of non-Newtonian polymeric fluids with switchable rheological properties being mediated by carbon dioxide (CO 2 ). Several pH-sensitive associative amphiphilic polymers were designed by copolymerizing N , N -dimethylacrylamide (DMA) and N , N -dimethylaminoethyl methacrylate (DMAEMA), followed by hydrophobic modification. In the beginning, polymers carrying an optimal balance of hydrophilic and hydrophobic moieties exhibit shear thinning properties in an alkaline environment. After CO 2 aeration, the protonation of tertiary amine groups on the polymer backbone induces coil expansion and promotes interchain cross-linking under shear, leading to an abnormal shear thickening. The fluidic material can regain its shear thinning properties after sparging the solution with N 2 . Such a gas-controlled process is reversible and clean, which can be performed over multiple cycles. This study taps the potential of CO 2 utilization in the dynamic fluidic materials science.