Chemically Fueled Volume Phase Transition of Polyacid Microgels

Abstract

Microgels are soft colloids that showr esponsive behavior and are easy to functionalizef or applications.T hey are considered key components for future smart colloidal material systems.H owever,s of ar microgel systems have almost exclusively been studied in classical responsive switching settings using external triggers,w hile internally organized, autonomous control mechanisms as found in supramolecular chemistry and DNAn anotechnology relying on fuel-driven out-of-equilibrium concepts have not been implemented into microgel systems.H ere,w ei ntroduce chemically fueled transient volume phase transitions (VPTs) for poly(methacrylic acid) (PMAA) microgels,w here the collapsed hydrophobic state can be programmed using the fuel concentration in ac yclic reaction network. We discuss details of the system behavior as af unction of pH and fuel amount, unravel kinetically trapped regions and showcase transient encapsulation and time-programmed release as afirst application.

Fuel‐Driven and Enzyme‐Regulated Redox‐Responsive Supramolecular Hydrogels

“…In contrast, a single‐substrate‐promoted self‐regulation requires a more unique and delicate programming to balance the kinetics of activating and deactivating reactions while keeping the waste impurities to a minimum. [ 9d , 11a , 15 ]…”

“…We note that although the extra addition of fuel provides more versatile control and modulation of the transition out‐of‐equilibrium, the amount of residual waste inside the system after several cycles can lead to a lack of cyclability of the CRN and/or the material. In contrast, a single‐substrate‐promoted self‐regulation requires a more unique and delicate programming to balance the kinetics of activating and deactivating reactions while keeping the waste impurities to a minimum [9d, 11a, 15] …”

Substituent Effects on Transient, Carbodiimide-Induced Geometry Changes in Diphenic Acids

“…Abiotic systems that are driven out-of-equilibrium by chemicals have recently received a great deal of attention. ,− Carbodiimides, typically EDC (( N -(3-(dimethylamino)-propyl)- N ′-ethylcarbodiimide hydrochloride), stand out as versatile fuels. They have been used in recent reports by Boekhoven, − us, − Das, , and several other research groups − to generate nonequilibrium behavior. The associated chemistry is quite simple: carbodiimides react with aqueous carboxylic acids to generate carboxylic anhydrides that then undergo hydrolysis to regenerate the parent carboxylic acids.…”

Brennstoffbetriebene und enzymregulierte redoxresponsive supramolekulare Hydrogele

“…Erwähnenswert ist, dass die externe Zugabe von Treibstoff für eine hohe Steuerbarkeit des Nichtgleichgewichts sorgt, die Akkumulation von Abfallprodukten allerdings die Zyklisierbarkeit des CRN und/oder des Materials einschränken kann. Dagegen benötigt eine interne Selbstregulierung durch einzelne Substrate ein Vielfaches an Feinabstimmung, um die Kinetik von Aktivierung und Desaktivierung abzustimmen, wobei Verunreinigungen auf ein Minimum reduziert werden können [9d, 11a, 15] …”