Shear-induced assembly of a transient yet highly stretchable hydrogel based on pseudopolyrotaxanes

Biocatalytic Feedback‐Controlled Non‐Newtonian Fluids

“…However, with increasing applied shear stress above σ crit ( σ =6.0 or 12.0 Pa), a plateau characterizing gelation emerged . Therefore, the observed shear thickening is shear‐gelation in nature . Note that the gelation state is in nonequilibrium; the system would eventually revert back to its initial state in the absence of agitation (Figure d).…”

Precise Synthesis of Ultra‐High‐Molecular‐Weight Fluoropolymers Enabled by Chain‐Transfer‐Agent Differentiation under Visible‐Light Irradiation

“…Ultra-high-molecular-weight (UHMW) polymers exhibit outstanding mechanical properties,g ood thermal stability, and interesting phase separation behaviors, [1] providing new opportunities for modern material discovery and engineering such as the fabrication of high-performance hydrogels, [2] photonic crystals, [3] and other materials. [1] Consequently,t he precise synthesis of UHMW polymers remains one of the enormously appealing pursuits to chemists seeking for advanced materials.Inspite of their importance,only alimited number of strategies have been reported to achieve UHMW polymers,a nd reversible-deactivation radical polymerization (RDRP) [4] is among the most frequently used methods.F or instance,t he Sumerlin [5] and An [6] groups have recently synthesized well-defined UHMW poly(acrylamide)s at high conversions for monomers of high propagating rates.H owever,f or various other polymers,t he intrinsic reactivities of different monomers impose restrictions on the attainable chain length limits.I no ther examples,U HMWs were achieved through the compromise of incomplete monomer conversion, and/or judicious selection of reaction conditions (such as high pressure, [7] catalytic systems, [8] and heterogenous conditions [9] ).…”

Biocatalytic Feedback‐Controlled Non‐Newtonian Fluids

“…[4] The role of charges in these atypical associative polyelectrolytes is still elusive, except that a small amount of charges is believed to be indispensable. Nevertheless, the underlying mechanism must involve supramolecular interactions, rather than interactions between colloidal particles, enabling a rational design of stable, sophisticated, and intelligent fluidic systems based on polymer engineering.Although physical energy (for example, in the form of shear force or light) has commonly been used as the energy source in artificial smart materials, [5] nature predominantly harnesses chemical and biochemical energy as a means for the temporal control of a functionality. The development of dissipative systems fueled with chemical energy sources is challenging as well as intriguing, as it may bring us closer to using synthetic systems to mimic the marvelous properties of living systems or even creating novel responsive systems unfound in nature.…”

“…Although physical energy (for example, in the form of shear force or light) has commonly been used as the energy source in artificial smart materials, [5] nature predominantly harnesses chemical and biochemical energy as a means for the temporal control of a functionality. The development of dissipative systems fueled with chemical energy sources is challenging as well as intriguing, as it may bring us closer to using synthetic systems to mimic the marvelous properties of living systems or even creating novel responsive systems unfound in nature.…”