Highly Elastic and Self‐Healing Composite Colloidal Gels

Abstract

Composite colloidal gels are formed by the pH-induced electrostatic assembly of silica and gelatin nanoparticles. These injectable and moldable colloidal gels are able to withstand substantial compressive and tensile loads, and exhibit a remarkable self-healing efficiency. This study provides new, critical insight into the structural and mechanical properties of composite colloidal gels and opens up new avenues for practical application of colloidal gels.

A Transparent, Highly Stretchable, Autonomous Self‐Healing Poly(dimethyl siloxane) Elastomer

“…Self‐healing materials are booming nowadays because they are able to repair mechanically induced damages, thus the lifetime of products can be prolonged . To date, numerous applications of self‐healing materials have been demonstrated in a wide spectrum of fields spanning from self‐healing surface coatings and adhesives, drug and cell delivery systems, and chemical sensors to electronics . In general, completion of the self‐healing process mainly relies on the reformation of dynamically covalent bonds, supramolecular recognitions, or filling of the encapsulated repair agents .…”

Gelatin Nanoparticle‐Injectable Platelet‐Rich Fibrin Double Network Hydrogels with Local Adaptability and Bioactivity for Enhanced Osteogenesis

“…To clearly visualize the network structure, rather dilute gel network was prepared by dispersing 1 w/v% GNPs (corresponding to volume fraction φ of ≈5%) in 5 × 10 −3 m HEPES buffer containing 0.1 w/v% fibrinogen combined with 2 U mL −1 thrombin. As shown in Figure a, 0.1 w/v% fibrinogen led to a uniformly distributed porous fibrin network after reacting with 2 U mL −1 thrombin and quenching for 1 min, whereas 1 w/v% GNPs also formed an interconnected particulate network after dispersed in neutral pH due to the cohesive interparticle forces . In comparison, we observed the formation of an interconnected network with higher porosity and thicker network strands after mixing GNPs with fibrinogen and thrombin.…”

“…GNPs have been demonstrated to form a rather elastic but also shear‐thinning and self‐healing colloidal gel due to the cohesive interactions between globally positively charged but locally amphoteric gelatin nanoparticles . This allows colloidal gels of GNPs to be injectable/printable and moldable, as well as to be easily mixed with liquid‐like materials by extrusion.…”

“…Hereby, we proposed double network (DN) hydrogels by combining autologous iPRF with amphoteric gelatin nanoparticles (GNPs) that allow a “bottom‐up” assembly of nanoparticles into an interconnected colloidal network. iPRF that is initially in liquid‐like state was combined with the noncovalently crosslinked colloidal network that is shear‐thinning and self‐healing, which led to the formation of a composite hydrogel that possessed injectability and moldability within the initial 400 s as the polymerization of fibrin network was not completed yet . The investigation of the structural and mechanical features of the composite hydrogels revealed a double network mechanism which rendered the hydrogels with toughness values and degree of deformation orders of magnitude greater than what they can achieve separately .…”

Independent Blue and Red Light Triggered Narcissistic Self‐Sorting Self‐Assembly of Colloidal Particles

“…Colloids are great models to establish concepts of self‐assembly and self‐sorting as units of advanced materials and for the assembly of synthetic cells into prototissues . Decorating colloids with DNA, proteins, and supramolecular interaction partners allows to program their self‐assembly and modify assemblies in response to external triggers such as temperature, pH, and light . Among these stimuli, photoresponsive assemblies are especially attractive since light provides noninvasive, tunable, and specific control with high spatiotemporal resolution …”