Shape memory performances of homogeneous poly(L-lactide-co-ε-caprolactone)/polytrimethylene carbonate-grafted functionalized graphene oxide nanocomposites

A shape-memory poly(ε-caprolactone) hybridized TiO2/poly(l-lactide) composite with antibacterial properties

Organic-inorganic composites as an efficient strategy to upgrade the structural and functional properties of synthetic polymers are attracting extensive attentions. However, there are few studies on the shape memory (SM) behavior of organic-inorganic composites. In the work, poly(ε-caprolactone) hybridized TiO2 nanomaterial (PCL-TiO2) is made as the switching phase and integrated into poly (l-lactide) (PLLA) to construct an SM composite. PCL-TiO2/PLLA shows "sea-island" structure and better interfacial adhesion than PCL/PLLA, which facilitates the transmission of elastic power between the switching phase and the fixing phase. PCL-TiO2 as switching phase exhibits lower enthalpy at 57 °C than PCL, and PCL-TiO2 also acts as "heat dispersion pump station", which builds a dynamically responsive system and initiates shape change. The shape fixing and recovery ratio of PCL-TiO2/PLLA are 93.9 % and 94.4 %, respectively, and go back to the original shape within 15 s at 57 °C. At the same time, PCL-TiO2 endows SMP with good antibacterial properties. Then this work provides a well-placed way for developing SM materials with structure-function integration.

Ultra-stretchable and biodegradable elastomers for soft, transient electronics

As rubber-like elastomers have led to scientific breakthroughs in soft, stretchable characteristics-based wearable, implantable electronic devices or relevant research fields, developments of degradable elastomers with comparable mechanical properties could bring similar technological innovations in transient, bioresorbable electronics or expansion into unexplored areas. Here, we introduce ultra-stretchable, biodegradable elastomers capable of stretching up to ~1600% with outstanding properties in toughness, tear-tolerance, and storage stability, all of which are validated by comprehensive mechanical and biochemical studies. The facile formation of thin films enables the integration of almost any type of electronic device with tunable, suitable adhesive strengths. Conductive elastomers tolerant/sensitive to mechanical deformations highlight possibilities for versatile monitoring/sensing components, particularly the strain-tolerant composites retain high levels of conductivities even under tensile strains of ~550%. Demonstrations of soft electronic grippers and transient, suture-free cardiac jackets could be the cornerstone for sophisticated, multifunctional biodegradable electronics in the fields of soft robots and biomedical implants.