Preparing a pseudo-solid by the reinforcement of a polydentate thioether using silver nanoparticles

Preparation of Poly(thiol-urethane) Covalent Adaptable Networks Based on Multiple-Types Dynamic Motifs

To solve the issue of polymeric materials recycling, developing intrinsic self-healing materials containing dynamic bonds has attracted many researchers' highly concerning. However, the tradeoff between their mechanical strength and stretchability always does not avoid. Herein, to surmount the above tradeoff, metal-ligand (Cu²⁺ -S) interactions are introduced into the cross-linking polythiourethane covalent adaptable networks (PTU CANs) with three kinds of dynamic motifs (thiourethane, disulfide, and hydrogen bonds). When the molar ratio of Cu²⁺ to S is 6.37%, the break strength (9.41 ± 0.34 MPa) and Young's modulus (26.02 ± 0.55 MPa) of the metal-ligand coordination complex PTU (Cu²⁺ -PTU-3) dramatically increase, whereas the peak strain almost does not decline (454.44 ± 3.95%). To conduct the repairing, Cu²⁺ -PTU-3 is further confirmed excellent repairing capability. Therefore, these new PTU CANs have significant potential for the new self-healing materials.

A comparative study of stability, antioxidant, DNA cleavage and antibacterial activities of green and chemically synthesized silver nanoparticles

Silver nanoparticles have a wide range of research, industrial and biomedical applications that make it essential to develop a low cost and eco-friendly approach with scaling up potential. Green synthesis of nanoparticles through bio-reactions leads to a reduction of silver ions to particles could be an acceptable selection using no additional reducing chemicals. Moreover, the simplicity of scale-up processes of the method makes it more efficient than chemical and physical synthesis methods. In this study, Datura stramonium leaf extract and sodium citrate were used as biological and chemical reducing and stabilizing agents to make silver nanoparticles. The main goal is to comprise properties and evaluate antibacterial activity of nanoparticles synthesized through two approaches. Size and morphology compared between the two types of the synthesized nanoparticle by UV-Visible spectroscopy, DLS, AFM, TEM and their antibacterial effects were evaluated through growth inhibition MIC and MBC methods. The results showed narrow size range, spherical shape, high anti-oxidant, antibacterial and DNA cleavage activities of green synthesized silver nanoparticles comparing to less average size, wider range of nanoparticle size, no anti-oxidant activity and less antibacterial and DNA cleavage activities of chemically synthesized nanoparticles. The green synthesized silver nanoparticles had more desirable characteristics and biological activities compared to chemically synthesized nanoparticles. For instance, the green nanoparticles showed narrow size range, spherical shape, high anti-oxidant, antibacterial and DNA cleavage activities versus the chemically synthesized which had less average size, higher range of nanoparticles size, no anti-oxidant activity and less antibacterial and DNA cleavage activities.

Multifunctional polymers built on copper–thioether coordination

Copper–thioether coordinated block polymers were successfully constructed to form mechanically tough materials with a color response towards hydrochloric acid and hydrogen peroxide.