Li-Ping Wang,Yu-Chao Li,Li-Feng Chen,Chao-Lei Ban,Guang Li,Jun-Jie Ni
Poly(styrene)- b -poly(N-isopropylacrylamide) (PS- b -PNIPAM) amphiphilic diblock copolymers were synthesized via reverse iodine transfer polymerization (RITP) firstly. And then the honeycomb structured porous films were fabricated by drop the amphiphilic diblock copolymer solutions on glass substrates . The porous films were characterized using field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM), respectively. The results showed that the regular honeycomb patterned porous film was achieved successfully by employing the block copolymer with a significantly larger polystyrene block proportion into the solution and the pore diameter of the film decreases obviously with the polymer concentration increased. The effects of airflow speed and Ag particles on porous films are also discussed in this study.
Yan Wang,Jie Zhang,Jianlei Lu,Nan Hai,Jiawei Zhang
In this study, we developed a poly(styrene- b - N -isopropyl acrylamide) (PS- b -PNIPAm) block copolymer-incorporated hydrogel with cooling/water dual-responsive shape recovery performance. Three kinds of PS- b -PNIPAm block copolymers with different chain lengths of PNIPAm were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization, and the block copolymers could self-assemble into micelles with PNIPAm as the outer layer in water. Hydrogels were then prepared by introducing the micelles formed by the block copolymers into the polyacrylamide (PAM) network. The collapse of PNIPAm chains could be promoted by both temperature and salt, which acted as temporary crosslinks to stabilize temporary shapes, enabling cooling- and water-stimulated shape recovery. Moreover, fluorescent information could be encoded on the surface of the hydrogel and encrypted by the shape changes of the hydrogel during the shape fixing process, with the information revealed under UV irradiation after the shape recovery process, achieving information security. This approach could accelerate the evolution of shape memory hydrogels and broaden their applications across diverse fields.
危险品化学品经营许可证（带存储）