Shaokui Cao

Polymethylene-b-poly(styrene-co-2,3,4,5,6-pentafluoro styrene) copolymers: synthesis and fabrication of their porous films

New block copolymers of polymethylene-b-poly(styrene-co-2,3,4,5,6-pentafluoro styrene) (PM-b-P(St-co-PFSt)) with controlled molecular weight and narrow molecular weight distribution were synthesized via a combination of polyhomologation of ylides and ATRP copolymerization of styrene and 2,3,4,5,6-pentafluoro styrene. The molecular structure and component of PM-b-P(St-co-PFSt) block copolymers were characterized through 1H NMR, 19F NMR, GPC and elemental analysis. The porous films of these block copolymers were fabricated via the static breath-figure (BF) method. The influence of solvent, molecular weight of copolymer, relative humidity and temperature on the morphology of these block copolymer films was investigated. The porous surfaces of these films presented hydrophobic behaviour with a static water-droplet contact angle of ca. 111°.

A series of dendronized hyperbranched polymers with dendritic chromophore moieties in the periphery: convenient synthesis and large nonlinear optical effects

In this paper, by utilizing low generation nonlinear optical (NLO) dendrimers, in which one sulfonyl-based chromophore was used as an isolation chromophore for two nitro-based chromophores, as the initiator, a new series of dendronized hyperbranched polymers (DHPs), P1–P3, were prepared conveniently through one-pot atom transfer radical polymerization (ATRP) with satisfactory yields. Different from the previous NLO DHPs, of which dendritic NLO chromophores were usually linked into the interior architecture, the NLO chromophores were introduced into the periphery of P1–P3. Thanks to this special structure, all of them demonstrated large NLO effects. For P1, its NLO coefficient d33 value was tested to be 179.6 pm V−1, which, to the best of our knowledge, is among the highest values recorded so far for polymeric materials except for NLO dendrimers. In addition, the optical transparency of P1–P3 could be further improved, due to the utilization of isolation chromophores. Coupled with its high NLO coefficient and convenient synthesis, P1 could serve as a good candidate for real optical application.

Mesoporous silica-coated gold nanorods with a thermally responsive polymeric cap for near-infrared-activated drug delivery

In this work, gold nanorods (AuNRs)/mesoporous silica (SiO2) nanoparticles capped with thermal-responsive polymer were fabricated to couple the photothermal property of AuNRs and the thermal-/pH-responsive properties of polymer in a single nanovehicle. Aliphatic poly(urethane-amine) (PUA) was employed as the smart polymer to cap the mesopores of AuNRs/SiO2 nanoparticles via in situ polymerization in supercritical CO2. Thermal-/pH-responsive PUA acted as the on–off switch to control the DOX release due to the stretch and shrinkage of the PUA polymer chains at different temperatures, whereas a remote near-infrared (NIR) light was used to activate the phase change and subsequent drug release. The in vitro drug release studies indicated that Au/SiO2/PUA nanoparticles exhibited distinguished pH-, thermal-, and NIR-dependent release properties. A short time exposure to NIR irradiation could distinctly increase the local temperature of nanoparticles, and the thermal-responsive polymeric cap enabled the DOX release in a significant reversible way by simply adjusting the NIR laser intensity. The present paper provides an ideal way to fabricate NIR-responsive drug carriers by combining stimuli-responsive polymer with inorganic matrix, which is highly attractive for remote controllable drug delivery.