Qichao Zou

Resonance light scattering method for the determination of DNA with cationic methacrylate based polymer nanoparticle probes

Narrowly distributed cationic poly (methyl methacrylate-co-diacetone acrylamide) (P(MMA-DAAM)) nanoparticles were successfully prepared by microemulsion polymerization. Photon correlation spectrometer (PCS) measurement and transmission electron microscope (TEM) observation revealed that z-average particle size of P(MMA-DAAM) is ∼27.5 nm. It was found that these cationic nanoparticles interact with DNA through electrostatic interaction to form P(MMA-DAAM)-DNA complex, which significantly enhances the resonance light scattering (RLS) signal. Therefore, a novel method using this polymer nanoparticle as a new probe for the detection of DNA by RLS technique is developed in this paper. The results showed this method is very convenient, sensitive, and reproducible.

Influence of reactive POSS and DDP on thermal stability and flame retardance of UPR nanocomposites

Abstract Unsaturated polyester resins (UPR) were prepared by the melt condensation method based on adipic acid, o-phthalic anhydride, maleic anhydride and ethylene glycol in the presence of PSS-(2,3-propanediol)propoxy-heptaisobutyl substituted (PSS-POSS) or/and 9 wt% [(6-oxide-6H-dibenz(c,e)(1,2)oxaphosphorin-6-yl)methyl]butanedioic (DDP). We synthesized UPR containing DDP (DDP-UPR) and UPR containing both DDP and PSS-POSS (DDP-PSS-POSS-UPR series). The chemical structures of the modified polyesters were characterized and confirmed by Fourier transform infrared (FTIR) and 31P nuclear magnetic resonance (31P NMR). The thermal stability and flammability behaviors of UPR were evaluated by thermogravimetric analysis (TGA) and limited oxygen index (LOI) and the vertical burning test. The morphology of residual char of UPR was shown by scanning electron microscopy (SEM). The results indicate that the incorporation of PSS-POSS has little influence on the thermal stability of DDP-UPR, but enhances the flame retardance of DDP-UPR, and when the PSS-POSS content reaches 10 wt%, the DDP-PSS-POSS-UPR has better flame retardance.

Investigation of the surface properties of POSS-modified polyacrylate by inverse gas chromatography

Abstract The surface properties of poly(methyl methacryl-ate-co-n-butyl methacrylate-co-cyclopentyl methacryloxy propyl-polyhedral oligomeric silsesquioxane) (poly(MMA-co -BMA-co-POSSMA)) were studied by means of inverse gas chromatography (IGC) using 10 non-polar and polar solvents as the probes. Thermodynamic parameters of adsorption, such as the dispersive component of the surface energy, the specific interaction contribution to the free energy of adsorption and the acid/base constants of polymer surface were determined. It was found that incorporation of POSSMA into polymer resulted in increasing interactions between polymers and solvents, dispersive component of surface free energy of polymer and acidity of the surfaces of the polymers. The more the POSSMA were embedded, the larger the dispersive component of the surface free energy was, and the acidic character of the polymer surface was more obvious.