Fig. 1. SEM images of the composite microspheres of ZnS/(PNIPAM-co-MAA) (a, c) and images of their enlarged surface structures (b, d). The formulations for the preparation of the three ZnS-PNIPAM-MAA composite microspheres are different. (a, b) MAA/NIPAM 10% (w/w), 1.5 mL of aqueous Zn (Ac)2 solution (0.3 mol/L) and (c, d) MAA/NIPAM 20% (w/w), 1.5 mL of aqueous Zn(Ac)2 solution (0.3 mol/L). The products range from 60 to 70 mm in diameter, and exhibit complex but periodically patterned surface structures. It can be seen that the surface morphologies of the composite microspheres not only depend on the composition of the template but also on the ratio of the metal sulfide to the template.

Fig. 2. SEM images of the composite microspheres of CdS/PNIPAM-MAA (a, b, c, e) and images of their enlarged surface structures (d, f). The compositions of the template used for the preparation of the composite microspheres are different. (a, b,c,d) MAA/NIPAM 10% (w/w) and (e, f) MAA/NIPAM 20% (w/w), 1.5 mL of aqueous Cd(Ac)2 solution (0.3 mol/L). It can be observed that the surface structures of the CdS-PNIPAM -MAA composite microspheres are unique and full of wrinkles (which look like they have been folded artificially). Variation in the content of MAA in the microgels only results in a difference in the density of the wrinkles. The composite microspheres prepared in this method may adopt “core-shell”-like structures (b).
Langmuir 2004, 20, 263-265
（2）Preparation of metal sulfide-polymer composite microspheres with patterned surface structures
Yu Fang*, Chaoliang Bai and Ying Zhang

Fig. 1. SEM images of the composite microspheres. (a) CuS-NIPAM, (c) CuS-PNIPAM-MAA, (b) and (d) high magnification images of a and c, respectively. Precipitation reaction was lasted for 25 min. The products range from 50 to 65 mm in size, and have complex, but regular surface morphologies.The surface of the CuS-PNIPAM composite microspheres is unique and full of wrinkles, the surface structure of the CuS-PNIPAM-MAA microspheres looks like waste cotton yarns. The difference in the surface structures of the two composites may be a result of utilization of different templates.

Fig. 2 SEM images of Ag2S-PNIPAM and Ag2S-PNIPAM-MAA composite microspheres (a, c) and high magnification images of part of the surfaces of the micro-spheres (b, d). The precipitations were lasted for 25 min. It can be seen that the surface structure of Ag2S-PNIPAM is more or less similar to that of CuS-PNIPAM. The surface structure of Ag2S-PNIPAM-MAA is very different from that of CuS-PNIPAM-MAA, and looks like closely arranged hovenia dulcises.

ChemComm
(3) Preparation of spherical nano-structured poly(methacrylic acid)/PbS composites by a microgel template method

Ying Zhang, Yu Fang*, Shan Wang, Shuyu Lin
Fig. 1. ?An optical micrograph of the water swollen PMAA microgels produced by inverse suspension polymerization with xylene as continuous phase (original magnification ′100). It can be seen that the microgels in water swelling state are spherical and have smooth surface structure. They are nearly mono-disperse, and the average diameter is about 300 mm.

Fig. 2. Scanning electron micrographs of the spherical PMAA/PbS composites prepared by microgel template method with xylene as a continuous phase (stirring speed 410 rpm). (a) mono-disperse (original magnification ′200); (b) fishnet-like surface structure (original magnification ′1200); (c) core-shell structure (original magnification ′1100). It is demonstrated that the composites are spherical and nearly mono-disperse in size distribution. Unlike the template in swollen state, the surface of the spherical composite is far from smooth, and has a fishnet-like structure. As that expected, the inner structure of the spherical composite is different from that of the outer part.

Fig. 3. SEM micrographs of the spherical PMAA/PbS composites prepared via microgel template method with cyclohexane as a continuous phase (stirring speed 410 rpm). (a) size distribution and morphology (original magnification′500); (b) surface structure (original magnification ′1500). Compared with that prepared from the system with xylene as a continuous phase, the surface of the micro-spheres prepared from the later system looks much smoother and denser, indicating that the nature of the continuous phase has a significant effect upon the structure of the spherical PMAA/PbS composites.

Fig. 4. SEM micrographs of the spherical PMAA/PbS composites prepared via microgel template method with cyclohexane as a continuous phase (stirring speed 590 rpm). (a) Size distribution and morphology (original magnification ′100); (b) surface structure (original magnification ′2500); (c) enlarged structure of the surface of the spheres (original magnification ′10000). The structure of the surface of the micro-spheres looks much loser than that prepared in the same system but stirring speed is lower.

Fig. 5. XRD patterns of (a) PMAA microgels; (b) PMAA/PbS composites, and (c) PMAA/PbS composites annealed at 200 °C for 2 h. In contrast, the profile of the organic-inorganic composites contains a number of sharp peaks shows that some crystalline materials are present within the samples.

Fig. 6. ?Fluorescence excitation and emission spectra of the PMAA/PbS composites (lex = 390 nm; lem = 573 nm). The profile and position of the fluorescence emission and excitation of the composite are in accordance with those of PbS, indicating that PbS is the dominant component of the precipitation.
J.Colloid and Interface Sci.(in press)
最新研究动态

Fig. 1. SEM images of the composite microspheres of CuS-PNIPAM-AA (a, c, e) and images of their enlarged surface structures (b, d, f) prepared by microgel template method. The compositions of the template used for the preparation are the same (AA/NIPAM: 10% (w/w) and the contents of aqueous Cu (Ac)2 solution are 0.1 mol/L (a), 0.2 mol/L (c), 0.3 mol/L (e), respectively.

Fig.2. SEM images of the composite microspheres of CuS/PNIPAM-AA (a, c, e) and images of their enlarged surface structures (b, d, f) prepared by microgel template method. Precipitation reaction was lasted for 30 min. The compositions of the template used for the preparation are different, AA/NIPAM (a: 5%; c: 10%; e: 20%, w/w) respectively, and 1mL of aqueous Cu (Ac)2 (0.3mol/L) used are same.