Uniform cadmium sulfide (CdS) nanospheres were successfully prepared in the presence of the anionic surfactant sodium dodecylsulfate (SDS) at an appropriate concentration and relatively low temperature. Zeta potential data were collected for the three kinds of CdS particles to verify the existence of the Cd2+counterion on the CdS surface and Charge reversal; this was crucial for the explanation of how the anionic SDS surfactant molecules adsorbed on the negatively charged surface. Moreover, we confirmed that SDS had coated the surface of CdS nanospheres using infrared spectroscopy, and thermogravimetric analysis. An counterion assisted mechanism accounting for synthesis of CdS nanospheres could be widely used in the synthesis of nanomaterials if there is specific adsorption of the counterion. The CdS nanospheres showed good performance for the rapid adsorption of methylene blue. 相似文献
Summary: Applying a dialysis process, new nanoparticles based on well‐defined dextran esters of furan‐2‐carboxylic‐ and pyroglutamic acids were prepared, which can undergo cross‐linking by UV irradiation. The highly functionalized products (total DS > 2) avoid the collapse of nanoparticles due to the prevention of hydrogen bond formation. The major fraction of the dextran ester nanospheres exhibits narrow size distribution down to 250 nm as mean diameter investigated by SEM.
SEM images of dextran furoate pyroglutamate nanospheres. 相似文献
Tri-layer CdS/SiO2/polymer hybrid nanospheres were synthesized by distillation precipitation polymerization of either ethyleneglycol dimethacrylate（EGDMA） or EGDMA together with comonomers having different functional groups, such as methacrylic acid,4-vinylpyridine and 2-hydroxyethylmethacrylate,in the presence of 3-（methacryloxy）propyl trimefhoxysilane（MPS）-modified CdS/SiO2 nanoparticles as seeds in acetonitrile with 2,2’-azobisisobutyronitrile（AIBN） as initiator.In this approach,MPS-modified inorganic seeds were prepared by the modification of CdS/SiO2 nanoparticles via the self-condensation reaction between the hydroxyl groups of sinaols,in which the CdS/SiO-2 nanoparticles were afforded by a reverse microemulsion technique for the synthesis of CdS core nanoparticles with the subsequent coating of silica layer. The polymer shell-layers encapsulated over the MPS-modified CdS/SiO2 inorganic seeds via the efficient capture of the monomers and oligomers from the solution with the aid of the vinyl groups incorporated by the MPS modification,in which the polymer shell-thickness and functional groups including carboxyl,pyridyl and hydroxyl,were facilely controlled by the feed of EGDMA as well as the types of comonomers used for the polymerization.These nanospheres were characterized by transmission electron microscopy（TEM）,Fourier-transform infrared spectroscopy（FT-IR）,thermogravimetric analysis （TGA）,fluorescence spectroscopy and zeta potential. 相似文献
In this study, we report the synthesis of monodispersive solid and hollow CdS spheres with structure‐dependent photocatalytic abilities for dye photodegradation. The monodispersive CdS nanospheres were constructed with the assistance of the soulcarboxymthyi chitosan biopolymer under hydrothermal conditions. The solid CdS spheres were corroded by ammonia to form hollow CdS nanospheres through a dissolution–reprecipitation mechanism. Their visible‐light photocatalytic activities were investigated, and the results show that both the solid and the hollow CdS spheres have visible‐light photocatalytic abilities for the photodegradation of dyes. The photocatalytic properties of the CdS spheres were demonstrated to be structure dependent. Although the nanoparticles comprising the hollow spheres have larger sizes than those comprising the solid spheres, the hollow CdS spheres have better photocatalytic performances than the solid CdS spheres, which can be attributed to the special hollow structure. 相似文献
Core–shell silica (SiO2) coated CdS nanorods (NR) and nanospheres (NS) were prepared (SiO2@CdS) by deposition of a Si–O–Si amorphous layer over the CdS surface through the hydrolysis of 3-mercaptopropyltrimethoxysilane and tetraethylorthosilicate. Nanoporous SiO2 matrix (NPSM), hollow SiO2 nanotubes (HSNT) and nanospheres (HSNS) useful for efficient adsorption and catalytic processes were prepared by chemical dissolution of CdS–NS (size: 9–10 nm) and CdS–NR (length: 116–128 nm and width: 6–11 nm) template from SiO2@CdS with 2 M HNO3. These SiO2 nanostructures were characterized by optical absorption, TEM, EDX, SAED and BET surface area analysis. TEM images revealed the fabrication of slightly distorted HSNS (size: 9–12 nm) and closed HSNT (length: 30–45 nm and diameter: 9–14 nm) of shorter dimensions than the CdS–NR template used. The BET surface area (112–134 m2 g?1) of NPSM and HSNS is found to be larger than the surface area (29–51 m2 g?1) of SiO2@CdS composites indicating hollow SiO2 morphology. Silica coated Au (SiO2@Au) composites formed by CdS dissolution from Au (2 wt%) deposited CdS–NR core-encapsulated into SiO2 shell (SiO2@Au–CdS–NR) exhibited a surface plasmon band at 550 nm and displayed high catalytic activity for 4-nitrophenol reduction by Au nanoparticle. 相似文献
Fluorescent polystyrene(PS)/porphyrin(TPPA) composite nanospheres were successfully fabricated by electrospinning. The SEM images clearly show that owing to adding TPPA in PS, the averaged diameter of the composite nanospheres became smaller, from 1500 to 580 nm. Fourier-transform infrared(FTIR) spectra determined the chemical composition of the resulting PS/TPPA composite nanospheres. The photoluminescent(PL) spectral analysis indicates that the peak position of the composite nanospheres in either solid st... 相似文献
