Typically, 0.25 mmol of gold acetate, 0.25 mmol of zinc acetylacetonate,

0.1358 mmol of PEO-PPO-PEO, and 2.5 mmol of 1,2-hexadecanediol were mingled in 10 ml octyl ether in a 250-ml flask under vigorous stirring. The reaction mixture was first slowly heated to 125°C within 2 h and homogenized at this temperature for 1 h under vigorous stirring, then rapidly heated to 280°C within 15 min and refluxed at the temperature for 1 h. After cooling down to room temperature, ethanol was added to the reacted solution to precipitate the PEO-PPO-PEO-laced ZnO-Au nanoparticles by centrifugation. The precipitated product was washed with ethanol/hexane (2:1) several times. The resultant nanoparticles prepared in such a process can be re-dispersed in hexane, ethanol, and distilled water directly, without a secondary surface modification which selleck inhibitor is usually required [17]. For comparison, Au and ZnO selleck nanoparticles were prepared similarly using only gold acetate or zinc acetylacetonate as the precursor. The morphology of the ZnO-Au nanoparticles was analyzed by transmission electron microscopy (TEM, JEM-100CX), whereas the structure

was characterized by X-ray diffractometry (XRD, X’Pert Pro, PANalytical B.V., Almelo, The Netherlands; λ = 1.54056 Å) using Cu Kα radiation. An Avatar 360 Fourier transform infrared spectroscopy (FTIR) spectrometer (Nicolet Company, Madison, WI, USA) was applied to perform the Fourier transform infrared spectroscopy investigation. In the FTIR studies, the washed ZnO-Au nanoparticles and the pure PEO-PPO-PEO polymer employed in the preparation were

crushed with a pestle in an agate mortar, the VX-680 individually crushed material was mixed with potassium bromide (IR spectroscopy grade) (Merck, Darmstadt, Germany) in about 1:100 proportion. The mixture was then compressed into a 2-mm semitransparent disk by applying a force of 10 t for 2 min. The FTIR spectra were recorded at the wavelength range of 400 to 4,000 cm-1. Moreover, the optical properties of the ZnO-Au nanoparticles separately dispersed in hexane, ethanol, and water, together with the Au and ZnO nanoparticles in hexane, were characterized by an UV-visible spectrophotometer (UV-vis near Florfenicol IR spectrophotometer, Hitachi U4100; Hitachi, Shanghai, China) and a photoluminescence (PL) spectrophotometer (Hitachi F7000, Japan). Results and discussion The morphology and particle size of the prepared ZnO-Au hybrid nanoparticles are shown in Figure 1a. Apparently, the nanoparticles are highly crystalline, virtually uniform, and spherical in shape. The particle size histogram from the size counting of the nanoparticles acquired from a series of TEM images shows a tight size distribution which is described quite satisfactorily by a Gaussian function and gives an average particle size of approximately 9.9 nm in diameter and a standard deviation of 1.1 nm.