97 × 10−19 2.90 × 10−18 1.70 × 10−18 3.65 × 10−18 2.90 × 10−18 N a FePt Total Fe + Pt atoms per particle – 65,453 6,573 5,611 2,391 6,964 4,076 8,749 6,964 N p Fe Iron atoms per particle – 38289.9 3339.1 3540.5 1190.9 3913.8 2095.3 5048.1 3558.6 learn more N p Pt Platinum atoms per particle – 27162.9 3234.0 2070.4 1200.5 3050.3 1981.1 3700.8 3405.4 W L Weight percent ligand wt.% 27.2 50.0 52.9 42.5 43.2 33.7 34.4 41.7 W FePt Weight percent naked FePt wt.% 72.8 50.0 47.1 57.5 56.8
66.3 65.6 58.3 N p L Number of ligands per mg SIPPs Ligand/mg SIPP 6.08 × 1017 1.12 × 1018 1.32 × 1018 1.06 × 1018 1.22 × 1018 9.52 × 1017 1.12 × 1018 1.36 × 1018 I FeOx Intensity of iron oxide peak (TGA) Deriv. wt.% °C 0.091 0.068 0.033 0.047 0.054 0.019 0.000 0.000 We next examined whether the fatty amine ligands were bound to the SIPP alloy this website cores, using FTIR. Figure 2 shows the
spectrograms of each of the fatty amines alone, as well as the particles synthesized using the various ligands with either a 30- or 60-min reflux time. The peaks at approximately 900 and approximately 3,350 to 3,500 cm−1 corresponding to the amine stretching and wagging are clearly visible in each of the spectra of the ligands alone. In selleck contrast, these amine peaks in the FT-IR spectra disappear in all spectra of SIPPs. This suggests that the fatty amines were all bound to the surface of the SIPP alloy surface through the amine groups, regardless of which ligand was used or the amount of time the reaction was allowed to reflux. It has also been suggested [13] that and Fe-O stretch can be observed at approximately 580 to 600 cm−1. We noticed a broad peak in all of the SIPP spectra, except that for the DDA-SIPPs, Erastin concentration suggesting that some iron oxide contamination may also be present in the samples. Figure 2 FTIR spectrographs of SIPPs and fatty amines. FTIR spectrographs of SIPPs synthesized using ODA (top left), HDA (top right), TDA (bottom left), and DDA (bottom right). Please refer to the text for more details. In addition to determining the size of the SIPPs and whether the ligands were bound to the surface, we also wanted to determine the composition of the SIPPs. We used TGA and DSC to determine the weight percent of ligand
versus naked iron-platinum alloy. We also used the DSC capabilities in an attempt to characterize the amount, if any, of iron oxide contamination in the samples. Figure 3 shows the thermograms for each of the particles and fatty amines. The weight percent values of the ligands and naked iron-platinum are listed in Table 1 for each of the nanoparticles synthesized. In general, slightly more naked iron-platinum was found in the particles synthesized with the shorter-chained fatty amines, TDA, and DDA.