The insets are their contact angle images, respectively. To investigate the enhancement mechanism, the calculated results of the surface tension between the samples and water are shown in the insets of Figure 1. These contact angle values provide an objective explanation on the wettability of the samples which is relative to the adhesion behavior of the platelets. It is clear that the contact angle of water and surface tension of NH2/MWCNTs are relatively low, indicating that NH2 + implantation induces an increase in the hydrophilicity of MWCNTs. In order to analyze the changes of the functional groups caused by the NH2 + implantation, FTIR
www.selleckchem.com/products/ag-881.html analysis is peformed. Figure 2a shows the transmission Histone Methyltransferase inhibitor spectra of the pristine MWCNTs and NH2/MWCNTs with fluencies of 5 × 1014 and 1 × 1016 ions/cm2. Among many peaks, the peak at 1,200.11 cm−1 corresponds to C-C stretching vibration, while the peak at 836.69 cm−1 corresponds to C-O stretching vibration.
NH2 + implantation produces new peaks at 1,319.56 cm−1 corresponding to C-NO stretching vibration and at C=N stretching vibration at 1,601.69 cm−1. This result proves the decomposition of some chemical bonds and formation of new N-containing functional groups. Figure 2 Transmission spectra of MWCNTs and NH 2 /MWCNTs. (a) SB525334 mw FTIR spectra of pristine MWCNTs and NH2/MWCNTs with 5 × 1014 and 1 × 1016 ions/cm2. C1s XPS spectra obtained from (b) pristine MWCNTs, (c) NH2/MWCNTs with 5 × 1014 ions/cm2, and (d) NH2/MWCNTs with 1 × 1016 ions/cm2. High-resolution C1s peaks of the samples presented in Figure 2b,c,d show more detailed chemical modification after NH2 + implantation. Compared with the corresponding peak obtained from the pristine sample, the high-resolution C1s peak of NH2/MWCNTs appears as a new C=N bond, and meanwhile, the C-C bond declines, indicating that some pristine C-C bonds are broken by ion implantation to reconstruct
new bonds with N. What is more, the spectrum of the implanted sample with fluency of 1 × 1016 ions/cm2 displays higher intensity of C=N bond at 285.5 eV as compared with the spectrum of the implanted sample with 5 × 1014 ions/cm2, which proves that higher content of N element can be obtained with Vildagliptin the higher implanted fluency. Platelet adhesion test is one of the simple and preliminary approaches to evaluate the hemocompatibility of biomaterials. Good surface antithrombogenicity is indicated by a small quantity of the platelets adhered on the surface, less activation, and morphological change. Figure 3a gives the platelet adhesion rates of different materials including the blank and the negative and positive control groups. It is clear that pristine MWCNTs and NH2/MWCNTs have lower platelet adhesion rate than the positive control group, interestingly that NH2/MWCNTs with 1 × 1016 ions/cm2 reveal the lowest platelet adhesion rate among all groups.