New immobilized Schiff bases

Graphene Oxide-Silica Composite Fillers into the Experimental Dental Adhesives for Potential Therapy

“…[15] Several minor bands at around 2800 to 3000 cm -1 were also detected in the spectra of APTES@SiO2, which were attributed to the N-H stretching vibration. [16] As GO has a large amount of OH groups, the broad band around 3350 cm -1 of GO@SiO2 was higher than that of APTES@SiO2. In addition, Raman spectroscopy, which was utilized as a powerful tool for the characterization of graphene and its derivatives, was employed to further identify the GO@SiO2.…”

“…The structure of GO@SiO2 was characterized by FTIR and Raman. As shown in Figure 2a, the main peaks of SiO2 spectra curve at 797, 1050, 1626 cm -1 and the broad band around 3350 cm −1 were identified as symmetric vibrations of Si-O-Si, asymmetric vibrations of Si-O-Si, bending vibration of O-H and stretching vibration of OH, [14][15][16] respectively. After surface modification by APTES, the broad band at 3350 cm -1 became weak, which indicated the decrease of hydroxyl on SiO2 surface.…”

Degree of Conversion, Bond Strength and Biocompatibility of the APTES@SiO2 Strengthened Experimental Dental Adhesive

“…[25] Several minor bands at around 2800 to 3000 cm -1 were also detected in the spectra of APTES@SiO 2 , which were attributed to the N -H stretching vibration. [25,26] Therefore, this result illustrated that APETS was successfully grafted onto the surface of SiO 2 .…”

“…The FTIR spectra of SiO 2 before and after APTES modification were shown in Figure 3c. The characteristic absorption peaks of SiO 2 spectra curve at 786, 1046, and 1629 cm -1 and the broad band around 3262 cm -1 were identified as symmetric vibrations of Si-O-Si, asymmetric vibrations of Si-O-Si, bending vibration of O-H and stretching vibration of OH, [24][25][26] respectively. After surface modification by APTES, the broad band at 3262 cm -1 became weak, which indicated the decrease of hydroxyl on SiO 2 surface.…”

Mononuclear Complexes Based on Pyrimidine Ring Azo Schiff‐Base Ligand: Synthesis, Characterization, Antioxidant, Antibacterial, and Thermal Investigations

“…The 1 H NMR spectrum of the azo Schiff base ligand exhibits a singlet signal in the 8.78 ppm, which is attributed to the azomethine group (–CH=N–) proton 39. The singlet at 9.56 ppm (d) was due to pyrimidine ring (C–H) proton in the spectrum of the ligand 42. The spectrum of the ligand showed other signals at 8.45 (d, 1 H, Ar–H, J = 2.4 Hz), 8.07 (dd, 1 H, Ar–H, J = 2.4 Hz and 8.8 Hz), 7.87 ppm (t, 4 H, Ar–H, J = 6.4 Hz), 7.62–7.31 ppm (m, 11 H, Ar–H), and 7.22 ppm (d, 1 H, Ar–H, J = 8.8 Hz) for aromatic protons.…”