pH controlled green luminescent carbon dots derived from benzoxazine monomers for the fluorescence turn-on and turn-off detection

Compressible, Flame-Resistant and Thermally Insulating Fiber-Reinforced Polybenzoxazine Aerogel Composites

“…Thirdly, the gel filled the pores among the fibers, and adhered to the surface of the fibers to obtain stable aerogel composites. The FT-IR spectra of the MDA monomer and PBO aerogel are shown in Figure 2; all of the characteristic absorption peaks are basically consistent with those of PBO aerogels reported in our previous study [23], wherein the peaks at 3415, 3010 and 1226 cm −1 are attributed to the symmetric stretching of O-H, anti-symmetric stretching vibrations for C-H [22,26], and Ph−O−C stretches [27], respectively, in both MDA monomer and PBO aerogels. The 1500-1700 cm −1 region is dominated by C=C (benzene ring), and is difficult to interpret.…”

Thermal Insulation Characteristics of Polybenzoxazine Aerogels

“…Figure shows the FT‐IR spectra of the PBO aerogels. All the specimens showed a broad absorbance peak at 3400 cm −1 , which is attributed to the stretching of the phenolic OH groups . The peak at 2960 cm −1 is attributed to the symmetric stretching of CH 3, whereas the peaks located at 1500–1700, 1265, 1103, and 827 cm −1 belong to CC (benzene ring), PhOC stretches and the out‐of‐plane bending vibration of CH, respectively .…”

“…All the specimens showed a broad absorbance peak at 3400 cm −1 , which is attributed to the stretching of the phenolic OH groups. [28] The peak at 2960 cm −1 is attributed to the symmetric stretching of CH 3, [24,25] whereas the peaks located at 1500-1700, 1265, 1103, and 827 cm −1 belong to CC (benzene ring), PhOC stretches and the out-of-plane bending vibration of CH, respectively. [15] Compared with the spectra of the BPA monomer (Figure 1), the characteristic absorption peak of 937 cm −1 disappeared or became weak in the PBO aerogels, indicating that the BPA monomers had been polymerized ringopened to form PBO.…”

Room Temperature Oxalic Acid‐Catalyzed, Ambient Pressure Dried, and Cost‐Effective Synthesis of Polybenzoxazine Aerogels for Thermal Insulation

“…Infrared FT-IR spectra of the PH-mda monomer and asprepared PBZ aerogels are shown in Figure 3, and peaks marked explicitly are discussed. Both PH-mda monomer and PBZ aerogels show broad O─H stretches at 3420 cm À1 , [37,38] whereas the intensity of the absorption peak in PBZ aerogels is much stronger than that of the PH-mda monomer, indicating that phenolic O─H is formed due to the ring opening of the monomer. In addition, the strong asymmetric/symmetric Ph─O─C stretches (1228 and 1031 cm À1 )and the cyclic acetal stretches (935 cm À1 ) of PH-mda monomer have been weakened remarkably or disappeared in PBZ aerogels, [39][40][41] as well as the peak of 1442 cm À1 appeared in PBZ, which is attributed to the in-plane carboncarbon stretching of the tetrasubstituted benzene ring, further indicating that PH-mda monomer has been ring-opening polymerized to form PBZ.…”