Study on glycerol doping to enhance the volatility-reducing effect of 4-n-hexadecyloxybenzaldehyde hydrazone xerogel on borneol

ZHANG Miao; HAN Bao-tong; JIA Nan; ZHANG Dong-dong; HUANG Wen-li; LI Yu-ze; XIE Yun-dong; ZHANG Hua-wei; DENG Chong; YANG Xin-jie; SONG Xiao-mei; JIANG Yi; XU Hong

doi:10.20251/j.cnki.1003-3734.2026.12.009

Abstract：Objective:To prepare a borneol-low molecular organic gelator xerogel and evaluate its effect on borneol volatility.Methods:4-Hydroxybenzaldehyde was used as the starting material,and the target low molecular organic gelator was synthesized through Williamson etherification reaction and condensation reaction.The gel was prepared by dissolving borneol and low molecular organic gelator in anhydrous ethanol and subsequently undergoing vacuum freeze-drying to remove the solvent,resulting in the borneol-low molecular organic gelator xerogel.The microscopic morphology of the xerogel was observed by scanning electron microscope(SEM).The phase transition temperature was determined by differential scanning calorimeter(DSC).The driving force for the gel formation was analyzed by Fourier transform infrared spectroscopy(FT-IR).The loss of borneol from borneol sample,borneol-low molecular organic gelator xerogel,and the borneol-low molecular organic gelator-glycerol xerogel were compared by accelerated evaporation experiment over 10 h.Results:Mixtures of borneol and low molecular organic gelator with mass ratios of 2∶1,3∶1 and 4∶1 formed a gel in anhydrous ethanol.SEM imaging revealed that the low molecular organic gelator showed a multilayered sheet-like structure.In contrast,the microstructures of the borneol-low molecular organic gelator xerogel with mass ratios of 2∶1,3∶1 and 4∶1 showed a bulk,sheet-like and reticulate structure,respectively,which proved that the assemblies were formed.Furthermore,the addition of glycerol to the borneol-low molecular organic gelator system did not significantly alter the microstructure of the resulting xerogel.DSC analysis showed that the heat absorption peaks of the borneol-low molecular organic gelator xerogel varied with the mass ratios.FT-IR analysis revealed a shift in the hydroxyl group stretching vibration to lower wavenumbers for both borneol-low molecular organic gelator xerogel and borneol-low molecular organic gelator-glycerol xerogel,confirming that hydrogen bonding was involved in the formation of gel.After the 5 h accelerated volatilization test at 50℃,the borneol loss rate was 39.34%from borneol sample,while it was 17.40%from the 4∶1 borneol-low molecular organic gelator xerogel,and 9.98%after glycerol was added.Conclusion:The borneol-low molecular organic gelator xerogel reduces the volatility of borneol,with a further reduction observed upon the addition of glycerol.