石榴皮中纤维素纳米晶体的提取与表征

Extraction and characterization of cellulose nanocrystals from pomegranate peel

为提高石榴皮的附加值,采用碱处理、次氯酸钠漂白法制备了石榴皮纤维素,通过酸水解成功得到石榴皮纤维素纳米晶体(pomegranate peel cellulose nanocrystals,PCNC)。并对PCNC进行粒径和稳定性表征,同时采用扫描电子显微镜、原子力显微镜、傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)、X射线衍射(X-ray diffraction,XRD)、差示扫描量热分析和热重分析对石榴皮渣和PCNC进行了表征。结果表明,PCNC粒径为201 nm,Zeta电位值为-38.6 mV,具有纳米尺寸,且悬浮液具有良好的稳定性。微观结构分析展示出PCNC是具有较高结晶度的棒状结构。XRD测得石榴皮和PCNC的结晶度分别为33%和63%。FITR图表明石榴皮渣中的半纤维素和木质素被成功去除。热稳定分析显示PCNC热稳定性相较于石榴皮渣略有下降。

To increase the added value of pomegranate peel,pomegranate peel nanocellulose was prepared by alkali treatment and sodium hypochlorite bleaching,and pomegranate peel cellulose nanocrystals(PCNC)was successfully prepared by acid hydrolysis.The particle size and stability of PCNC were characterized,and the pomegranate pomace and PCNC were characterized by scanning electron microscopy(SEM),atomic force microscopy(AFM),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),differential scanning calorimetry(DSC),and thermogravimetric analysis(TGA).Results showed that the particle size of PCNC was 201 nm,the Zeta potential value was-38.6 mV,PCNC had nano-size,and the suspension of PCNC had good stability.The microstructure analysis showed that PCNC had high crystallinity and rod-like structure.The crystallinity of pomegranate peel and PCNC measured by XRD was 33%and 63%,respectively.FITR showed that hemicellulose and lignin in pomegranate peel residue were successfully removed.The thermal stability analysis showed that the thermal stability of PCNC was slightly lower than that of pomegranate pomace.