不同方法制备浒苔纳米纤维素及其性质表征

杨楠; 王雷; 高昕; 许加超; 付晓婷

doi:10.13386/j.issn1002-0306.2024010088

不同方法制备浒苔纳米纤维素及其性质表征

Preparation and Characterization of Nanocellulose from Ulva prolifera by Different Methods

摘要

摘要: 以绿潮优势藻浒苔为原料，通过碱处理、漂白处理提取浒苔纤维素（UPC），得率为23.61%。采用硫酸水解法、盐酸水解法和2,2,6,6-四甲基哌啶-1-氧基自由基（TEMPO）氧化法分别制备浒苔纳米纤维素（UPCNC-S、UPCNC-H和UPCNC-T），通过得率、傅里叶红外光谱（Fourier transform infrared spectroscopy，FTIR）、X射线衍射（X-ray diffraction，XRD）、热重分析（Thermogravimetric analysis，TGA）、扫描电镜（Scanning electron microscopy，SEM）、粒径、电位、色度对不同方法制备的纳米纤维素的结构及微观形貌进行表征和比较。结果表明：三种制备方法得到的纳米纤维素得率分别为10.07%（UPCNC-S）、32.48%（UPCNC-H）和26.63%（UPCNC-T），其晶型和结构均未破坏，并且结晶度较纤维素均有所提高，分别为72.11%（UPCNC-S）、77.16%（UPCNC-H）和66.53%（UPCNC-T）。硫酸水解不利于纳米纤维素的热稳定性，而盐酸水解得到的UPCNC-H热稳定性最佳。UPCNC-T和UPCNC-H均呈现短棒状形貌，粒径尺寸分别集中在430 nm和610 nm附近，硫酸水解法能够制备出短棒状和部分球形纳米纤维素，粒径尺寸最小，主要分布在300~400 nm之间。三种纳米纤维素的Zeta电位值均小于−30 mV，悬浮液均具有较佳的稳定性。UPCNC-S的颜色略微偏黄，白度值最低，而UPCNC-H和UPCNC-T整体颜色较为洁白。综上，本研究制备的浒苔纳米纤维素具有结晶度高、分散性好、粒径尺寸小等优良特性，为实现绿潮浒苔的高值化利用提供了一定的理论基础。

Abstract: Ulva prolifera, as the dominant species of the green macro-algal bloom, was used as the raw material to prepare cellulose (UPC) by alkali extraction and bleaching treatment with a yield of 23.61%. Nanocelluloses of UPCNC-S, UPCNC-H, and UPCNC-T were prepared using sulfuric acid hydrolysis, hydrochloric acid hydrolysis, and TEMPO oxidation methods, respectively. The structure and micro-morphology of the prepared nanocelluloses were characterized and compared based on yield, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), particle size, Zeta potential, and chromaticity value. The results showed that the yields of the nanocelluloses prepared by three methods were 10.07% of UPCNC-S, 32.48% of UPCNC-H, and 26.63% of UPCNC-T, respectively. All three methods did not damage the crystal form and the structure of the cellulose showed, an increase in crystallinity and reached 72.11% (UPCNC-S), 77.16% (UPCNC-H), and 66.53% (UPCNC-T). The thermal stability of nanocellulose UPCNC-S produced by sulfuric acid was to the weakest, while that of UPCNC-H was the optimal. In terms of morphological features, both UPCNC-T and UPCNC-H exhibited short-shaped morphology, with particle sizes concentrated around 430 nm and 610 nm, respectively. In addition to the short rod structure, partially spherical nanocellulose was produced by sulfuric acid hydrolysis, with the smallest particle sizes ranging from 300 nm to 400 nm. The Zeta potential values of the three types of nanocellulose were all less than −30 mV, indicating good stability in suspension. Besides, the color of UPCNC-S was slightly yellowish with the lowest whiteness value, while UPCNC-H and UPCNC-T both showed the whitish appearance. In summary, the nanocellulose prepared from Ulva prolifera in this study exhibited excellent characteristics such as high crystallinity, good dispersion, and small particle sizes, which provided a theoretical basis for the high-value utilization of Ulva prolifera.