凹凸棒对纳米纤维素基气凝胶结构及性能的影响研究

Effect of Attapulgite on the Structure and Properties of Cellulose Nanofibrils Composite Aerogel

中文关键词:  纳米纤维素  凹凸棒  气凝胶  增强材料

Key Words:nanocellulose  attapulgite  aerogel  reinforced material

中文摘要:

      以纤维素纳米纤丝（CNF）作为原料，以凹凸棒（ATP）作为增强材料，通过制备不同质量比的纳米纤维素-凹凸棒（CNF-ATP）悬浮液；然后利用液氮梯度冷冻和冷冻干燥的方法制备了CNF-ATP复合气凝胶。采用傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）、热重分析（TG）等手段对制备所得气凝胶样品进行分析，探究了不同ATP的添加量对CNF-ATP气凝胶结构的影响。结果表明，CNF-ATP的前驱体悬浮液Zeta电位为-31.20 mV，粒径分布主要在1000 nm以上。随着ATP添加量的提高，CNF-ATP复合气凝胶的湿、热稳定性及抗应变能力也显著提升，热分解温度超过了305 ℃，在溶液中浸渍72 h仍能保持湿稳定性。同时，研究发现当CNF和ATP质量比为2∶1时，CNF-ATP复合气凝胶的抗应变能力和柔韧平衡性最佳，形变承受程度可高达45%。该比例下CNF-ATP复合气凝胶的湿、热稳定性也得到了极大程度的提升，ATP在气凝胶孔壁上的分布状况表现了其分散性良好。

Abstract:

      Using cellulose nanofibers （CNF） as raw material and attapulgite （ATP） as reinforcing material， CNF-ATP suspension with different ratios were prepared， and then CNF-ATP composite aerogels prepared by liquid nitrogen gradient freezing and freeze-drying. The effect of different amount of ATP on the structure of CNF-ATP aerogel was analyzed by means of infrared spectroscopy （FT-IR）， X-ray diffraction （XRD） and thermogravimetric analysis （TG）. The results showed that the Zeta potential of the precursor suspension of CNF-ATP was -31.20 mV， and the particle size distribution was mainly above 1000 nm. As the amount of ATP added increasing， the humidity and heat stability and strain resistance of the CNF-ATP composite aerogel were also significantly improved. The thermal decomposition temperature exceeded 305 ℃， and the humidity stability was maintained after 72 h of immersion in the solution. At the same time， the study found that when the mass ratio of CNF and ATP was 2∶1， the CNF-ATP composite aerogel had the best strain resistance and flexibility balance， and the deformation tolerance could be as high as 45%. The humidity and heat stability of the CNF-ATP composite aerogel at this ratio has also been improved to the greatest extent， and the distribution of ATP on the pore wall of the aerogel showed its good dispersion.