Cellulose nanopaper (CNP) is a new potential candidate for flexible biopolymer substrate made of nanocellulose (NC). We systematically studied the effect of NC production from oil palm empty fruit bunch using the different types of acid hydrolysis based on sulphuric acid (NCs) as well as phosphoric acid (NCp) at varied temperatures regarding their morphology and crystallinity on the final properties of CNP. Both CNP from NCs (CNPs) and NCp (CNPp) exhibited higher optical transparency than conventional micropaper. In terms of mechanical properties, CNPs possessed an exceptional improvement of up to 200% compared to micropaper. CNPp specifically produced higher mechanical properties compared to CNPs. The stronger tensile strength of CNPp was attributed to a higher aspect ratio and thus a more flexible one compared to NCs. The greater transparency of CNPs than CNPp was postulated due to the formation of the densely packed order of intra-inter hydrogen bonds found in CNPs, which allowed more light to transmit through the film and reduce the light to scatter. In addition, the higher crystallinity with a smaller aspect ratio could also promote the higher transparency of CNPs to give the combination of influencing factors in explaining the level of transparency of CNP.

纤维素纳米纸 (CNP) 是由纳米纤维素 (NC) 制成的柔性生物聚合物基材的一种新的潜在候选材料。我们系统地研究了使用不同类型的基于硫酸 (NCs) 和磷酸 (NCp) 的酸水解在不同温度下从油棕空果串生产 NC 的形态和结晶度对 CNP 最终性能的影响. 来自 NCs (CNPs) 和 NCp (CNPp) 的 CNP 都表现出比传统缩微纸更高的光学透明度。在机械性能方面，与微型纸相比，CNPs 具有高达 200% 的出色改进。与 CNPs 相比，CNPp 特别产生了更高的机械性能。CNPp 更强的拉伸强度归因于更高的纵横比，因此与 NC 相比更灵活。假设 CNP 比 CNPp 具有更高的透明度，这是因为在 CNP 中形成了密集排列的内部氢键，这允许更多的光透过薄膜并减少光的散射。此外，具有较小纵横比的较高结晶度也可以促进CNP的较高透明度，从而给出解释CNP透明度水平的影响因素的组合。