ABSTRACT

The aim of this study was to investigate the effect of using silver and copper nano-suspensions in mixture with resin, upon screw withdrawal capacity (in face and edge directions) and hardness (at different depths of penetration) of particleboards. An aqueous-suspension of 200 ppm silver and copper was mixed with urea-formaldehyde resin at two levels of 100 and 150 mL/kg dry weight wood particles. The size range of at least 70% of nano-particles was 20–90 nm. The results revealed a significant increase in screw withdrawal capacity and hardness by adding the nanometals to composite mats. The increased properties were partially attributed to an improvement in heat transfer in mats that facilitated the curing of resin. Moreover, theoretical simulations based on density functional theory (DFT) clearly demonstrated high adsorption energy of silver and copper atoms on cellulose and hemicellulose polymers; this contributed to a formation of additional bonds throughout the composite matrix, which in turns improved the board properties.

摘要

本研究的目的是研究使用与树脂混合的银和铜纳米悬浮液对刨花板的螺杆抽出能力（在正面和边缘方向）和硬度（在不同的穿透深度）的影响。将 200 ppm 银和铜的水性悬浮液与脲醛树脂以 100 和 150 mL/kg 干重木颗粒的两个水平混合。至少 70% 的纳米颗粒的尺寸范围为 20-90 nm。结果表明，通过将纳米金属添加到复合垫中，螺钉的拔出能力和硬度显着增加。增加的性能部分归因于促进树脂固化的垫中传热的改进。而且，基于密度泛函理论 (DFT) 的理论模拟清楚地证明了银和铜原子在纤维素和半纤维素聚合物上的高吸附能；这有助于在整个复合基体中形成额外的键，从而改善了板材的性能。