纳米铝粉在高密度碳氢燃料HF-X中的分散特性

Dispersion of Nano-Al in the High-density Hydrocarbon Fuels HF-X Suspension

为提高纳米铝粉在高密度碳氢燃料(HF-X)悬浮液中的分散稳定性,通过沉降速率法,探讨了分散剂含量、分散温度、纳米铝粉含量和粒度、悬浮液超声分散功率和超声时间对纳米铝粉在HF-X中分散性的影响;采用SEM比较了分散前后纳米铝粉的形貌,测试了纳米铝粉在分散剂/HF-X溶液中的接触角,分析了分散剂的影响机理。结果表明,含胺锚固基团的聚合物(HS)分散剂的悬浮液稳定分散时间明显长于含嵌段共聚物(HT)分散剂;随纳米铝粉含量和粒度增大,其在HF-X悬浮液中沉降速率增大,其中,在悬浮液中纳米铝粉的最大质量分数是7.5%,而达到10%就成为浆状物;随分散剂HS50质量浓度增加,纳米铝粉的沉降速率降低;HS50质量浓度为0.02g/mL时,纳米铝粉沉降速率为9.85×10^-6g/(cm^2·s),趋于恒定;随超声分散功率和时间增大,纳米铝粉的沉降速率降低,其对纳米铝粉的分散稳定性影响显著,而分散温度的影响最小;纳米铝粉在HS/HF-X溶液中的接触角明显大于在HT/HF-X中的接触角,含HS系列分散剂较好的分散稳定性与其高分子链之间对纳米铝粉的空间阻滞作用有关。

In order to improve the dispersion stability of nano-aluminum in high-density hydrocarbon fuels(HF-X) suspension, the effect of the dispersant mass fraction, dispersion temperature, mass fraction and granularity of nano-Al, ultrasonic dispersion power and time of nano-Al in HF-X suspension on the dispersibility of nano-Al were investigated by sedimentation rate test.The morphology of nano-aluminum powder before and after dispersion was compared by SEM, the contact angle of nano-Al in the dispersant/HF-X solution was tested and the influence mechanism of dispersant was analyzed.The results show that the dispersion time of suspension of polymer dispersant containing amine anchoring group (HS) is longer than that of dispersant containing block copolymer (HT).The sedimentation rate of nano-aluminum in the HF-X suspension increases with the increase in the mass fraction and particle size of nano-aluminum powder, among them, the maximum mass fraction of nano-aluminum powder in HF-X suspension is up to 7.5%, and the mixture becomes paste when it is 10%.With increasing the dispersant HS50 mass concentration, the sedimentation rate of nano-aluminum powder decreases.When mass concentration of HS50 is 0.02 g/mL, the sedimentation rate is 9.85×10 ^-6 g/(cm ^2·s), which tends to be constant.With increasing the ultrasonic dispersion power and time, the sedimentation rate of nano-aluminum powder decreases, which has a significant effect on the dispersion stability, while the dispersion temperature has little influence.The contact angle of nano-Al in HS/HF-X solution is much larger than that in HT/HF-X solution.The HS-series dispersants have better dispersion stability, which is related to the spatial retardation of polymer chain to nano-aluminum powder.