Hypothesis

Finding an efficient dispersant for obtaining a good dispersion of 5-nm detonation nanodiamond (DND) is always a challenge. Two newly designed diblock copolymers, both poly(ammonium methacrylate)-block-poly(2-phenoxyethyl acrylate) (PMA-b-PBEA) but with different molar ratios of PMA to PBEA, were proposed to be efficient dispersants in stabilizing the concentrated aqueous suspensions of DND.

Experiments

The dispersion efficiency of dispersants for DND in aqueous suspensions was studied by the measurements of particle size, sedimentation property, and rheological behavior. The interactions between the added dispersants and DND were identified by the zeta potential and adsorption analyses. Calculations based on Derjaguin-Landau-Verwey-Overbeek (DLVO) theory were conducted for clarifying the dominant parameters relating to the dispersion efficiency of dispersants.

Findings

Compared with the commercially popular dispersant ammonium polyacrylate, these two diblock dispersants exhibited superior efficiency in the stabilization of DND suspensions. Using the diblock copolymers as dispersants, good dispersion stability in a DND suspension with an extremely high solid content of 30 wt% was achieved. According to experimental analyses and based on DLVO calculations, a low number of accompanied counter-ions, high adsorption capability, and thick PMA-b-PBEA adsorption layer are the main reasons for the extremely high dispersion efficiency of the two new dispersants.

中文翻译：

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使用新型二嵌段分散剂制备高度分散和浓缩的纳米金刚石水悬浮液

假设

寻找有效的分散剂以获得5nm爆轰纳米金刚石（DND）的良好分散一直是一个挑战。两个新设计的二嵌段共聚物，均聚（甲基丙烯酸铵） -嵌段-聚（2-苯氧基乙基丙烯酸酯）（PMA- b -PBEA），但用PMA至PBEA的不同摩尔比，提出了是有效的分散剂稳定的浓缩的含水DND的暂停。

实验

通过测量粒径，沉降性能和流变行为，研究了DND分散剂在水悬浮液中的分散效率。通过ζ电势和吸附分析鉴定了添加的分散剂和DND之间的相互作用。进行了基于Derjaguin-Landau-Verwey-Overbeek（DLVO）理论的计算，以阐明与分散剂的分散效率有关的主要参数。

发现

与商业上流行的分散剂聚丙烯酸铵相比，这两种二嵌段分散剂在稳定DND悬浮液方面表现出优异的效率。使用二嵌段共聚物作为分散剂，在具有30wt％的极高固含量的DND悬浮液中获得了良好的分散稳定性。根据实验分析并基于DLVO计算，伴随的抗衡离子数量少，吸附能力强以及PMA- b -PBEA吸附层厚是两种新型分散剂具有极高分散效率的主要原因。