Soft matter-water interface: general discussion.
Soft matter-water interface: general discussion.
复制标题
软物质-水界面：一般讨论。
DOI：
10.1039/d3fd90066e
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发表时间：
2024
影响因子：
3.4
通讯作者：
Backus EHG
中科院分区：
文献类型：
--
作者：
Backus EHG
Hidefumi Naito对Monica Olvera de拉克鲁斯的论文展开了讨论：首先，为什么氯化钠不会诱导纳米颗粒聚集？一价阳离子和二价阳离子在聚集体中有什么区别？其次，“二价阳离子重要”和“钙离子重要”哪个是真的？我的意思是，如果我们用镁离子代替钙离子，纳米颗粒聚集有什么不同吗？Monica Olvera de拉克鲁斯回答说：实际上，在强负电荷颗粒中，如ds-DNA-Au纳米颗粒，在0.750 M NaCl和更高浓度下也可以观察到沉淀成晶体1，尽管在ds-DNA-Au纳米颗粒的情况下，沉淀（盐析）发生在0.150 M CaCl 2和更高浓度下。因此，在强负电荷纳米颗粒的盐析的情况下，二价离子比单价离子更重要。在我们目前的ss-DNA-Au纳米颗粒的情况下，我们确实观察到了晶体在加入NaCl时的收缩，前提是系统中存在一定量的CaCl。其它二价盐包括MgCl 2也引起ss-DNA-Au纳米颗粒的类似沉淀以及进一步添加盐的再膨胀（不同二价盐的结果将在不久的将来公布）。
Hidefumi Naito opened a discussion of the paper by Monica Olvera de la Cruz: Firstly, why does sodium chloride not induce nanoparticle aggregation? What is the difference between monovalent and divalent cations for that aggregation? Secondly, which is true,“divalent cation is important” or “calcium ion is important”? What I mean is, if we use magnesium ions instead of calcium ions, is there any difference for nanoparticle aggregation?Monica Olvera de la Cruz replied: Actually, in strongly negatively charged particles, such as ds-DNA-Au nanoparticles, the precipitation into crystals is also seen at 0.750 M of NaCl and above1 although in that case of ds-DNA-Au nanoparticles, the precipitation (salting-out) occurs with CaCl2 at concentrations 0.150 M and above. Therefore, divalent ions are more important than monovalent in the case of the salting-out of strongly negatively charged nanoparticles. In our present case of ss-DNA-Au nanoparticles we do observe contractions of crystals adding NaCl provided there is some amount of CaCl in the system. Other divalent salts including MgCl2 also cause similar precipitation of ss-DNA-Au nanoparticles as well as re-expansion with further addition of salt (results with different divalent salts will be published in the near future).