Tailoring the polyelectrolyte coating of metal nanoparticles
Tailoring the polyelectrolyte coating of metal nanoparticles
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DOI：
10.1021/jp0111665
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发表时间：
2001-07-26
影响因子：
3.3
通讯作者：
Caruso, F
中科院分区：
文献类型：
--
作者：
Gittins, DI;Caruso, F
如果纳米颗粒材料要用于胶体晶体或生物标记等应用，那么控制纳米颗粒材料的表面特性是必要的。通过调整聚合物的柔韧性和聚电解质吸附到高度弯曲的金表面上所涉及的静电力，通过改变悬浮链和球体的总盐浓度，结果表明可以实现金纳米颗粒的不可逆聚电解质包裹。通过连续将纳米颗粒暴露于相反电荷的聚电解质溶液中，聚电解质可以按逐层顺序沉积，产生涂有均匀聚电解质多层的金纳米颗粒。金属核溶解后形成自支撑聚电解质多层纳米胶囊。还发现，由阴离子吸附产生的金纳米颗粒表面电荷不足以克服离子和疏水性聚阴离子/聚阳离子相互作用，导致聚合物从高度弯曲的纳米颗粒表面解吸。将电荷固定在金纳米颗粒表面的一种成功方法是在聚电解质修饰之前共价连接阴离子硫醇。
Controlling the surface properties of nanoparticulate materials is necessary if they are to be exploited in applications such as colloidal crystals or biolabeling. By tailoring the polymer flexibility and the electrostatic forces involved in polyelectrolyte adsorption onto highly curved gold surfaces, through variation of the total salt concentrations suspending the chains and spheres, it is shown that irreversible polyelectrolyte wrapping of gold nanoparticles can be effected. By consecutively exposing the nanoparticles to polyelectrolyte solutions of opposite charge, polyelectrolytes can be deposited in a layer-by-layer sequence, yielding gold nanoparticles coated with uniform polyelectrolyte multilayers. Self-supporting polyelectrolyte multilayered nanocapsules are formed after dissolution of the metallic core. It has also been found that the gold nanoparticle surface charge, created by the adsorption of anions, is insufficient to overcome the ionic and hydrophobic polyanion/polycation interactions, resulting in polymer desorption from the highly curved nanoparticle surface. One successful method to immobilize the charge on the gold nanoparticle surface is to covalently attach an anionic thiol before polyelectrolyte modification.