Core-shell structured dual-mesoporous silica spheres (DMSS) that possess smaller pores (2.0 nm) in the shell and larger tunable pores (12.8-18.5 nm) in the core have been successfully synthesized by utilizing an amphiphilic block copolymer (polystyrene-b-poly (acrylic acid), PS-b-PAA) and cetyl trimethyl ammonium bromide (CTAB) as cotemplates. The thickness of the shells and the larger pore size in the core could be easily tuned by changing the amounts of TEOS and the hydrophobic block (PS) length during synthesis, respectively. By encapsulating hydrophobic magnetite nanoparticles into the cores, superparamagnetic dual-mesoporous silica spheres were obtained. Drug storage and release testing results showed that the diffusing rate of the stored drug could be efficiently controlled by changing the shell thickness of DMSS.

中文翻译：

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孔径可调、壳厚可控的核壳结构双介孔二氧化硅球体的合成

利用两亲性嵌段共聚物（聚苯乙烯-b）成功地合成了核壳结构的双介孔二氧化硅球（DMSS），其壳中具有较小的孔（2.0 nm），核中具有较大的可调孔（12.8-18.5 nm）。 -聚（丙烯酸）、PS-b-PAA）和十六烷基三甲基溴化铵（CTAB）作为共模板。通过在合成过程中分别改变 TEOS 的量和疏水嵌段 (PS) 的长度，可以很容易地调整壳的厚度和核中较大的孔径。通过将疏水性磁铁矿纳米粒子封装到核中，获得了超顺磁性双介孔二氧化硅球体。药物储存和释放测试结果表明，通过改变 DMSS 的壳厚度可以有效控制储存药物的扩散速率。