作者:Anna Peled、Maria Naddaka、Jean-Paul Lellouche
DOI:10.1039/c1jm00055a
日期:——
Monodisperse, colloidal silica nanoparticles (NPs) are being widely investigated due to a variety of applications in various fields of chemistry. Many works utilize incorporation of various functional groups to silica NPs for their further modifications. However, at present no benzophenone (BPh) or phenyl azide (PA) containing silica NPs exist. Upon UV irradiation BPh and PA form highly reactive species that react with any organic material. Here we present a convenient method for the preparation of novel hybrid photoreactive silica NPs (denoted as SiO2@photoreactive group) prepared by co-condensation of photoreactive organosilanes and tetraethyl orthosilicate (TEOS) to obtain SiO2@PA and SiO2@BPh NPs. The reactivity of these two types of silica NPs is compared to that of perfluorinated phenyl azide (PFPA) based SiO2 NPs. The reactivity evaluation is carried out by the reaction of the three types of SiO2 NPs with highly inert poly(2-chloro-paraxylelene) films. It is found that, in contrast to what is stated in the literature, PA is much more reactive than PFPA, when dealing with solid state photochemical reactions. Next, photoreactive silica NPs on polymer films are used as an intermediate functional phase for a second modification step using silane-based chemistry. A successful incorporation of amine functionality onto silica NPs is achieved by their reaction with 3-aminopropyltriethoxysilane (APTES) and is verified by fluorescence microscopy. This strategy provides a general and versatile route to efficient functionalization of silica by light.
由于单分散胶体二氧化硅纳米粒子(NPs)在各个化学领域的广泛应用,人们正在对其进行广泛研究。许多研究利用在二氧化硅 NPs 中加入各种官能团的方法对其进行进一步改性。然而,目前还没有含有二苯甲酮(BPh)或苯基叠氮化物(PA)的二氧化硅 NPs。在紫外线照射下,二苯甲酮(BPh)和苯基叠氮化物(PA)会形成高活性物质,与任何有机材料发生反应。在此,我们介绍一种制备新型混合光活性二氧化硅 NPs(称为 SiO2@光活性基团)的简便方法,该方法通过光活性有机硅烷和原硅酸四乙酯(TEOS)的共缩合制备 SiO2@PA 和 SiO2@BPh NPs。这两种二氧化硅 NPs 的反应活性与基于全氟苯基叠氮化物(PFPA)的 SiO2 NPs 的反应活性进行了比较。反应性评估是通过这三种二氧化硅氮氧化物与高惰性聚(2-氯对二甲苯)薄膜的反应进行的。结果发现,在固态光化学反应中,PA 的反应活性远高于 PFPA,这与文献中的说法不同。接下来,聚合物薄膜上的光活性二氧化硅 NPs 被用作中间功能相,利用硅烷化学进行第二步改性。通过与 3-aminopropyltriethoxysilane (APTES) 反应,成功地在二氧化硅 NPs 上加入了胺官能团,并通过荧光显微镜进行了验证。这一策略为通过光对二氧化硅进行高效官能化提供了一条通用的途径。