Institut Charles Gerhardt, Ingénierie et Architectures Macromoléculaires, UMR CNRS 5253, Ecole Nationale Supérieure de Chimie de Montpellier, 8 Rue de l'Ecole Normale, 34296 Montpellier, France.
Langmuir. 2011 Apr 5;27(7):4057-67. doi: 10.1021/la1048826. Epub 2011 Mar 10.
The modification of silica nanoparticles with hexafluoropropylene oxide (HFPO) oligomers has been investigated. HFPO oligomers with two different average degrees of polymerization (DPn = 8 and 15) were first prepared by anionic ring-opening polymerization, deactivated by methanol, and in some cases postfunctionalized by aminopropyl(tri)ethoxysilane or allylamine. The "grafting onto" reactions of these oligomers were then carried out either on bare silica (reaction between a silanol surface and ethoxy-silanized HFPO) or on silica functionalized by amino groups (in an amidation reaction with methyl ester-ended HFPO) or mercapto groups (via the radical addition of allyl-functionalized HFPO). Hybrid nanoparticles thus obtained were characterized by solid-state (29)Si NMR and FTIR spectroscopies as well as elemental and thermogravimetric analyses. The results assessed a significant yield of covalent grafting of HFPO oligomers when performing the hydrolysis-condensation of ethoxylated HFPO on the bare silica surface, compared to the other two methods that merely led to physically adsorbed HFPO chains. Chemically grafted nanohybrids showed a high thermal stability (up to 400 °C) as well as a very low surface tension (typically 5 mN/m) compared to physisorbed complexes.
已经研究了用六氟丙烯氧化物（HFPO）低聚物对二氧化硅纳米粒子进行修饰。首先通过阴离子开环聚合制备了两种具有不同平均聚合度（DPn = 8 和 15）的 HFPO 低聚物，然后用甲醇将其失活，在某些情况下，用氨丙基（三）乙氧基硅烷或烯丙胺对其进行后官能化。然后，将这些低聚物的“接枝到”反应进行在裸露的二氧化硅上（醇羟基表面与乙氧基硅烷化的 HFPO 之间的反应）或在氨基官能化的二氧化硅上（与甲酯端 HFPO 的酰胺化反应）或巯基官能化的二氧化硅上（通过烯丙基官能化的 HFPO 的自由基加成）。通过固态（29）Si NMR 和 FTIR 光谱以及元素和热重分析对获得的混合纳米粒子进行了表征。结果表明，与其他两种仅导致物理吸附 HFPO 链的方法相比，在裸露的二氧化硅表面上进行乙氧基化 HFPO 的水解缩合时，HFPO 低聚物的共价接枝产率显著。与物理吸附的复合物相比，化学接枝的纳米杂化物表现出高的热稳定性（高达 400°C）和非常低的表面张力（通常为 5 mN/m）。
