Surface functionalization with phosphazene substrates, Part IV: Silica and Si(100) surface functionalization using cyclophosphazenes partially substituted with trialkoxysilane derivatives and PEG-750 monomethylether, 2,2,3,3-tetrafluoropropanol and 4-hydroxyazobenzene

• Published in: Designed monomers and polymers Vol. 10; no. 6; pp. 555 - 573
• Main Authors: Milani, Roberto, Sassi, Alessandro, Venzo, Alfonso, Bertani, Roberta, Fambri, Luca, Gleria, Mario
• Format: Journal Article
• Language: English
• Published: Lieden Taylor & Francis Group 01-01-2007; VSP
• Subjects: Applied sciences; Chemistry; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Organic chemistry; Organic polymers; PHOSPHAZENE SUBSTRATE; Physicochemistry of polymers; POLY(ETHYLENE GLYCOL)MONOMETHYLETHER; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; Preparations and properties; SPECTROSCOPY; SURFACE FUNCTIONALIZATION; THERMAL ANALYSIS; TRIALOXYSILANE DERIVATIVE; Surface functionalization; Surface reaction; Nitrogen phosphorus heterocycle; Photochromism; Organic silane; trialoxysilane derivative; Experimental study; Chemical coupling; Thin film; Ethylene oxide polymer; Azo compound; spectroscopy; Six membered ring; Preparation; Si; Silica gel; Star polymer; Silicon; phosphazene substrate; poly(ethylene glycol)monomethylether; Graft polymers; thermal analysis
• ISSN: 1385-772X; 1568-5551; 1568-5551
• DOI: 10.1163/156855507782401213

This paper deals with the possibility of functionalizing the surface of silicon-based materials by exploiting cyclophosphazenes containing suitable substituent groups. Thus, phosphazene trimers were prepared, containing about 50% of the reactive sites substituted by γ-aminopropyltriethoxy
silane (APTES), while the residual positions in the cycle contain poly(ethylene glycol) monomethylether (MW approx. 750; PEG-750-ME), tetrafluoropropanol (TFP) and 4-hydroxyazobenzene (AzB). Using these novel materials we succeeded in surface functionalizing SiO
2
beads in the coating
of silicon wafers or sodalime slides and in the preparation of cyclophosphazene-based monoliths in the presence of hydrolyzed TEOS by sol-gel technique. The whole series of products has been characterized by standard spectroscopic (IR, UV-Vis,
1
H-,
13
C-,
29
Si-
and
31
P-NMR, both in solution and in solid state) and thermal (DSC and DMTA) techniques. This approach to the surface functionalization of silicon-based materials containing carefully selected substituents is completely general and can be used to attach to the hydroxylated surfaces
practically any type of nucleophile that can be supported on the cyclophosphazene ring.