Photoacoustic infrared spectroscopic studies of silica surface functionalized by dendrimers

Fourier Transform Infrared Photoacoustic Spectroscopy (FT-IR/PAS) is one of the types of classic Infrared Spectroscopy (IR), which is based on recording the pressure changes in a measuring cell, caused by vibrations of particular bonds, triggered by periodically changed wavelengths of infrared radiation. The main advantages offered by FT-IR/PAS technique are the possibility of characterization of non-homogenous or opaque materials and no need of samples dilution. The following article is concerned with characterization of a series of silica-based hybrid materials grafted with dendritic structures, by FT-IR/PAS measurements. The study involved immobilization of poly(amidoamine) (PAMAM) and poly(hydroxyl) (bis-MPA-OH) dendrimers on silica platform with either isocyanate or maleimide surface functional groups. It was expected that the loading of dendritic structures on silica platforms was relatively low, however, the recorded spectra showed distinct and measurable signals originating from each bonding type. Unless the signals had overlapped each other, the distinguished bands were assigned to several functional groups, which confirmed successful anchoring of dendritic structures on silica matrices.