Sol-gel synthesis and investigation of hybrid organic-inorganic borosilicate nanocomposites

Abstract

Borosilicate sols based on tetraethoxysilane and boric acid (or trimethyl borate) are synthesized. It is demonstrated that the introduction of organic oligomers into borosilicate sols changes the gelation kinetics, affects the composition and structure of the prepared nanocomposites, and makes it possible to produce socalled ormoborosils. Ultrasonic treatment has a strong effect on the gelation kinetics in borosilicate sols, the characteristics of the sol-gel system, and the structure and composition of the borosilicate composites. The phase composition of the synthesized xerogels is investigated by thermal analysis, and the chemical composition is studied by IR spectroscopy. The inference is made that the sol-gel synthesis of borosilicate nanocomposites leads to the formation of multilevel fractally aggregated nanocomposites.

Determination of sodium borosilicate bands in the IR spectrum of a multicomponent batch

“…In doubtful cases, their intensity, which is also a necessary but insufficient characteristic, must be considered. As a consequence, six bands in the IR spectrum of a five-component batch can be assigned to Determination of Sodium Borosilicate Bands in the IR Spectrum of a Multicomponent Batch 303 The proximity of the bands used in [1] to identify the Si -O -B bond and formation of borosilicate was noted previously. The results of calculating D p with the proposed method casts doubt on the distinguishability of the 676 and 664 cm -1 bands in experiment No.…”

“…If this section is set at 100%, then D 664 -676 = 1.8% will be equivalent to 0.3 mm on the abscissa. It is obvious that the coordinates of the bands indicated in [1] cannot be determined without a large error. In addition, the bands at 670 cm -1 (14.52 mm) and 670.5 cm -1 (15.09 mm), 664.8 cm -1 (15.16 mm) are assigned to [B(O, OH) 4 ] and [BO 4 ] tetrahedrons, while the band at 909 cm -1 (11 mm) close to 926 cm -1 [1] (D 909 -926 = 1.8%) are assigned to stretching vibrations of OH groups.…”

“…It is obvious that the coordinates of the bands indicated in [1] cannot be determined without a large error. In addition, the bands at 670 cm -1 (14.52 mm) and 670.5 cm -1 (15.09 mm), 664.8 cm -1 (15.16 mm) are assigned to [B(O, OH) 4 ] and [BO 4 ] tetrahedrons, while the band at 909 cm -1 (11 mm) close to 926 cm -1 [1] (D 909 -926 = 1.8%) are assigned to stretching vibrations of OH groups. In consideration of the above, the reliability of determining the Si -O -B bonds in [1,2] is suspect.…”

“…It is reported in [1] that 15 bands were determined in the IR spectrum of a substance obtained in the borosilicate system, tetragonal [BO 4 ], 8 bands were determined for B(OH) 3 , and four closely positioned bands at 664, 670, 672, and 676 cm -1 and one band at 926 cm -1 were determined for borosilicate. In [2], two bands, at 640 and 920 cm -1 , are indicated for the Si -O -B bond in the spectrum of 5ZnO × 15B 2 O 3 × 80SiO 2 .…”

“…In [2], two bands, at 640 and 920 cm -1 , are indicated for the Si -O -B bond in the spectrum of 5ZnO × 15B 2 O 3 × 80SiO 2 . These bands can only be assigned to borosilicate if there is a reference spectrum of the individual substance, but there are no such grounds in [1,2]. For this reason, in view of the limited information (or lack of information), a comparative analysis of the spectra of the individual components of a multicomponent substance would be useful.…”