Dynamics of PEO-PPO-PEO block copolymer aggregation and silicate mesophase formation monitored by time-resolved ATR-FTIR spectroscopy

Abstract

The use of the attenuated total reflectance (ATR) technique to perform time-resolved FTIR spectroscopy analysis of the synthesis of SBA-15 silicate is reported. This spectroscopy is a powerful technique to investigate the assembly of surfactants and silicate species as well as surfactant micellization, as infrared bands are sensitive to local polarity and conformation of the surfactant chains. Critical micellization temperature (CMT), a key parameter that determines mesophase synthesis conditions and long-range ordering, is determined by in situ time-resolved ATR-FTIR under the conditions used to synthesize the mesophase. This technique allows also to determine the dynamics of the hydrolysis and condensation reactions of the silicate precursor.

Seasonal variations in arsenic mobility and bacterial diversity: The case study of Huangshui Creek, Shimen Realgar Mine, Hunan Province, China

“…Two broad and weak peaks were observed at 1636 cm -1 and 1415 cm -1 in the spectrum for sample As9 only. These were attributed to water bending and nitrate vibrations (Sánchez et al, 2008), respectively. Site As9 was located downstream of the Huangchang residential areas, and was likely affected by residential wastewater discharge and urban drainage.…”