This article reports on an investigation into the ability of minced banana peel to extract lead and copper ions from water and the parameters involved in this process. The kinetics of copper and lead uptake reached equilibrium in 10 min and the extraction of metals ions was favorable above pH 3. The medium was characterized by FTIR, which showed absorption bands of carboxylic and amine groups at 1730 and 889 cm1, respectively. The adsorption isotherm fitted by Langmuir’s model showed maximum adsorption capacities of 0.33 and 0.20 mmol g−1 (or 20.97 and 41.44 mg g−1) for Cu(II) and Pb(II), respectively. Minced banana peel was applied in the preconcentration system and showed approximately 20-fold enrichment factor and the column was reused for 11 cycles without loss in the percentage of recovery. The proposed method was applied in the determination of Cu(II) and Pb(II) in a sample of raw river water and was validated by comparison with a standard reference material.

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Mesoporous silicas of the MSU-X type, made with nonionic polyethylenoxide-based (PEO) surfactants, were synthesized according to a two-step process that gives intermediary stable hybrid micelles. The influence of the various synthesis parameters, such as the silica concentration, the addition of a swelling agent (TMB:  trimethyl-1,3,5 benzene), the condensation catalyst (NaF), and the temperature of silica condensation, was systematically explored, especially their influence on the material pore size. Surprisingly, changing the silica over surfactant ratio does not modify the silica wall thickness but the other parameters have a strong effect on the final pore size. Considering the model of hybrid micelles that was previously reported (Boissière et al. Chem. Mater. 2001, 13, 3580), we explained the effect of the different parameters by a classical swelling effect of the hydrophobic micelle core for TMB, whereas the modulation of the hydrophilicity of the PEO chains (for temperature) or that of the silica oligomers (for NaF) describes correctly the variations observed. Finally, the cumulative effect of these parameters is demonstrated and we show that materials with narrow pore size distributions tuned between 2.5 and 5 nm can be obtained without changing the surfactant nor adding any swelling agent, by varying only the synthesis parameters.

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