Effect of pH Variations on the Properties of Cyclodextrin‐Calixarene Nanosponges

Abstract

The pH‐responsive properties of cyclodextrin‐calixarene nanosponge co‐polymeric materials have been investigated. In particular, ISE‐H+ potentiometric titrations were carried out in order to evaluate the acid‐base properties and the actual amount of ionizable sites present in the materials. Moreover, the relevant pH‐dependent adsorption abilities were evaluated towards a set of selected model organic pollutant molecules by means of adsorption tests and by studying the corresponding adsorption isotherms. The latter ones could be suitably described by means of the Freundlich model. The whole of the experimental results enabled us to clarify some general aspects of the microscopic behavior of the nanosponges considered.

Straightforward preparation of highly loaded MWCNT–polyamine hybrids and their application in catalysis

“…The comparison of the amino group contents reported in Table 1 with those obtained by TGA showed that only 38% and 53% of the total amount of amino groups present in the cross-linked polymers were revealed by potentiometric titration for NH-But-MWCNT and NH-Xyl-MWCNT, respectively. This finding is consistent with the behaviour reported for some nanosponge materials, 95 which was explained with the presence in the materials of highly hydrophobic regions hardly accessible to the aqueous medium. It is worth noting that both materials showed similar results concerning the amino group content on their external surface, whereas material NH-Xyl-MWCNT exhibited a higher content of amino groups in its inner surface than NH-But-MWCNT ( Table 1 ).…”

Cyclodextrin‐Calixarene Nanosponges as Potential Platforms for pH‐Dependent Delivery of Tetracycline

“…The tests were performed at two different pH values, namely 4.4 and 6.7; the relevant results are collected in Table . The two pH values were chosen in order to be consistent with our previous works, and because they represent conditions occurring in different districts of the intestinal tract. In general, it has been shown that the sequestration properties of CyCaNSs may be significantly affected by pH variations, and largely depend on the electrostatic interactions between the guest and the co‐polymer matrix .…”

Nanosponge-C3N4 composites as photocatalysts for selective partial alcohol oxidation in aqueous suspension

“…Hence, they find widespread applications from pharmaceutical and chemical industries to agriculture and environmental engineering. Moreover, NSs can be profitably used for the sequestration of pollutants [17,18], as smart drug carrier/ delivery systems [19][20][21] or to obtain tailored materials with stimuli-sensitive properties [2,[22][23][24].…”