Design of a Cross-linked PTHF-Based Network as an Oil/Organic Solvent Sorbent

Coherent Loading-Deloading Mechanism in Polymeric Nanohybrid Network Structures

Physically cross-linked gels have unique advantages of repeated swelling and shrinking of network structures, where the stability of gels at the swelled phase, particularly under ionic conditions, is extremely critical. In this study, it has been shown that functionalized nanofillers and polar solvents can increase the network densities of physically cross-linked gels with higher dimensional stability by increasing the polar and electrostatic interactions. The characteristic nonbonded interactions of CNTs with ionic solvents have been utilized for the controlled swelling of toughened double-network gels as the function of pH and time. The swelling of the overall gel morphology is found to be important for the release of analytes; however, the functional cross-sectional sites in the nanohybrids hold the key for desorption kinetics. The selection of interactive functional moieties in the nanohybrids and analytes has led to the development of highly efficient and controlled release media. The electrostatic interaction of analytes with functionally and dimensionally stable gels with controlled porosity indicates a clear structure-property correlation, which could be exploited to design and fabricate efficient drug delivery vehicles and rapid surface decontaminants.

The preparation of CaCO3-polyalkoxysilane porous nanocomposites as effective sorbent for oil spill removal

The novel porous nanocomposite sorbent was synthesized by the condensation of the diol monomer with the alkoxysilane cross-linker at moderately high temperatures in the presence of nano-CaCO₃ particles. The structural, thermal, and morphological properties of the nanocomposite sorbents were determined by using Fourier transform infrared spectroscopy (FTIR), solid-state CPMAS ¹³C and ²⁹Si NMR, scanning electron microscope (SEM), and thermal gravimetric analysis (TGA). Adding nano-CaCO₃ to the network structure of the polymer not only provided pores to the sorbent but also enhanced its sorption capacity towards various oils and toxic organic solvents. The nanocomposite sorbent exhibited excellent absorption capacity for different toxic organic solvents and oils and great reusability for ten cycles. Moreover, the obtained sorbent material selectively absorbed organic liquids from the surface and bottom of the water without any capacity change owing to their hydrophobicity and oleophilicity. These features of the nanocomposite make it a potential sorbent for the cleaning of oils and oil derivative organic contaminants from the environment.

Sorption of hazardous industrial organic liquids with environmentally friendly functionalized cellulosic sorbents

The performances of five cellulosic polymers with different functional groups (cellulose, cellulose acetate, cellulose phosphate, chitosan, and chitin) as sorbents of seven frequently used hazardous polar organic liquids (acrolein, butanone peroxide, epichlorohydrin, formaldehyde, furfuryl alcohol, propylene oxide, and vinyl acetate) are investigated in this study. Amongst the cellulosic sorbents, cellulose phosphate exhibited enhanced sorption properties (as high as 3.09–7.03 g/g) against all seven polar organic liquids investigated, and chitosan and chitin also demonstrated comparable sorption efficiencies (2.28–7.72 g/g and 2.55–5.86 g/g, respectively) to those of cellulose phosphate. According to our investigation, the enhanced sorption efficiency could be achieved due to low powder density of cellulose phosphate, which is caused by the weak intramolecular interaction amongst the polymer chains. In addition, cellulose phosphate, chitosan, and chitin also showed enhanced absorbed solvent recovery percents (71.4, 60.6, and 61.1%, respectively, in average) compared with that of pristine cellulose (43.8%). With excellent sorption efficiency, enhanced solvent recovery rate, and reusability after drying, these functionalized cellulosic sorbents can be excellent candidates to replace the conventional carbon and vermiculites-based sorbents, especially for liquid polar organic spill sorption.