Fundamental studies of novel inorganic–organic charged zwitterionic hybrids

Adsorption Performance of Heavy Metal Ions under Multifactorial Conditions by Synthesized Organic-Inorganic Hybrid Membranes

A series of hybridized charged membrane materials containing carboxyl and silyl groups were prepared via the epoxy ring-opening reaction and sol-gel methods using 3-glycidoxypropyltrimethoxysilane (WD-60) and polyethylene glycol 6000 (PEG-6000) as raw materials and DMF as a solvent. Scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analyzer/differential scanning calorimetry (TGA/DSC) analysis showed that the heat resistance of the polymerized materials could reach over 300 °C after hybridization. A comparison of the results of heavy metal lead and copper ions' adsorption tests on the materials at different times, temperatures, pHs, and concentrations showed that the hybridized membrane materials have good adsorption effects on heavy metals and better adsorption effects on lead ions. The maximum capacity obtained from optimized conditions for Cu²⁺ and Pb²⁺ ions were 0.331 and 5.012 mmol/g. The experiments proved that this material is indeed a new environmentally friendly, energy-saving, high-efficiency material. Moreover, their adsorptions for Cu²⁺ and Pb²⁺ ions will be evaluated as a model for the separation and recovery of heavy metal ions from wastewater.

Hierarchical bioresponsive nanocarriers for codelivery of curcumin and doxorubicin

Hierarchical responsive nanocarriers have received much attention for targeted delivery of chemotherapeutics. In this study, we designed pH and redox dual-stage responsive nanocarriers in the different delivery stages for co-delivery phosphorylated curcumin (p-Cur) with doxorubicin (Dox). The MSNs nanocarriers were functionalized via specific cleavable PEGylation and hydrogel coating crosslinked by disulfide bonds: MSNs as core load Dox; p-Cur encapsulated in hydrogel coating. In blood circulation, PEGylation endow the nanocarriers with long time during blood circulation; while in tumor tissue, PEG shells could be cleaved due to the pH-sensitive bond and expose the cationic hydrogel coating to improve cell uptake; while inside tumor cells, hydrogel coating could be cleaved due to the GSH and release the drugs. The results showed that the dual-responsive shells endowed the nanocarriers with tumor extracellular pH-triggered cell uptake and specific cancer cell target release. The synergistic effects of the p-Cur and Dox enhanced cellular apoptosis in Hela cells.

Preparation of zwitterionic hybrid polymer and its application for the removal of heavy metal ions from water

A series of zwitterionic hybrid polymers were prepared from the ring-opening polymerization of pyromellitic acid dianhydride (PMDA) and phenylaminomethyl trimethoxysilane (PAMTMS), and a subsequent sol-gel process. FTIR spectra confirmed the step products. TGA analysis showed that the thermal degradation temperature increased with an increase in PMDA content. As a typical example, sample B was used to separate Cu(2+) and Pb(2+) removal by adsorption. It was indicated that its adsorption for Cu(2+) and Pb(2+) followed Lagergren second-order kinetic model and Langmuir isotherm model, demonstrating that the adsorption process might be Langmuir monolayer adsorption. Meanwhile, it was found that the adsorption capacity of Pb(2+) on sample B is beyond 12 times higher than that of Cu(2+) in 0.1 mol dm(-3) aqueous solution, revealing that it has larger affinity for Pb(2+). The desorption efficiency of Cu(2+) and Pb(2+) in 1 mol dm(-3) HNO(3) solution reached up to 96 and 89%, respectively; indicating that they can be regenerated and recycled in industry. These findings suggest that they are promising adsorbents for the selective removal of Pb(2+) from Pb(2+)/Cu(2+) mixed aqueous solution, and can be applied to separate and recover the heavy metal ions from contaminated water and waste chemicals.