Prepare porous silica nanospheres for water sustainability: high efficient and recyclable adsorbent for cationic organic dyes

Preparation of Ag Nanoclusters-Modified Non-Sintered Silica Ceramic-Like Nanosheet for Removing Dyes and Bacteria from Water

PURPOSE

Worldwide water contamination treatment and water security are essential for all living organisms. Among various water contaminants, dye, and bacteria pollution needs to be solved urgently.

METHODS AND RESULTS

In this work, a ceramic sheet from monodisperse, porous silica nanospheres (SiO2 NSs) with an average diameter of 220 was prepared. The prepared SiO2 ceramic sheets were investigated as a "filtration" material in removing dyes (alcian blue, AB; and methylene blue, MB) and bacteria (E. coli and S. aureus). The obtained sheets had efficient adsorption efficiency of 98.72% (for AB) and 97.35% (for MB), and a high adsorption capacity for AB is 220 (mg/g), for MB is 176 (mg/g). Furthermore, these SiO2 ceramic sheets had a high recycling capability for removing dyes by calcination. Being modified by Ag nanoclusters, the ceramic sheets present a strong bactericidal function.

CONCLUSION

Our results demonstrated that the obtained SiO2 non-sintered ceramic sheets is rapid and efficient in the filtration of dyes and bacteria from polluted water.

A hydrolytically stable cage-based metal–organic framework containing two types of building blocks for the adsorption of iodine and dyes

A metal–organic framework (SCNU-Z4) with high chemical stability in water and common organic solvents showed ability for iodine and dye adsorption.

pH and folic acid dual responsive polysaccharide nanospheres used for nuclear targeted cancer chemotherapy

Ideal nanoscale drug delivery system (DDS) should be biocompatible, having targeted recognition and controlled release properties. In this work, monodispersed, doxorubicin (Dox) loaded chitosan (Cts) nanospheres functionalized by mesoporous SiO₂ and folic acid (FA) were prepared, briefly named as DCSF NSs. The prepared raspberry-like DCSF NSs had an average size of 440 nm and drug loading efficiency (DLE) of 42.61%. The drug release results confirmed that the release of Dox could be controlled by pH change. Cell apoptosis results indicated that the obtained DCSF NSs could kill 90% of MCF-7 cells in 48 h. Confocal laser scanning microscopy (CLSM) results further revealed that folic acid could mediate the cellular uptake of DCSF NSs. These results demonstrated that the obtained DCSF NSs were pH-responsive, folic acid-triggered nuclear targeted, which can be used as ideal DDS for tumor chemotherapy.

Environmentally Friendly Gelatin/β-Cyclodextrin Composite Fiber Adsorbents for the Efficient Removal of Dyes from Wastewater

In this paper, environmentally friendly gelatin/β-cyclodextrin (β-CD) composite fiber adsorbents prepared by electrospinning were used for the removal of dyes from wastewater. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and a universal materials tester were employed to characterize the internal structures, surface morphologies and mechanical strength of the composite fiber adsorbents. Additionally, the fiber was evaluated as an adsorbent for the removal of methylene blue (MB) from aqueous solution. The effects of the raw material ratio, pH, temperature, concentration and adsorption time were studied. The results show that the gelatin/β-CD composite fiber adsorbents possess excellent mechanical strength and high adsorption efficiency for MB. The adsorption equilibrium and adsorption kinetics are well-described by the Langmuir isotherm model and the pseudo-second-order kinetic model, respectively. The theoretical maximum adsorption capacity is 47.4 mg·g-1. Additionally, after nine successive desorption-adsorption cycles, the removal rate is still over 70%. Moreover, the gelatin/β-CD composite fiber adsorbents exhibit excellent adsorption capability for basic fuchsin, gentian violet, brilliant blue R and malachite green dyes. Therefore, owing to the characteristics of degradability, low cost and high-efficiency, the gelatin/β-CD composite fiber can be used as an efficient adsorbent for the removal of dyes from wastewater.

Encapsulation of green tea polyphenol by pH responsive, antibacterial, alginate microgels used for minimally invasive treatment of bone infection

The treatment of bone infection requires drug carriers take large number of cargo, be antibacterial, promote proliferation and differentiation of osteoblasts. Herein, we proposed a strategy of preparing pH responsive, antibacterial, multistage structured microspheres encapsulated with green tea polyphenol used for minimally invasive treatment of bone infection. Tea polyphenol (TP) were encapsulated by porous silica nanospheres (SiO₂ NSs). Then, sodium alginate (SA) microgel spheres (MSs) were prepared to encapsulate a lot of TP loaded SiO₂ NSs. The outer layer of obtained TP@SiO₂@SA microgel spheres were further wrapped by pH sensitive CaCO₃. Mineral out-layer of the composite microspheres is used to neutralize the acidic environment caused by bacterial infection. At the same time, encapsulated TP is released pH sensitively to resist oxidative stress. Our results exhibited excellent drug delivery properties including drug loading efficiency (DLE) of 92.96% and drug loading content (DLC) of 19.62%. Besides, results demonstrated that TP@SiO₂@SA@CaCO₃ MSs can effectively kill Staphylococcus aureus and promote proliferation and differentiation of osteoblasts under stimulation of H₂O₂ at pH = 5.5.