Integrated Treatment of Mining Dam Wastewater With Quaternized Chitosan and Pan/hpmc/agno3 Nanostructured Hydrophylic Membranes

This study was developed a novel nanostructured membrane by electrospinning process, from polyacrylonitrile (PAN) modify by hydroxypropyl methylcellulose (HPMC) polymers containing AgNO3, to be used as a filter in an integrated wastewater dam treatment process to reuse it as drinking water. Different formulations (108 samples) were electrospun from PAN and (0, 5, 10%w) HPMC and (0, 0.5, 1%w) solutions to selected a more efficient formulation in water disinfection and higher hydrophilic character of the membrane to flow performance in the wastewater treatment. The PAN and HPMC phases in membranes were characterize by infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The nanostructured membranes (SEM) were characterized by thickness fiber between 251 ± 58 and 306 ± 49 nm and lower fiber/membrane volume relations. The presence of HPMC and AgNO3 in membrane formulation endows superhydrophilicity and permeability increase which up to 21,151 ± 445 L.m-2.h-1. After filtration process with PAN/HPMC/AgNO3, all the tested water potability indexes were achieved. The primary treatment, using quaternized chitosan reduced the turbidity parameter from 19,000 NTU to 14 NTU, and after filtration with nanostructured membrane, to levels was below 1 NTU and pathogenic potential removed (Total Coliform and Escherichia coli). The results of this study indicated that the hydrophilic nanostructured membranes PAN/10%HPMC/1%AgNO3 have adequate properties to potential wastewater treatment mining for reuse. It´s give a sustainable strategy for managing wastewater which should be reduce the volume of water in the tailing’s dams and contributes to increasing the stability of dams and reducing risks with catastrophic environmental impact.

Nanofluidic osmotic power generators – advanced nanoporous membranes and nanochannels for blue energy harvesting

Advanced nanostructured membranes with high ion flux and selectivity bring new opportunities for generating clean energy by exploiting the osmotic pressure difference between water sources of different salinities.

Electrospun Active Media Based on Polyvinylidene Fluoride (PVDF)-Graphene-TiO2 Nanocomposite Materials for Methanol and Acetaldehyde Gas-Phase Abatement

The abatement of organic pollutants by TiO2 photocatalysis has been established as one of the benchmark applications of advanced oxidation processes for both liquid and gas phase purification. Such solution is particularly suitable for indoor air pollution where volatile organic compounds (VOCs) represent a class of chemicals of high concern for their adverse effects on both environment and human health. However, different shortcomings still affects TiO2 photocatalytic performance in terms of weak adsorptivity and fast electron-hole recombination, limiting its applicability. As a result, different strategies have been investigated over the last years in order to promote a higher TiO2 photo-efficiency. In this study we used electrospun (PVDF) nanofibers as a support for the photo catalytic system obtained by coupling graphene based materials and TiO2 during solvothermal synthesis. The resultant nanostructured membranes have been tested for acetaldehyde and methanol degradation under UV light showing an increase in the photocatalytic activity compared to bare TiO2. Such results may be ascribed to the decrease of band-gap energy and to increased electron mobility in the photocatalytic nanocomposite.

Doxycycline and Zinc Loaded Silica-Nanofibrous Polymers as Biomaterials for Bone Regeneration

The main target of bone tissue engineering is to design biomaterials that support bone regeneration and vascularization. Nanostructured membranes of (MMA)1-co-(HEMA)1/(MA)3-co-(HEA)2 loaded with 5% wt of SiO2-nanoparticles (HOOC-Si-Membrane) were doped with zinc (Zn-HOOC-Si-Membrane) or doxycycline (Dox-HOOC-Si-Membrane). Critical bone defects were effectuated on six New Zealand-bred rabbit skulls and covered with the membranes. After six weeks, the bone architecture was evaluated with micro computed tomography. Three histological analyses were utilized to analyse bone regeneration, including von Kossa silver nitrate, toluidine blue and fluorescence. All membrane-treated defects exhibited higher number of osteocytes and bone perimeter than the control group without the membrane. Zn-HOOC-Si-Membranes induced higher new bone and osteoid area than those treated with HOOC-Si-Membranes, and control group, respectively. Zn-HOOC-Si-Membranes and Dox-HOOC-Si-Membranes attained the lowest ratio M1 macrophages/M2 macrophages. Dox-HOOC-Si-Membranes caused the lowest number of osteoclasts, and bone density. At the trabecular new bone, Zn-HOOC-Si-Membranes produced the highest angiogenesis, bone thickness, connectivity, junctions and branches. Zn-HOOC-Si-Membranes enhanced biological activity, attained a balanced remodeling, and achieved the greatest regenerative efficiency after osteogenesis and angiogenesis assessments. The bone-integrated Zn-HOOC-Si-Membranes can be considered as bioactive modulators provoking a M2 macrophages (pro-healing cells) increase, being a potential biomaterial for promoting bone repair.

A cationitrile sequence encodes mild poly(ionic liquid) crosslinking for advanced composite membranes

A new cation–methylene–nitrile functionality sequence of repeating poly(ionic liquid) units encodes unprecedented polymer crosslinking and nanostructured membranes displaying exceptional stability and solar-thermal desalination performance.