Microphase Diffusion-Controlled Interfacial Polymerization for an Ultrahigh Permeability Nanofiltration Membrane

The key to improving nanofiltration membrane permeance is reducing its thickness while maintaining high rejection. Herein, a 25 nm thick ultrathin polyamide layer was prepared by a microphase diffusion-controlled interfacial polymerization (MDC-IP) of poly­(ethyleneimine) and trimesoyl chloride, which is much thinner than the conventional interfacial polymerization (CIP) polyamide layer. A new formation mechanism for such an ultrathin layer is presented, which included a microphase interfacial reaction and eliminated loose layers due to the confinement of microphase diffusion and the termination of stepwise diffusion. Moreover, the polyamide layer was post-cross-linked to form a stable dual-cross-linked interwoven structure. Such a membrane showed an ultrahigh permeance of 1246 kg/(m² h MPa), which was 23 times that of CIP membranes. MDC-IP could efficiently control the microinterface between two immiscible phases, which provided a facile way to regulate the membrane at nanoscale

Nanoconfined Zeolitic Imidazolate Framework Membranes with Composite Layers of Nearly Zero Thickness

The key to preparing dense composite membranes is reducing the thickness of the composite layer with stable separation performance. Herein, we report a nanoconfined composite membrane prepared by in situ growth of Zeolitic Imidazolate Framework (ZIF) nanocrystals in the nanoporous layer of the substrate via a fine-tuning contra-diffusion method. The thickness of the composite layer on the membrane surface was nearly zero. The formed ZIF nanoconfined composite membranes showed state-of-art flux and high stability in removing dyes from water. This new strategy is expected to offer great opportunities for the potential practical application of polymer-supported metal–organic framework (MOF) composite membranes

One-Step Transformation from Hierarchical-Structured Superhydrophilic NF Membrane into Superhydrophobic OSN Membrane with Improved Antifouling Effect

The hierarchical-structured superhydrophilic poly­(ethylenimine)/poly­(acrylic acid) (PEI/PAA)calcium silicate hydrate (CSH) multilayered membranes (PEI/PAA-CSH)_<i>n</i> were prepared as aqueous nanofiltration (NF) membrane, and then they were transformed into superhydrophobic organic solvent nanofiltration (OSN) membranes by one-step modification of trimethylperfluorinatedsilane (PFTS). Investigation on surface structures and properties of these multilayered membranes (PEI/PAA-CSH)_<i>n</i> indicated that the hierarchical-structured (PEI/PAA-CSH)_<i>n</i> multilayered membrane produced by in situ incorporation of CSH aggregates into PEI/PAA multilayers facilitated its one-step transformation from superhydrophilicity into superhydrophobicity. Both of the superwetting membranes showed better nanofiltration performances for retention of dyes of water and ethanol solution, respectively. Moreover, the long-term performance and antifouling behaviors, investigated by retention of methyl blue (MB), bovine serum albumin (BSA), and humic acid (HA) aqueous water solution and nonaqueous ethanol solution indicated that both of the superhydrophilic and superhydrophobic membrane showed higher stability and excellent antifouling property

Low-Temperature Synthesis of Anatase TiO_{2 - Figure 4} Nanoparticles with Tunable Surface Charges for Enhancing Photocatalytic Activity

<p>Zeta potential of pure TiO₂, PEI-TiO₂ (10%) and PSS-TiO₂ (10%) as a function of pH (a); zeta potential of PEI (1.0 mg/mL) solution as a function of pH (b); Particle size of the TiO₂, PEI-TiO₂ and PSS-TiO₂ nanoparticles at different pH (c); Transmittance changes of TiO₂ (pH 3), PEI-TiO₂ (pH 5) and PSS-TiO₂ (pH 11) suspensions over time (d).</p

The elemental amounts of TiO₂, PEI-TiO₂ (10%) and PSS-TiO₂ (10%) nanoparticles.

<p>The elemental amounts of TiO₂, PEI-TiO₂ (10%) and PSS-TiO₂ (10%) nanoparticles.</p

Seizure Control of Current Shunt on Rats with Temporal Lobe Epilepsy and Neocortical Epilepsy

<div><p>Purpose</p><p>To examine the effects of current shunt on rats with temporal lobe epilepsy and neocortex epilepsy.</p><p>Experimental Design</p><p>A kainic acid (KA)-induced model of temporal lobe seizure and a penicillin-induced model of neocortical partial seizure were used in this study. Rats of each model were randomly allocated into two groups: control and model groups. The model group was further divided into the KA or penicillin group, sham conduction group and conduction group. The current shunt was realized through the implantation of a customized conduction electrode. After surgery, electroencephalogram (EEG) was recorded for two hours for each rat under anesthesia. Subsequently, the rats were video monitored for 72 h to detect the occurrence of behavioral seizures upon awakening. The average number and duration of seizures on EEG and the number of behavioral seizures were measured.</p><p>Results</p><p>In KA model, the number of total EEG seizures in conduction group (9.57±2.46) was significantly less than that in sham conduction group (15.13±3.45) (<i>p</i><0.01). The duration of EEG seizures in conduction group (26.13±7.81 s) was significantly shorter than that in sham conduction group (34.17±7.25 s) (<i>p</i> = 0.001). A significant reduction of behavioral seizures was observed in the conduction group compared with KA (p = 0.000) and sham conduction groups (p = 0.000). In penicillin model, there was a 61% reduction in total EEG seizures in conduction group compared with sham conduction group (p<0.01), and the duration of EEG seizures in conduction group (6.29±2.64 s) was significantly shorter than that in the sham conduction group (12.07±3.81 s) (p = 0.002). A significant reduction of behavioral seizures was observed in conduction group compared with penicillin (p<0.01) and sham conduction groups (p<0.01).</p><p>Conclusion</p><p>Current shunt effectively reduces the onset and severity of seizures. Current shunt therapy could be an effective alternative minimally invasive approach for temporal lobe epilepsy and neocortex epilepsy.</p></div

EDX spectra of (a) TiO₂, (b) PEI-TiO₂ (10%) and (c) PSS-TiO₂ (10%).

<p>EDX spectra of (a) TiO₂, (b) PEI-TiO₂ (10%) and (c) PSS-TiO₂ (10%).</p

The variations of zeta potentials of PEI-TiO₂ and PSS-TiO₂ nanoparticles with concentration of polyelectrolytes (pH of PEI-TiO₂ and PSS-TiO₂ was 5 and 11, respectively).

<p>The variations of zeta potentials of PEI-TiO₂ and PSS-TiO₂ nanoparticles with concentration of polyelectrolytes (pH of PEI-TiO₂ and PSS-TiO₂ was 5 and 11, respectively).</p

UV-vis diffuses reflectance spectra of TiO₂, PEI-TiO₂ and PSS-TiO₂ photocatalysts.

<p>UV-vis diffuses reflectance spectra of TiO₂, PEI-TiO₂ and PSS-TiO₂ photocatalysts.</p

Band edge (<i>λg</i>) and band gap energy (<i>E_g</i>) of TiO₂, PEI-TiO₂ and PSS-TiO₂ photocatalysts.

<p>Band edge (<i>λg</i>) and band gap energy (<i>E_g</i>) of TiO₂, PEI-TiO₂ and PSS-TiO₂ photocatalysts.</p