Dispersions of hydrophilic fumed silica are investigated in a range polar organic media. The forms stable, low-viscosity sols exhibiting shear thickening behavior host liquids, including ethylene glycol and its oligomers short-chain alcohols, such as n-propanol. In contrast, the flocculates into colloidal gels other glycols with methyl end-caps longer-chain alcohols. We suggest that there is causal relationship between hydrogen-bonding ability liquid microstructure observed. strongly...

The threat associated with chemical warfare agents (CWAs) motivates the development of new materials to provide enhanced protection a reduced burden. Metal-organic frame-works (MOFs) have recently been shown as highly effective catalysts for detoxifying CWAs, but challenges still remain integrating MOFs into functional filter media and/or protective garments. Herein, we report series MOF-nanofiber kebab structures fast degradation CWAs. We found TiO2 coatings deposited via atomic layer...

Rapid room-temperature synthesis of metal–organic frameworks (MOFs) is highly desired for industrial implementation and commercialization. Here we find that a (Zn,Cu) hydroxy double salt (HDS) intermediate formed in situ from ZnO particles or thin films enables rapid growth (<1 min) HKUST-1 (Cu3(BTC)2) at room temperature. The space-time-yield reaches >3 × 104 kg·m–3·d–1, least 1 order magnitude greater than any prior report. high anion exchange rate nitrate HDS drives the ultrafast MOF...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation H. J. Walls, S. Brett Caines, Angelica M. Sanchez, Saad A. Khan; Yield stress wall slip phenomena in colloidal silica gels. Rheol. 1 July 2003; 47 (4): 847–868. https://doi.org/10.1122/1.1574023 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex...

While metal‐organic frameworks (MOFs) show great potential for gas adsorption and storage, their powder form limits deployment opportunities. Integration of MOFs on polymeric fibrous scaffolds will enable new applications in adsorption, membrane separation, catalysis, toxic sensing. Here, we demonstrate a synthesis route growing materials that achieves high MOF loadings, large surface areas adsorptive capacities. We find nanoscale coating Al 2 O 3 formed by atomic layer deposition (ALD) the...

Fiber@ALD@MOF structures fabricated <italic>via</italic> ALD and layer-by-layer MOF synthesis show good conformality high adsorption capacity.

Chemically functional microporous metal–organic framework (MOF) crystals are attractive for filtration and gas storage applications, recent results show that they can be immobilized on high surface area substrates, such as fiber mats. However, fundamental knowledge is still lacking regarding initial key reaction steps in thin film MOF nucleation growth. We find inorganic layers formed by atomic layer deposition (ALD) promote solvothermal growth of copper benzenetricarboxylate (Cu-BTC)...

Abstract The threat associated with chemical warfare agents (CWAs) motivates the development of new materials to provide enhanced protection a reduced burden. Metal–organic frame‐works (MOFs) have recently been shown as highly effective catalysts for detoxifying CWAs, but challenges still remain integrating MOFs into functional filter media and/or protective garments. Herein, we report series MOF–nanofiber kebab structures fast degradation CWAs. We found TiO 2 coatings deposited via atomic...

Abstract The use of nanocomposites constitutes a versatile and robust approach in the development novel electrolytes with tailored electrochemical mechanical characteristics. In this study, we examine morphology, rheology, ion‐transport properties two types nanocomposite electrolyte gels, one consisting branched silica nanoparticles other composed hectorite clay. first system hydrophobic (fumed) silica, oligomers poly(ethylene oxide) (PEO), lithium salt, acts as passive filler does not...

The ion-transport properties of composite electrolytes composed oligomers poly(ethylene glycol) dimethyl ether, hydrophobic fumed silica, and (LiTFSI) are investigated using nuclear magnetic resonance (NMR), electrophoretic NMR (ENMR), ac impedance spectroscopy, rheology. effects silica salt concentration on ionic conductivity, diffusivity ions oligomers, lithium transference number examined at 30°C. forms a self- supporting network with large pores such that the network, regardless...

Airborne viruses represent a potentially significant health threat. However, only recently have researchers begun to characterize the size and infectivity of viral bioaerosols in nanoscale range. There are limitations generation test aerosols ability sample with acceptable efficiency. Reported here is use laminar-flow water condensation method efficiently sizes well below 100 nm. We used MS2 bacteriophage provide an aerosol particles from 300 nm down 45 for sampling by both all-glass...

The lithium ion transference number and anion were determined for composite polymer electrolytes based on ethylene oxide hydrophobic fumed silica. These numbers measured using electrophoretic nuclear magnetic resonance (ENMR), which essentially is a rapid Hittorf method. We demonstrated the validity power of ENMR technique by independently measuring both single sample showed that (within experimental error). Measurement typically easier more accurate than measurement . powerful...

Encapsulating and functionalizing polymer nanofibers can improve the polymers chemical resistance surface reactivity, enabling new applications including biosensing, flexible electronics, gas filtration, separations. Polymer fiber functionalization typically involves energy intensive wet treatments and/or plasma exposure. Recent results show low temperature atomic layer deposition (ALD) to be a viable means coat with uniform conformal inorganic hybrid organic–inorganic layers. For this...

Sampling for culturable (e.g., viable) aerosolized microbes (bioaerosols) is a useful means to provide information public health monitoring and studies. However, it challenging maintain microbe culturability when sampling at high flow rates (>12 L/min) extended periods of time (≥4 h). We developed first-generation, viable bioaerosol collection system (VBCS) utilizing temperature (T) relative humidity (RH)–conditioned filtration rate 25 L/min. A two-stage tube-in-shell Nafion™ exchange units...

A new method for integrating metal-organic frameworks (MOFs) on polymer fibers is developed based an oxide nucleation layer via atomic deposition (ALD). As G. N. Parsons and co-workers report in article 1400040, ALD coating enables uniform MOF coverage fibers, high loading, large BET surface area. NH3 breakthrough tests demonstrate adsorption capacity of the MOF-fiber mats toxic gas. The synthesis approach also generally applicable to a wide range MOFs. This work represents deployment MOFs...

Wearable devices, such as smartwatches integrating heart rate and activity sensors, have the potential to transform health monitoring by enabling continuous, near real-time data collection analytics. In this paper, we present a novel modular architecture for collecting end-to-end processing of high-resolution signals from wearable sensors. The system obtains minimally processed directly smartwatch further processes analyzes stream without transmitting it device vendor cloud. standalone...

We describe a prototype scalable viscometer aimed at facilitating rapid measurements of multiple samples. The device simultaneously measures the viscosity four samples in an array Couette cells. Each cell contains rotor with embedded permanent magnet that is driven by oscillating magnetic field generated two-axis Helmholtz coil. angular displacement rotors recorded charge-coupled camera. Image analysis determines amplitude and phase respect to coil's sinusoidal current. each sample...

Background Wearable physiological monitoring devices are promising tools for remote and early detection of potential health changes interest. The widespread adoption such an approach across communities over long periods time will require automated data platform collecting, processing, analyzing relevant information. Objective In this study, we explore prospective individual through collection, metrics extraction, anomaly analysis pipeline in free-living conditions a continuous period several...

Background Measuring heart rate variability (HRV) through wearable photoplethysmography sensors from smartwatches is gaining popularity for monitoring many health conditions. However, missing data caused by insufficient wear compliance or signal quality can degrade the performance of metrics algorithm calculations. Research needed on how to best account and assess accuracy derived sensors. Objective This study aimed evaluate influence HRV collected both at rest during activity in real-world...

<sec> <title>BACKGROUND</title> Wearable physiological monitoring devices are promising tools for remote and early detection of potential health changes interest. The widespread adoption such an approach across communities over long periods time will require automated data platform collecting, processing, analyzing relevant information. </sec> <title>OBJECTIVE</title> In this study, we explore prospective individual through collection, metrics extraction, anomaly analysis pipeline in...