Ultra-Thin Electro-Spun PAN Nanofiber Membrane for High-Efficient Inhalable PM2.5 Particles Filtration

2017 ◽  
Vol 46 ◽  
pp. 73-81 ◽  
Author(s):  
Shi Su ◽  
Jiang Ling Li ◽  
Lei Zhou ◽  
Shu Wan ◽  
Heng Chang Bi ◽  
...  

In this work, we introduce a synthesis method for a nanofiber membrane made of polyacrylonitrile and verify its filtration ability with micron-size particles. The polyacrylonitrile nanofiber membrane was produced by electro-spun technique with a thickness less than 0.2 mm. The filtration experimental result from micron-size particle penetration proved that after 60-min deposition, the polyacrylonitrile nanofiber membrane successfully filtrated ~99% micron-size particles in solution. We found that uniform morphology, consistent nanofiber diameter without disordered beads will lead to a better filtration performance. This finding will provide a low-cost, environmental-friendly and straightforward filtration approach for future PM2.5 elimination in an aqueous and harsh environment.

2021 ◽  
Author(s):  
Yanran Lu ◽  
Wen Zhang ◽  
Mei Wang ◽  
Hua Zhang ◽  
Jiahui Li ◽  
...  

Abstract The adsorption is widely used to remove dyes from wastewater because of its low cost, simple preparation, and environmental friendliness. However, the existing adsorbents suffer from difficult recycling, inconvenient use, and low regeneration rate. In this study, polyacrylonitrile (PAN) and graphene oxide (GO) was mixed for electrospinning GO/PAN nanofiber membrane and then chitosan (CS) was grafted to obtain CS-GO/PAN nanofiber membrane. CS-GO/PAN membrane were characterized with FE-SEM, EDX, FT-IR and, WCA. The effects of membrane types, dosage, solution pH on the removal of dye sunset yellow (SY) were systematically investigated. The results showed that more than 80% of SY were removed within 15 min at pH 2 using 100 mg CS-GO/PAN membrane. Adsorption kinetic data were fitted well with the pseudo-second-order model and adsorption equilibrium achieved within 240 min. The isotherm study followed the Langmuir model with the actual maximum adsorption capacity of 211.54 mg/g. After 5 adsorption-desorption cycles, the adsorption efficiency and the desorption efficiency of CS-GO/PAN were over 90% and 93%, respectively. Moreover, the membrane recovered easily from the water while its integrity was still maintained. The CS-GO/PAN membrane demonstrates the virtue of high adsorption capacity, easy operation, and good reusability, which could be considered as a promising material for adsorbing dyes in wastewater.


2020 ◽  
Vol 18 (1) ◽  
pp. 1148-1166
Author(s):  
Ganjar Fadillah ◽  
Septian Perwira Yudha ◽  
Suresh Sagadevan ◽  
Is Fatimah ◽  
Oki Muraza

AbstractPhysical and chemical methods have been developed for water and wastewater treatments. Adsorption is an attractive method due to its simplicity and low cost, and it has been widely employed in industrial treatment. In advanced schemes, chemical oxidation and photocatalytic oxidation have been recognized as effective methods for wastewater-containing organic compounds. The use of magnetic iron oxide in these methods has received much attention. Magnetic iron oxide nanocomposite adsorbents have been recognized as favorable materials due to their stability, high adsorption capacities, and recoverability, compared to conventional sorbents. Magnetic iron oxide nanocomposites have also been reported to be effective in photocatalytic and chemical oxidation processes. The current review has presented recent developments in techniques using magnetic iron oxide nanocomposites for water treatment applications. The review highlights the synthesis method and compares modifications for adsorbent, photocatalytic oxidation, and chemical oxidation processes. Future prospects for the use of nanocomposites have been presented.


2009 ◽  
Vol 16 (03) ◽  
pp. 381-386 ◽  
Author(s):  
J. B. CHU ◽  
H. B. ZHU ◽  
Z. A. WANG ◽  
Z. Q. BIAN ◽  
Z. SUN ◽  
...  

Single-phase CuInSe 2 films were grown by high vapor selenization of CuIn alloy precursors within a partially closed graphite box. The CuIn precursors were prepared using Cu x In y alloy targets with different composition rates under low vacuum level by a homemade sputtering system. The Cu and In composition rates of the used targets are 11:9, 10:10, and 9:11, respectively. The metallic precursor films were selenized using a two-step temperature profile, i.e. at 250°C and 400–500°C, respectively. The influence of the temperature at the second selenization step on the quality of the CIS absorbing layers was investigated. The CIS films were characterized by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. The deposited CIS absorbers selenized at a high temperature of 500°C for 30 min exhibited a single-phase chalcopyrite structure with a preferential orientation in the (112) direction. These layers display uniform, large, and densely packed crystals with a grain size of about 3–5 μm. Cadmium sulfide buffer layer was manufactured by chemical bath deposition method. Bilayers ZnO / ZnO : Al were prepared by RF magnetron sputtering deposition. CIS solar cells with an efficiency of about 6.5% were produced without antireflective films. The method to fabricate CIS solar cells by a combination of the low vacuum sputtering deposition and the graphite box selenization process has provided a simple control process and shown a promising potential for developing high efficient and low-cost CuInSe 2 solar cells.


2012 ◽  
Vol 236-237 ◽  
pp. 839-843
Author(s):  
Xiao Meng Cui ◽  
Guang Xue Chen ◽  
Huan Mei Wang ◽  
Lin Lin Chen

In this study we present a new framework to assess line micro quality of multicolor prints adapted to a low-cost image quality analysis system based on common flatbed scanner. The contribution elements including quality metrics, measurement principle, applying methods and detection instrument, which were complemented and sorted in terms of ISO 13660 standard, were described and a case experiment was conducted to survey the output performance of both inkjet printer and xerographic printer, two most popular digital printing technologies. Their qualities were compared in details rendering angle such as width and straightness of line, raggedness and blurriness in line edges, as well as darkness and contrast in color. The results verify the efficiency and shortcomings of the framework. Meanwhile, the metric values let us take an investigation in the character of each digital printing technology in micron size.


2021 ◽  
Vol 15 (2) ◽  
pp. 128-135
Author(s):  
Thaís Luiz ◽  
Fabio Nakagomi ◽  
Reny Renzetti ◽  
Guilherme Siqueira

The microwave assisted combustion synthesis (MACS) as a new, quick and low cost synthesis method was used for preparation of niobium pentoxide (Nb2O5) powders. The present paper investigated the effect of reactant concentrations (ammonium niobium oxalate, urea and ammonium nitrate) on the characteristics of Nb2O5 nanoparticles. Three samples were synthesized with stoichiometric ratio between the fuel and oxidant (C1), excess of oxidant (C2) and excess of fuel (C3). In all samples, Nb2O5 crystalline nanoparticles with irregular morphology were detected. The synthesis of nanoparticles with smaller diameter in the C2 and C3 samples was confirmed by greater values of band gap energy measured through UV-Visible diffuse reflectance spectroscopy (indicating quantum confinement) and by the Rietveld refinement of X-ray diffraction patterns. The results showed that the amounts of oxidant and fuel can change synthesis temperature, influencing the final characteristics of the particles, such as size and existent phases. In these cases the excess of oxidant and fuel in the C2 and C3 samples, respectively, decreases the average synthesis temperature and decelerates the particle growth and the formation of the monoclinic phase.


Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 963
Author(s):  
Ai Hsin ◽  
Su-Chun How ◽  
Steven S.-S. Wang ◽  
Chien Wei Ooi ◽  
Chen-Yaw Chiu ◽  
...  

The polyacrylonitrile (PAN) nanofiber membrane was prepared by the electrospinning technique. The nitrile group on the PAN nanofiber surface was oxidized to carboxyl group by alkaline hydrolysis. The carboxylic group on the membrane surface was then converted to dye affinity membrane through reaction with ethylenediamine (EDA) and Cibacron Blue F3GA, sequentially. The adsorption characteristics of lysozyme onto the dye ligand affinity nanofiber membrane (namely P-EDA-Dye) were investigated under various conditions (e.g., adsorption pH, EDA coupling concentration, lysozyme concentration, ionic strength, and temperature). Optimum experimental parameters were determined to be pH 7.5, a coupling concentration of EDA 40 μmol/mL, and an immobilization density of dye 267.19 mg/g membrane. To understand the mechanism of adsorption and possible rate controlling steps, a pseudo first-order, a pseudo second-order, and the Elovich models were first used to describe the experimental kinetic data. Equilibrium isotherms for the adsorption of lysozyme onto P-EDA-Dye nanofiber membrane were determined experimentally in this work. Our kinetic analysis on the adsorption of lysozyme onto P-EDA-Dye nanofiber membranes revealed that the pseudo second-order rate equation was favorable. The experimental data were satisfactorily fitted by the Langmuir isotherm model, and the thermodynamic parameters including the free energy change, enthalpy change, and entropy change of adsorption were also determined accordingly. Our results indicated that the free energy change had a negative value, suggesting that the adsorption process occurred spontaneously. Moreover, after five cycles of reuse, P-EDA-Dye nanofiber membranes still showed promising efficiency of lysozyme adsorption.


2020 ◽  
Author(s):  
DongHui Li ◽  
◽  
Jie Sun ◽  
Rong Ma ◽  
JinJia Wei ◽  
...  

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhangli Liu ◽  
Jiaxing Xu ◽  
Min Xu ◽  
Caifeng Huang ◽  
Ruzhu Wang ◽  
...  

AbstractThermally driven water-based sorption refrigeration is considered a promising strategy to realize near-zero-carbon cooling applications by addressing the urgent global climate challenge caused by conventional chlorofluorocarbon (CFC) refrigerants. However, developing cost-effective and high-performance water-sorption porous materials driven by low-temperature thermal energy is still a significant challenge. Here, we propose a zeolite-like aluminophosphate with SFO topology (EMM-8) for water-sorption-driven refrigeration. The EMM-8 is characterized by 12-membered ring channels with large accessible pore volume and exhibits high water uptake of 0.28 g·g−1 at P/P0 = 0.2, low-temperature regeneration of 65 °C, fast adsorption kinetics, remarkable hydrothermal stability, and scalable fabrication. Importantly, the water-sorption-based chiller with EMM-8 shows the potential of achieving a record coefficient of performance (COP) of 0.85 at an ultralow-driven temperature of 63 °C. The working performance makes EMM-8 a practical alternative to realize high-efficient ultra-low-temperature-driven refrigeration.


2020 ◽  
Author(s):  
Luqman Hakim Mohd Azmi ◽  
Daryl R. Williams ◽  
Bradley P. Ladewig

<div><b>Abstract</b></div><div>A new synthesis method was developed to prepare an aluminum-based metal organic framework (MIL-96) with a larger particle size and different crystal habits. A low cost and water-soluble polymer, hydrolyzed polyacrylamide (HPAM), was added in varying quantities into the synthesis reaction to achieve >200% particle size enlargement with controlled crystal morphology. The modified adsorbent, MIL-96-RHPAM2, was systematically characterized by SEM, XRD, FTIR, BET and TGA-MS. Using activated carbon (AC) as a reference adsorbent, the effectiveness of MIL-96-RHPAM2 for perfluorooctanoic acid (PFOA) removal from water was examined. The study confirms stable morphology of hydrated MIL-96-RHPAM2 particles as well as a superior PFOA adsorption capacity (340 mg/g) despite its lower surface area, relative to standard MIL-96. MIL-96-RHPAM2 suffers from slow adsorption kinetics as the modification significantly blocks pore access. The strong adsorption of PFOA by MIL-96-RHPAM2 was associated with the formation of electrostatic bonds between the anionic carboxylate of PFOA and the amine functionality present in the HPAM backbone. Thus, the strongly held PFOA molecules in the pores of MIL-96-RHPAM2 were not easily desorbed even after eluted with a high ionic strength solvent (500 mM NaCl). Nevertheless, this simple HPAM addition strategy can still chart promising pathways to impart judicious control over adsorbent particle size and crystal shapes while the introduction of amine functionality onto the surface chemistry is simultaneously useful for enhanced PFOA removal from contaminated aqueous systems.<br></div>


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