Deposition of MOFs on Polydopamine-Modified Electrospun Polyvinyl Alcohol/Silica Nanofibers Mats for Chloramphenicol Adsorption in Water

Nanofiber mats produced by electrospinning, with the advantages of specific surface area, porosity and chemical tenability, are an ideal support material for deposition of metal[Formula: see text]organic framework (MOF) crystals. In this study, four types of MOFs (MIL-53(Al), ZIF-8, UiO-66-NH2 and NH2-MIL-125(Ti)) were deposited on polydopamine (PDA)-modified electrospun polyvinyl alcohol (PVA)/SiO2 organic[Formula: see text]inorganic hybrid nanofiber mats by bulky synthesis. Because of the formation of Si–O–C–O–Si bridges between PVA chains and silica network, electrospun PVA/SiO2 organic[Formula: see text]inorganic hybrid nanofiber mats are quite stable in water or organic solvents and at high temperature are suitable as supports for MOFs deposition. The PDA layer, which exhibits a powerful adhesive ability to attach foreign objects, can effectively improve growth of MOFs on the surface of PVA/SiO2 nanofiber mats. The obtained MOF composites combining the unique properties of electrospun nanofibers mats and MOFs particles become flexible and tailorable, greatly expanding the application range of MOFs materials. The synthesized MOF composites were used to adsorb chloramphenicol (CAP) in water. It was found that the four MOF composites could remove CAP from water effectively and MIL-53(Al) composite had the highest adsorption capacity due to the higher specific surface area.

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Synthesis of reduced graphene oxide/aluminum nanocomposites via chemical-mechanical processes

Journal of Composite Materials ◽

10.1177/0021998318760152 ◽

2018 ◽

Vol 52 (22) ◽

pp. 3015-3025 ◽

Cited By ~ 1

Author(s):

Daeyoung Kim ◽

Heon Kang ◽

Donghyun Bae ◽

Seungjin Nam ◽

Manuel Quevedo-Lopez ◽

...

Keyword(s):

Graphene Oxide ◽

Polyvinyl Alcohol ◽

Specific Surface ◽

Reduced Graphene Oxide ◽

Surface Area ◽

Specific Surface Area ◽

Aluminum Powder ◽

Mechanical Milling ◽

Uniform Dispersion ◽

Reduced Graphene

The present study employed a combination of solution-based synthesis and mechanical milling to develop reduced graphene oxide/aluminum composites, in order to achieve uniform dispersion of reduced graphene oxide and strong interfaces between reduced graphene oxide and aluminum. First, spherical aluminum powder was flattened via mechanical milling to afford a large specific surface area and many reaction sites for the graphene oxide. A hydrophilic surface was then created by coating the aluminum powder with polyvinyl alcohol. The polyvinyl alcohol-coated aluminum slurry was mixed with a graphene oxide suspension, thereby inducing a reaction between graphene oxide and polyvinyl alcohol via hydrogen bonding. After thermal reduction, the composite powder was further ball milled and hot-pressed at 500℃ to produce a reduced graphene oxide/aluminum composite. The dispersion of reduced graphene oxide in the composite, as well as the mechanical and thermal behaviors of the composite, improved with increased flattening and specific surface area of the starting aluminum powder.

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Measurement of vertical profiles of snow specific surface area with a 1 cm resolution using infrared reflectance: instrument description and validation

Journal of Glaciology ◽

10.3189/002214311795306664 ◽

2011 ◽

Vol 57 (201) ◽

pp. 17-29 ◽

Cited By ~ 81

Author(s):

L. Arnaud ◽

G. Picard ◽

N. Champollion ◽

F. Domine ◽

J.C. Gallet ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Incidence Angle ◽

Microwave Remote Sensing ◽

Theoretical Formulation ◽

Reflectance Measurement ◽

Application Range ◽

New Device ◽

Rapid Acquisition

AbstractThe specific surface area (SSA), defined as the surface area of ice per unit mass, is an important variable characterizing the complex microstructure of snow. Its application range covers the physical evolution of snow (metamorphism), photochemistry and optical and microwave remote sensing. This paper presents a new device, POSSSUM (Profiler Of Snow Specific Surface area Using SWIR reflectance Measurement), designed to allow the rapid acquisition of SSA profiles down to ∼20 m depth and with an effective vertical resolution of 10–20 mm. POSSSUM is based on the infrared (IR) reflectance technique: A laser diode operating at 1310 nm illuminates the snow at nadir incidence angle along the face of a drilled hole. The reflected radiance is measured at three zenith angles (20°, 40° and 60°) each for two azimuth angles (0° and 180°). A second laser operating at a shorter wavelength (635 nm), which is almost insensitive to SSA, allows the distance to the snow face to be estimated. The reflected IR radiance and the distance are combined to estimate bidirectional reflectances. These reflectances are converted into hemispherical reflectances and in turn into SSA using a theoretical formulation based on an asymptotic solution of the radiative transfer equation. The evaluation and validation of POSSSUM’s SSA measurements took place in spring 2009 in the French Alps. The new method was compared with the methane adsorption technique and DUFISSS, another well-validated instrument based on the IR technique. The overall measurement error is in the range 10–15%.

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Electrospun Nanofibers with High Specific Surface Area to Prepare Modified Electrodes for Electrochemiluminescence Detection of Azithromycin

Journal of Nanomaterials ◽

10.1155/2021/9961663 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Hao Cheng ◽

Xuenuan Li ◽

Tianhao Li ◽

Danfeng Qin ◽

Tingfan Tang ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Active Sites ◽

Raw Materials ◽

Modified Electrodes ◽

Electrospun Nanofibers ◽

High Sensitivity ◽

Specific Area ◽

High Specific Surface Area

Polyacrylonitrile (PAN) and (CH3COO)2Zn were used as raw materials, and carbon nanofibers (CNFs) with high specific surface area were successfully prepared by an electrospinning method. A new method of electrochemiluminescence detection of azithromycin was established by modifying the glassy carbon electrode (GCE). Under the optimal conditions, the electrochemical behavior and electrochemiluminescence behavior of the Ru(bpy)32+-AZM system on the modified electrode were investigated. Owing to the large specific area, more active sites, and promotion of electron transfer, the sensor exhibits high electrocatalytic activity, high sensitivity, a good linear relationship ranging from 8.0 × 10 − 8 to 1.0 × 10 − 4 mol/L, and a low detection limit ( 6.52 × 10 − 8 mol/L). In addition, the good recoveries indicate that the sensor was a promising device for the detection of azithromycin in real samples.

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The effect of polyvinyl alcohol on the nitrogen surface area and pore structure of soils

Soil Research ◽

10.1071/sr9670077 ◽

1967 ◽

Vol 5 (1) ◽

pp. 77 ◽

Cited By ~ 21

Author(s):

BG Williams ◽

DJ Greenland ◽

JP Quirk

Keyword(s):

Polyvinyl Alcohol ◽

Specific Surface ◽

Pore Structure ◽

Pore Size Distribution ◽

Pore Size ◽

Surface Area ◽

Specific Surface Area ◽

Clay Soil ◽

Adsorption Data ◽

Desorption Isotherms

Changes in the specific surface area and pore size distribution due to adsorption of polyvinyl alcohol (PVA) by aggregates of a clay soil have been determined from the desorption isotherms for nitrogen at -195�C. The specific surface area was reduced. The volume of pores less than 30 A wide decreased by an amount considerably in excess of the volume of PVA adsorbed. These results are interpreted in terms of 'peripheral pore occupation' by the polymer, preventing access of nitrogen molecules to pores and surfaces within domains. Adsorption data previously obtained also indicated limited penetration of domains by the polymer.

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Preparation and Characterization of Highly Porous Polyacrylonitrile Electrospun Nanofibers Using Lignin as Soft Template via Selective Chemical Dissolution Technique

Polymers ◽

10.3390/polym13223938 ◽

2021 ◽

Vol 13 (22) ◽

pp. 3938

Author(s):

Mohd Adib Tajuddin Ahmad ◽

Norizah Abdul Rahman

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Electrospun Nanofibers ◽

Soft Template ◽

Chemical Dissolution ◽

Electrospinning Technique ◽

Average Pore ◽

Selective Chemical ◽

Highly Porous

In this study, polyacrylonitrile (PAN) was mixed with a renewable polymer, lignin, to produce electrospun nanofibers by using an electrospinning technique. Lignin was utilized as a soft template that was removed from the nanofibers by using a selective dissolution technique to create porous PAN nanofibers. These nanofibers were characterized with Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), thermogravimetry analysis (TGA), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) to study their properties and morphology. The results showed that lignin can be homogeneously mixed into the PAN solution and successfully electrospun into nanofibers. FESEM results showed a strong relationship between the PAN: lignin ratio and the diameter of the electrospun fibers. Lignin was successfully removed from electrospun nanofibers by a selective chemical dissolution technique, which resulted in roughness and porousness on the surface of the nanofibers. Based on the BET result, the specific surface area of the PAN/lignin nanofibers was more than doubled following the removal of lignin compared to PAN nanofibers. The highest specific surface area of nanofibers after selective chemical dissolution was found at an 8:2 ratio of PAN/lignin, which was 32.42 m2g−1 with an average pore diameter of 5.02 nm. The diameter of electrospun nanofibers was also slightly reduced after selective chemical dissolution. Porous PAN nanofibers can be seen as the precursors to the production of highly porous carbon nanofibers.

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