Tailoring Mechanically Robust Poly(m-phenylene isophthalamide) Nanofiber/nets for Ultrathin High-Efficiency Air Filter

Zhang

et al. 2019

Adv Funct Materials

Self Cite

191

142

Particulate matter (PM) pollution has posed a huge health and economic burden worldwide. Most existing air filters used to remove PMs are structurally monotonous, cumbersome, and inevitably suffer from the compromise between removal efficiency and air permeability; developing an advanced air filter that can overcome these limitations is of significance but highly challenging. Herein, a novel strategy to create ultrathin, high-performance air filters based on fluffy dual-network structured polyacrylonitrile nanofiber/ nets, via a humidity-induced electrospinning/netting technique, is reported. By tailoring the ejection and phase separation of the charged liquids, this approach causes 2D ultrafine (≈20 nm) nanonets tightly bonded with fluffy pseudo-3D nanofiber scaffolds to form dual-network structures, with controllable pore size and stacking density on a large scale. The resultant nanofiber/ net filters possess the integrated features of small pore size (<300 nm), high porosity (93.9%), low packing density, combined with desirable surface chemistry (4.3-D dipole moment), resulting in high-efficiency PM 0.3 removal (>99.99%), low air resistance (only <0.11% of atmosphere pressure), and promising long-term PM 2.5 purification. The synthesis of such materials may provide new insights into the design and development of high-performance filtration and separation materials for various applications.

Section: Introductionmentioning

confidence: 99%

A Fluffy Dual‐Network Structured Nanofiber/Net Filter Enables High‐Efficiency Air Filtration

Zhang

et al. 2019

Adv Funct Materials

Self Cite

191

142

Polymer Engineering & Sci

“…Figure illustrates the FE‐SEM images of NFNM obtained under optimum conditions with novel 3D web‐like nano‐nets comprising interlinked nanowires. Previous studies showed that the nano‐net has a positive effect on mechanical properties of fibrous webs via “nets bonding” . In this research, the goal is to get optimum value of CTAB concentration for NFNM characteristic improvement.…”

Section: Resultsmentioning

confidence: 98%

“…Electrospinning/netting (ESN) is an advanced and novel electro‐hydrodynamic technique in the one‐step fabrication of “nano‐nets” with ultrathin nanowire (diameter: ∼30 nm), smaller pore size and large quantities . Researchers have reported that this unique structure could improve the membranes mechanical properties .…”

Section: Introductionmentioning

confidence: 99%

Modeling and optimization of waterproof‐breathable thermo‐regulating core‐shell nanofiber/net structured membrane for protective clothing applications

Rahimi

Mokhtari

2018

The mechanical and functional properties of thermo‐regulating hexadecane‐polyurethane (HD‐PU) nanofiber/net membrane (NFNM) with potential application in protective clothing were modeled and optimized. The optimum conditions for fabrication of the HD‐PU NFNM were obtained using response surface methodology (RSM). Central composite design (CCD) matrix was employed to develop predictive regression models along with optimize and investigate the effects of important parameters such as PU and surfactant concentrations, and co‐electrospinning time, on the responses. Mechanical and functional properties of protective membranes including strength, elongation, water vapor transmission rate (WVTR), hydrostatic pressure, air permeability, and enthalpy of fusion were optimized as responses. As a result, higher NFNM strength was observed by increasing PU and surfactant concentrations. Thermal regulating efficiency (TRE) or HD loading amount for optimized NFNM was calculated using the results of RSM and experimental data, and it was obtained as 28% and 24%, respectively. Therefore, remarkable agreement with errors lower than 12% between predicted and experimental values was achieved. According to our findings, NFNM characteristics can be improved under controlled conditions and RSM is an efficient method to predict and optimize these conditions. POLYM. ENG. SCI., 58:1756–1765, 2018. © 2018 Society of Plastics Engineers

Part & Part Syst Charact

“…In our view, the nanofiber web's fracture mechanism can be divided into four phases represented by elongation/slippage, breakage of weaker part/slippage, further fracture, and maximum fracture leading to catastrophic failure of the structure. At phase one, nanofibers tend to deform under small stress: linear elongation and slow slippage of nanofibers resulting in the rapid increase in extension and linear elastic behavior . At phase two, tensile stress continually increases, and weak nanofibers show partial break‐up and continue slippage, which corresponds to the relatively slow increase of tensile strain in the stress–stain curve .…”

Section: Resultsmentioning

confidence: 99%

Visible Light Photocatalytic Functional TiO₂/PVDF Nanofibers for Dye Pollutant Degradation

Lou

Wang

Lee

et al. 2019

contaminated water becomes an environmental hazard.Functional photocatalytic nanofiber webs [6,7] are promising environmentally friendly candidates for the photodegradation of organic pollutants, such as dyes and pigments. Nanofibers have high specific morphology, [8] small diameter [9] and small pore size, [10] and customizable physicochemical characteristics, [11] which make them excellent candidates in wastewater treatment, [12] biomedical applications, [13][14][15] protein purification, [16] and air filtration. [17] Poly(vinylidene fluoride) (PVDF) [18] is a commonly used hydrophobic polymer for wastewater treatment, due to its excellent thermal stability, mechanical stability, chemical resistance, and selective permeability. However, interception effect (meaning large particles would be intercepted by small pore size nanofiber webs), the major ultrafiltration mechanism for unfunctionalized PVDF nanofiber webs, [19] limits their applications because of their low filtration efficiency and poor functionality. The addition of nanoparticles could improve the photocatalytic properties, [20] mechanical properties, [21] hydrophobicity, [22,23] and other functional performances of nanofiber webs. [19][20][21][22][23] Moreover, physical modification methods (addition of functional nanoparticles) have proved to be simpler and more effective than chemical modification methods. [24] Commonly used nanoparticles include titanium dioxide (anatase TiO 2 ), [25] zinc oxide (ZnO), [26] aluminum oxide (Al 2 O 3 ), [27] magnetite (Fe 3 O 4 ), [28] graphite oxide (GO), [29] multiwalled carbon nanotubes (MWCNTs), [30] and polymeric nanoparticles. [31] Polymeric nanoparticles, including nanospheres and nanocapsules, are formed by a polymeric matrix and mainly used for drug delivery, where the molecules are absorbed in or on the matrix, for example, encapsulation of insulin in poly(lactic-co-glycolic acid) nanoparticles. [32] Among these nanoparticles, anatase titanium dioxide is the most widely used catalyst for water treatment because of low cost, stability in water, and high photocatalytic property. [19][20][21] The addition of TiO 2 in nanofiber webs can greatly improve the degradation rate of organic pigments/dyes pollutants, [19] antibacterial properties, [20] and other performances (antifouling property, wettability). [20,21,23] Electrospinning is a popular and simple method to produce functional nanofiber webs among all existing nanofiber webs technologies, such as melt spinning, solution spinning, andThe photodegradation of poly(vinylidene fluoride) (PVDF)/titanium oxide (TiO 2 ) nanofibers under visible light is described, something that has not been previously reported in the literature. Visible light photocatalytic electrospun PVDF/TiO 2 nanofiber webs with anatase TiO 2 concentration varying from 0% to 20% (0%, 1%, 3%, 5%, 10%, and 20%) are produced, and their ability to degrade a toxic pollutant, Rhodamine B (RhB), is studied. Photodegradation study using UV-vis spectroscopy on PVDF/TiO 2 nanofiber webs (with TiO 2 con...