Facile transformation of soot nanoparticles into nanoporous fibers via single-step electrospinning

Abstract

A facile technique to transform candle soots into nanoporous fibers via electrospinning of mixed solution of candle soots and polyvinylidene fluoride (PVDF) has been demonstrated for the first time. Due to insolubility of soot nanoparticles and good solubility of PVDF polymer in DMF/acetone solvents, the soot molecules are heterogeneously dispersed in the mixed solutions. The selection of an appropriate polymer concentration resulted in a good dispersion of the low-density soot nanoparticles which can be held for electrospinning. The electrospinning experiment shows that soot nanoparticles can be smoothly bonded with PVDF molecules to form nanoporous fibers. The unique superhydrophobic and superoleophilic properties of the as-prepared electrospun fibrous membrane were demonstrated by subjecting it to various aqueous liquids and oils. This work provides a simple way to transform low-density nanoparticles into high-performance nanoporous nanofibers, which should broaden the applications of electrospinning.

Facile Preparation of Superhydrophobic Membrane Inspired by Chinese Traditional Hand-Stretched Noodles

“…A piece of metal sheet was placed above the center flame of a burning paraffin candle ( Figure 1A) and was adjusted accordingly to obtain superhydrophobic soot nanoparticles ( Figure 1B) [23,24]. The soot particles prepared in this way were found to have an average particle size less than 50 nm, as reported in our previous work [25] and summarized in a very recent review paper [26]. A piece of paper with a square-shaped opening was placed on the sheet of metal that was covered with the soot ( Figure 1C) and used as a collector for the electrospinning experiment.…”

Candle Soot-Based Electrosprayed Superhydrophobic Coatings for Self-Cleaning, Anti-Corrosion and Oil/Water Separation

“…Candles and substrates including glass slides, stainless steel and copper meshes, cotton fabrics, printing paper, iron sheets, wood panels, and cobblestones were purchased from local supermarkets. The superhydrophobic CS was collected from the middle zone of candle flame as described previously [ 18 , 28 ]. Specifically, by placing a stainless steel plate above the outer flame of the burning candle for 1 min, a thick layer of CS particles was obtained on the plate, which could be further scraped and transferred for use.…”

“…Fresh CS collected from the inner flame is superhydrophobic (water contact angle, WCA ≥ 150°) [ 4 ], but pristine CS is fragile and oxidation during aging causes the soot to become hydrophilic [ 5 ]. To obviate these problems, researchers have proposed numerous approaches that can be classified into the following three major categories: (1) substrate pretreatment before CS deposition, either through coating polydimethylsiloxane (PDMS) mixtures [ 6 , 7 , 8 ] or paraffin wax [ 9 ] on the raw substrate, or making the substrate much rougher (e.g., via electrodeposition [ 10 ] or other methods [ 11 , 12 ]); (2) reinforcement after CS deposition, mainly via covering the CS layer with PDMS mixtures [ 13 , 14 ] or some specific polymer solutions [ 15 ]; and (3) mixing CS with polymer for solution deposition of superhydrophobic coatings [ 16 , 17 , 18 ].…”

Candle soot nanoparticle embedded nanofibrous membrane for separation of miscible and immiscible oil/water mixtures

“…However, these materials have not been evaluated as oil/water separation absorbents. The soot‐embedded polyvinylidene fluoride (PVDF) nanofibrous membrane, [ 47 ] CS‐coated nickel foam, [ 48 ] copper mesh, [ 10 ] melamine sponge, [ 49 ] and egg carton materials [ 50 ] are examples. However, CS particles have fragile adhesion to substrate materials in most cases, which must be addressed to make them robust and reusable for oil/water separation.…”