Study oil/water separation property of PE foam and its improvement by <i>in situ</i> synthesis of zeolitic–imidazolate framework (ZIF‐8)

Freshwater resources are currently insufficient, and another form of freshwater resources, namely, ice, is very interesting except for the issue of how to use new materials for effective purification during the processing procedure. In this article, a new membrane material with multisize pore structure in the cross‐section and intact thin skin layer on the upper and lower surfaces was successfully prepared by adding porogen, filler and setting heating environment during the phase separation process. The membrane exhibits excellent axial deformability, and its elongation at break can reach to 160% strain. Meanwhile, they all show elastic deformation behavior in the range from −60 to 100°C. Even if high content of hydrophobic filler is compounded into these membranes, that is, 5.7 wt% carbon tube content, water contact angle of membrane's surface is only 72.5°, demonstrating obvious hydrophilicity. In addition, in the water purification process, the adsorption rate constant reached ideal value of 0.26 s−1, and the equilibrium adsorption capacity was about 2.8 g/g, showing fast and efficient water purification ability. In the mode of external heating source or the membrane's heat dissipation, these prepared membranes can melt the ice to obtain purified water and exhibit a controllable purification ability in this process.

Section: Introductionmentioning

confidence: 99%

Poly(ether‐block‐amide) membrane with deformability and adjustable surface hydrophilicity for water purification

Wang

Zhao

et al. 2021

“…The increase in offshore and onshore oil production and transportation in the world has become one of the leading causes of environmental disasters, with oil spills and leaks of organic pollutants resulting in tons of oil poured into seas, oceans, and soils. [ 26,27 ] In the article by Chen et al, [ 28 ] several examples of crude oil spill accidents were covered. On the word of the Brazilian Institute for the Environment and Renewable Natural Resources (IBAMA), Brazil experienced the most significant environmental disaster in 2019 caused by crude oil spillage.…”

Section: Introductionmentioning

confidence: 99%

Envelopes with microplastics generated from recycled plastic bags for crude oil sorption

Martins

Zanini

Botelho

et al. 2021

Oil spill accidents in marine environments and the lack of disposal of post‐consumer plastic are environmental problems worldwide. This study presents a sustainable alternative for both issues through envelopes filled with microplastics (MPs) from recycled bags for the sorption of spilled crude oil. Through particle size analysis by three different sieves (4, 9, and 20 mesh), different MP sizes were characterized by scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), density, contact angle (CA), and Fourier‐transform infrared spectroscopy (FTIR). According to their sizes, the MPs were distributed in envelopes and submitted to crude oil sorption capacity and efficiency evaluation. Three MP particle sizes were obtained (from the largest to the smallest, according to the sieve mesh, MP4, MP9, and MP20). SEM images of samples exhibited irregular and porous surfaces, and MP4 had the smallest pore size (8.6 μm). BET showed that MP4 had the highest surface area (0.074 m2/g). The CA > 90° exposed that all samples were hydrophobic. FTIR spectrum demonstrated that the samples from the recycled bags were made of high density polyethylene (HDPE). The MP4 envelopes also had the best crude oil sorption results in capacity and efficiency (1.73 g/g and 68%, respectively), being a promising recycled sorbent in crude oil spillage applications.

“…The compressive modulus of the three PE-xerogel (315-543 kPa) is higher than the neat PE foam (239 kPa). The compressive modulus for the neat PE foam was very close (237 kPa) in Reference [30]. It is clear that the introduction of the brittle silicate xerogel inside the PE foam solves the handling problem.…”

Section: Thermal Conductivity and Mechanical Propertiesmentioning

confidence: 65%

High‐performance thermal insulator based on polymer foam and silica xerogel

Chen

Nagamine

Ohshima

et al. 2021

Self Cite

In this work, methyltrimethoxysilane (MTMS) was used as a precursor, n-hexadecyltrimethylammonium bromide (CTAB) as a surfactant, and EtOH/ H 2 O as a co-solvent, while 10 mM HCl and urea were used as acid and base catalysts to prepare silica xerogels and xerogel inside the cells of a polyethylene (PE) foam via a sol-gel process combined with ambient pressure drying. The xerogels and PE-silica xerogel foams were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller method (BET), and thermal conductivity. The results indicate that the xerogels have a three-dimensional nanoporous structure, and the specific surface areas of the SiO 2 xerogel and PE-xerogel foam are 536 and 377 m 2 /g, respectively. The PE-xerogel foam exhibited very low thermal conductivity (22-24 mW/m.K) compared with conventional insulation materials on the market (30-50 mW/m.K). The thermal insulation properties of PE-silica xerogels were increased by 45% and 49% compared with neat PE foam. Additionally, the compressive modulus and density of the PE-xerogel foam was increased by the presence of the silica xerogel.These PE-xerogel foams are believed to be excellent candidates for thermal insulation applications in terms of cost/performance.