Elemental sulfur has been known since Antiquity and found widespread applications in the preparation of black gunpowder, the synthesis of sulfuric acid as well as other sulfur‐containing compounds, ...and the vulcanization of rubber. Over the last several years, we have come to better understand its properties and discover more applications of elemental sulfur in synthetic organic chemistry. This review summarizes the advances from 2000 in the construction of organic molecules using elemental sulfur via sulfuration, oxidation, reduction and redox condensation processes.
It is well known that heterocycles are among the most significant molecules for everyday life, ranging from natural products and bioactive substances to functional materials. This review will focus ...on the synthesis of heterocycles by reactions involving elemental sulfur published from 2017 until now.
Display omitted
•Well-textured nanopillars with various parameters were fabricated for the anti-icing behavior.•Nanopillars of very low top diameter irrelevant to height lead to reducing adhesion ...force and delaying freezing time.•Low top diameter of nanopillars also ensures the metastable Cassie-Baxter state based on energy barrier calculation.•Results demonstrated the important role of areal fraction and negligible contribution of height in anti-icing efficiency.
In this paper, we report the contributions of actual ice–substrate contact area and nanopillar height to passive anti-icing performance in terms of adhesion force and freezing time. Well-textured nanopillars with various parameters were fabricated via colloidal lithography and a dry etching process. The nanostructured quartz surface was coated with low-energy material to confer water-repellent properties. These superhydrophobic surfaces were investigated to determine the parameters essential for reducing adhesion strength and delaying freezing time. A well-textured surface with nanopillars of very small top diameter, regardless of height, could reduce adhesion force and delay freezing time in a subsequent de-icing process. Small top diameters of nanopillars also ensured the metastable Cassie–Baxter state based on energy barrier calculations. The results demonstrated the important role of areal fraction in anti-icing efficiency, and the negligible contribution of texture height. This insight into icing phenomena should lead to design of improved ice-phobic surfaces in the future.
Slippery liquid-infused porous surfaces (SLIPSs) have been actively studied to improve the limitations of superhydrophobic (SHP) surfaces, especially the defects of the nonwetting chemical coating ...layer and the weak mechanical robustness of surface micro/nanostructures. However, the SLIPSs also have several drawbacks including volatilization and leakage of lubricant caused by long-term usage. In this study, we suggest the use of icephobic, highly transparent, and self-healing solid slippery surface to overcome the limitations of both surfaces (SLIPS and SHP) by combining specific biomimetic morphology and intrinsic properties of paraffin wax. A moth-eye mimicking nanopillar structure was prepared instead of a porous structure and was coated with solid paraffin wax for water repellence. Moth-eye structures enable high surface transparency based on antireflective effect, and the paraffin layer can recover from damage due to sunlight exposure. Furthermore, the paraffin coating on the nanopillars provides an air trap, resulting in a low heat transfer rate, increasing freezing time and reducing adhesion strength between the ice droplet and the surface. The heat transfer model was also calculated to elucidate the effects of the nanopillar height and paraffin layer thickness. The antireflection and freezing time of the surfaces are enhanced with increase in nanopillar height. The paraffin layer slightly deteriorates the transmittance but enhances the icephobicity. The solar cell efficiency using a biomimetic solid slippery surface is higher than that of bare glass due to the antireflective effect. This integrated biomimetic solid slippery surface is multifunctional due to its self-cleaning, anti-icing, antireflection, and self-healing properties and may replace SLIPS and SHP surfaces.
In this study, biochar derived from spent coffee grounds (SCGB) was used to adsorb norfloxacin (NOR) in water. The biochar properties were interpreted by analysis of the specific surface area, ...morphology, structure, thermal stability, and functional groups. The impacts of pH, NOR, and ion's present on SCGB performance were examined. The NOR adsorption mode of SCGB is best suited to the Langmuir model (R2 = 0.974) with maximum absorption capacity (69.8 mg g−1). By using a Response Surface Method (RSM), optimal adsorption was also found at pH of 6.26, NOR of 24.69 mg L−1, and SCGB of 1.32 g L−1. Compared with biochars derived from agriculture such as corn stalks, willow branches, potato stem, reed stalks, cauliflower roots, wheat straw, the NOR adsorption capacity of SCGB was 2–30 times higher, but less than 3–4 times for biochars made from Salix mongolica, luffa sponge and polydopamine microspheres. These findings reveal that spent coffee grounds biochar could effectively remove NOR from aqueous solutions. Approaching biochar derived from coffee grounds would be a promising eco-friendly solution because it utilizes solid waste, saves costs, and creates adsorbents to deal with emerging pollutants like antibiotics.
Display omitted
•Norfloxacin was removed using biochar derived from spent coffee grounds (SCGB).•pH significantly influenced the Norfloxacin (NOR) adsorption of the SCGB.•Based on Langmuir model, the maximum absorption capacity was 69.8 mg g−1 at pH 6.•The adsorption process was optimized by using the response surface methodology.•Optimal adsorption conditions were achieved at pH of 6.26 and SCGB of 1.32 g L−1.
Display omitted
•Copper (II) is nonbiodegradable pollutants and major source of environment pollution.•Biochar showed effective removal of Copper (II) from aqueous phase.•Biochar showed >99% removal ...efficiency with 223 mg g−1 Cu (II) adsorption capacity.•Langmuir adsorption isotherm showed better fit of Cu (II) adsorption.•Biochar could be an attractive bioresource alternative to costly adsorbents.
There has been growing research interest in exploiting biochar for cost-effective.
removal of different pollutants. Heavy metals, especially copper II (Cu II) is highly toxic and nonbiodegradable pollutants, and has been major source of environmental pollution. In this study adsorption of Cu (II) on seaweed (Ascophyllum nodosum)-derived biochar was systematically examined. The removal efficiency based on surface property of biochar and type of interactions associated with biochar produced at varying pyrolysis conditions were investigated. The highest removal efficiency of Cu (II) from aqueous media was >99% with 223 mg g−1 Cu (II) adsorption capacity observed by biochar derived at 700 °C and pH 5. Langmuir adsorption isotherm described the adsorption mechanisms of Cu (II) on biochar with cationic and anionic electrostatic attractions, surface precipitation, and pore depositions. Thus, this study shows that waste biomass (seaweed) could be a valuable bioresource for heavy metal remediation from various water bodies.
Herein, a sponge membrane bioreactor (Sponge-MBR) combined with ozonation process was performed to remove the antibiotics which frequently existed in the hospital wastewater. Whilst seven antibiotics ...i.e., norfloxacin, ciprofloxacin, ofloxacin, sulfamethoxazole, erythromycin, tetracycline and trimethoprim were widely used in medications, this integration was applied for the evaluation of treatment performance under different fluxes. As the results, whilst the antibiotics were eliminated about 45–93%, the tetracycline was completely removed (100%) using Sponge-MBR operated at the flux of 10 LMH. For enhancement of antibiotics removal, the ozonation process was introduced to treat the membrane permeate. Overall efficiencies were 97 ± 2% (trimethoprim), 92 ± 4% (norfloxacin), 90 ± 1% (erythromycin), 88 ± 4% (ofloxacin), 83 ± 7 (ciprofloxacin) and 66 ± 1% (sulfamethoxazole). These results demonstrated Sponge-MBR coupled with ozonation could be a prospective technology for the hospital wastewater treatment.
Display omitted
•Sponge membrane bioreactor-ozonation was introduced to antibiotics removal.•High removal efficiencies were achieved for antibiotics, except sulfamethoxazole.•Ozonation enhanced sulfamethoxazole removal efficiency up to 66%.•Organics and nitrogen were significantly eliminated by Sponge membrane bioreactor.
A convenient synthesis of thiazole-2-thiones was developed based on base-catalyzed three-component reactions between chalcones, isothiocyanates, and elemental sulfur.
Display omitted
•The SCG derived biochars pyrolyzed at 300 and 500 °C had the lowest PAHs levels.•The PAHs levels in all biochars and pyrolysis oil met the related regulations.•The SCG 500 showed the ...highest tetracycline adsorption capacity.•pH affected tetracycline adsorption.•Surface interactions were major adsorption reactions.
The main objective of this study was to evaluate the effect of different pyrolysis temperatures on the formation of polycyclicaromatichydrocarbons (PAHs) in biochar originated spent coffee ground (SCG) and the tetracycline (TC) adsorption behavior of biochar in water. The results showed that biochar synthesized at 500 °C (SCG 500) contained low PAHs (600 µg kg−1) and the highest TC adsorption efficiency. In addition, the characteristics, influencing factors on TC adsorption, and the related mechanisms of SCG 500 were comprehensively investigated. The results showed that the highest efficiency was observed at pH of 7 and the presence of ions in salinity solution reduced the adsorption capacity of SCG 500. The electrostatic interaction, hydrogen bonding, and π-EDA were the major adsorption mechanisms. Safety PAHs level, low-cost, widely material sources and high TC removal capacity suggested that SCG 500 was a promising environmentally friendly effective absorbent.
PDF
