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Biowaste-Derived Components for Zn–Air Battery
Published in Ram K. Gupta, Tuan Anh Nguyen, Energy from Waste, 2022
Yiyang Liu, Tasnim Munshi, Jennifer Hack, Ian Scowen, Paul R. Shearing, Guanjie He, Dan J. L. Brett
As a key component in electrodes, the main responsibility of the polymer binder is to maintain the stability and integrity of the structure and build an effective conductive skeleton. Currently, fluorinated vinyl polymers (e.g., polyvinylidene fluoride (PVDF)) and organic solvents (e.g., N‐methylpyrrolidone (NMP)) are widely used as binders and dispersants for the electrode fabrication. However, they still have limitations. First, the non-polar structure of PVDF can only form weak intermolecular interactions with active materials and current collectors. Therefore, during cycling, the homogeneous composite structure of the pristine electrode will be destroyed, resulting in mechanical failure and capacity degradation. Second, PVDF is an electrically insulating material, so it requires carbon additives to improve the electronic conductivity of the electrode. However, because the PVDF/C mixture does not possess catalytic activity, it will reduce the overall electrochemical performance of ZABs. Finally, the volatile and toxic NMP solvent will result in health and environmental problems due to the poisonous nature of the organic solvent and the elevated safety risks from their flammability at elevated temperatures [17].
Methane Conversions
Published in Saeed Sahebdelfar, Maryam Takht Ravanchi, Ashok Kumar Nadda, 1 Chemistry, 2022
Saeed Sahebdelfar, Maryam Takht Ravanchi, Ashok Kumar Nadda
Acetylene is commercially produced from a variety of sources such as coal (calcium carbide, CaC2 process) and hydrocarbons (thermal or cracking processes). It is also a by-product of steam crackers. There are several uncatalyzed thermal processes for converting hydrocarbons ranging from methane to light naphtha to crude oil into acetylene. The trend in process development has been towards using heavier oil fractions, residual oils and even coal (Schobert, 2014). The common feature of the processes is rapid heat transfer rate to high (>1,400°C) temperatures, very short contact times (1–10 ms), low acetylene partial pressures and rapid quenching of pyrolysis gases. Acetylene is extracted from the cracked gas containing 5–20 vol.% C2H2 using selective solvents such as dimethylformamide (DMF), N-methylpyrrolidone (NMP), kerosene, methanol or acetone and is finally purified (Weissermel and Arpe, 1997).
The Polymeric Matrix and its Influence
Published in Maik W. Jornitz, Theodore H. Meltzer, Sterile Filtration, 2020
Maik W. Jornitz, Theodore H. Meltzer
The casting formula compositions and their methods of utilization, which have an effect on the resulting filter residuals, are proprietary. Early formulations described in the literature (Elford, 1931) used high boiling etheryl and ester derivatives of ethylene glycol as pore formers. There is reason to believe that such agents, as well as ethylene glycol itself, may still be used. In some cases, formic acid may be used as a solvent. In others, acetone, dioxane, dimethylformamide, N-methylpyrrolidone, methylene chloride, dioxane, and the like may be employed. Glycerine may be used as a pore former; it serves also to plasticize the cellulose triacetates in conjunction with heat to permit the pleating of these otherwise brittle materials. Glycerine is often allowed to remain in the filter for its humectant properties, to reduce membrane brittleness, and to aid in rapid wetting of the membrane. The consequent membrane hygroscopicity could, under certain conditions, lead to the promotion of mold growth. Sometimes, therefore, propionate salts are added to prevent such organism proliferations.
Synthesized Fe-doped Co3O4 nanoparticles-based anode for high-performance lithium-ion batteries application
Published in International Journal of Green Energy, 2023
Lanlan Feng, Guofa Mi, Zhenluo Yuan, Zeping Liu, Baozhong Liu, Guangxin Fan
Electrochemical properties of pure Co3O4 and Fe-doped Co3O4 products were examined by CR2016 coin cells, with lithium slice as the cathode electrode. The working electrode consisted of the active materials, conductor (acetylene black, ATB) and binder (polyvinylidene fluoride, PVDF) with a mass ratio of 7:2:1, and N-methylpyrrolidone (NMP) as a solvent that was spread uniformly on copper foil and dried at 100°C for 10 h under vacuum. The mass loading of active material on each electrode was about 1.2–1.4 mg. The coin cells were assembled in an argon-filled glove box with the polypropylene film (Celgard 2300) as a separator and 1 M LiPF6 in the volume ratio of 1:1 mixture of ethylene carbonate/dimethy1 carbonate (EC/DMC) as the electrolyte. Discharge/charge tests with constant current were conducted by a Neware Battery Test System in the voltage ranges of 0.01 ~ 3.0 V at room temperature. Cyclic voltammetry (CV) measurements were achieved by an electrochemical workstation (Chenhua CHI600E) in a voltage range of 0.01 ~ 3.0 V at a scan rate of 0.2 mV/s. Electrochemical impedance spectrum (EIS) tests were carried out on an electrochemical workstation system (PARSTAT 2273) over the frequency range of 100 kHz to 50 mHz and a sine wave amplitude of 5 mV.
Restricted substances for textiles
Published in Textile Progress, 2022
Arun Kumar Patra, Siva Rama Kumar Pariti
In textile manufacturing, the chemical formulations likely to contain VOCs could be adhesives, polyurethane coatings, some finishing formulations, degreasing agents and spot cleaners. So, safer alternatives need to be used in such cases. For example, water-based adhesives typically have far fewer hazardous chemical ingredients compared to solvent-based ones and are now preferred except for the cost of attaining higher drying temperatures. Only those solvent-based adhesives with chemical compliance may be used. Instead of adhesives with restricted VOCs, methylcyclohexane-based adhesives should be used. In the case of PU (polyurethane), synthetic PU-leather and PU coatings commonly-used solvents are N,N-dimethylformamide (DMF), toluene, N-Methylpyrrolidone (NMP), methyl ethyl ketone and N,N dimethylacetamide (DMAC). Most companies following AFIRM regulations restrict the use of these substances as they are a regular cause of RSL failure due to inadequate drying/curing conditions. The manufacturing units in such cases may end up releasing the solvents into the ambient air while the residual amounts on the textile materials harm the end user. Hence water-based PU, which is now an established technology is preferred in footwear, apparel and accessories. Similarly, N-heptane can be used as an alternative for benzene in paints, thinners, synthetic resins, rubber adhesives and textile finishes (https://afirm-group.com/afirm-rsl/).
Degradation of Tetramethylammonium Hydroxide through the Coupling of Ozonation with Other Advanced Oxidation Processes
Published in Ozone: Science & Engineering, 2020
Wastewater from high-tech industries may contain a variety of organic solvents or compounds, such as dimethyl sulfoxide, n-methylpyrrolidone, isopropyl alcohol, ethanolamine, and tetramethylammonium hydroxide (TMAH), which are toxic for microorganisms and the environmental ecology. The TMAH is a toxic and corrosive organic compound, which is mainly used for lithography processes in the integrated circuit and semiconductor industries in Taiwan. The properties of real wastewater obtained from a thin-film transistor liquid-crystal display factory in Northern Taiwan (Table 1) indicated a possible TMAH concentration ranging from 400 to 430 mg L−1 (You et al. 2015). Several accidents involving the skin exposure to TMAH have occurred in Taiwan, leading to three deaths caused by acute poisoning (Wu et al. 2008, 2012). In addition, the control criteria of TMAH in effluents or discharges postulated by the Hsinchu Science Park, Taiwan, have been reduced from 60 mg L−1 before 2013 to 30 mg L−1 in 2014. The excess discharge of TMAH into the water damages aquatic ecosystems and results in excess nitrogen compounds, which enter the water and may cause a large amount of algal bloom and the eutrophication of rivers, streams, lakes, and reservoirs (Mori et al. 2015).