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Electroactive Polymers and Their Carbon Nanocomposites for Energy Harvesting
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Tariq Altalhi, Nanogenerators, 2023
B.T.S. Ramanujam, Reshma Haridass, Pranesh Muralidharan, Ashok Kumar Nanjundan, Deepak Dubal, Pratheep K. Annamalai
Wu et al. [55] have reported drastic enhancement in power generation when 0.15 wt% graphene was incorporated into P(VDF-TrFE) matrix. The composites were synthesized as a combination of solution casting, stretching, heat treatment, and electric poling. The poling was done in the electric field range of 10 MV/m–60 MV/m with the increment of 10 MV/m at each step. DMF was used as a solvent. The stretching of the composites had a major influence on crystallization of β phase of the composite films. Scanning electron microscopy (SEM) images clearly revealed the alignment of P(VDF-TrFE) molecular chains in the direction of stretching. The stretching of polymer films enhanced the piezoelectric performance of the composite. Maximum open-circuit voltage of 12.43 V was obtained at an optimal loading of 0.15 wt% graphene, which was twice that of the value obtained for pure P(VDF-TrFE) (6.10 V). A maximum power of 148.06 W/m3 was harvested at 0.15 wt% graphene in the polymer at a load resistance of 16.92 MΩ. Under identical conditions, the power value obtained for P(VDF-TrFE) film was 36.77 W/m3.
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Published in Luis Liz-Marzán, Colloidal Synthesis of Plasmonic Nanometals, 2020
Isabel Pastoriza-Santos, Luis M. Liz-Marzán
N,N-dimethylformamide (DMF) is well-known for its high synthetic value, to a large extent due to its wide liquid temperature range, good chemical and thermal stability (even at its boiling point, 153 °C), high polarity and wide solubility range for both organic and inorganic compounds.[4] This uniquely versatile and powerful chemical has been used as a solvent in a wide variety of synthetic procedures, including: preparation of colloids,[5–7] synthesis of block-copolymers,[8,9] and many types of organic chemistry reactions.[10] The important role played by DMF as a solvent and reaction medium has motivated studies related to its redox activity. For example, the kinetics and mechanism of DMF oxidation have been studied by a number of groups, using oxidants such as osmium(VIII)[11] or nickel (IV)[12] in basic medium, and chromium(VI)[13] and manganese(III),[14] in acidic medium.
SOLVENT SELECTION CRITERIA
Published in Nicholas P. Cheremisinoff, Industrial Solvents Handbook, Revised And Expanded, 2003
Ketones are solvents for dyes, resins and waxes. They are also used in the manufacture of plastics, synthetic fibers, explosives, cosmetics and medicines. Examples of ketones are acetone, methyl ethyl ketone (MEK) cyclohexanone and isophorone. Some ketones such as acetone and MEK are extremely flammable. Several ketones are absorbed through the skin. Symptoms associated with overexposure include those common to many other organic solvents. Methyl butyl ketone may cause muscle weakness and numbness in the hands and feet. Some damage the liver and kidneys. Other solvents include Freon, turpentine, dimethylformamide (DMF), and carbon disulfide. Exposure to high concentrations of Freon may cause irregular heartbeats. It also forms phosgene gas when heated. Turpentine causes irritation, headaches, dizziness and balance problems. It can be a sensitizer. Mineral spirits are often used as a substitute. DMF can cause headaches, dizziness, nausea, liver damage, and dermatitis. It is a suspect carcinogen for testicular cancer. Carbon disulfide is absorbed through the skin. Overexposure causes headaches, dizziness, poor sleep, nervousness and psychosis. It can also damage the liver, kidney and nervous systems. It is extremely flammable. Some useful references are the following:
Environmentally friendly waterproof and breathable membranes via electrospinning
Published in The Journal of The Textile Institute, 2023
Wen Zhou, Jianyong Yu, Shichao Zhang
The philosophy of selection guides for green solvents is usually based on the impacts of solvents on the safety, health, and environment. By evaluating the Environment, Health, and Safety (EHS) scores, greener solvents can be determined in the event of higher scores according to the GSK guide (Alder et al., 2016). The commonly used 51 solvents can be ranked into three grades: recommended, problematic, and hazardous (Avossa et al., 2022; Prat et al., 2014). Unfortunately, DMF and THF are considered to be hazardous, carcinogenic, and mutagenic, although they have been widely used in the production of PIM nanofiber WBMs. To address this problem, Lasseuguette et al. developed amidoxime-modified PIM-1 (AO-PIM-1) nanofibers using dimethyl sulfoxide (DMSO) as a spinning solvent, as shown in Figure 6a and b (Lasseuguette, Malpass-Evans, Casalini, et al., 2021). It was found that bead-free and uniform electrospun AO-PIM-1 fibers could be prepared using the green DMSO solvent. Furthermore, as a greener solvent, ethanol can be prepared from grasses and agricultural residues, thereby drawing substantial research interest in environmentally friendly electrospun WBMs.
Layer by layer nanocomposite filter for ABC filtration
Published in Chemical Engineering Communications, 2021
Arun Karthick Selvam, Devi Baskar, Gobi Nallathambi
PAN (MW 150,000 g/mol) and 2-CEES of 98% purity were obtained from Sigma–Aldrich, St. Louis, USA. Dimethylformamide (DMF), a solvent, from Merck India Ltd. was used to prepare PAN solution. Silver nitrate, a precursor for Ag NP synthesis was purchased from SRL chemicals India Ltd. Magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, butyl titanate, cetyl trimethyl ammonium bromide (C-TAB) and liquid ammonia from Merck India Ltd. were used to prepare MA NP. Chloroform and decane from SRL Chemicals India Ltd. were used in the detoxification study of 2-CEES. For antibacterial study, nutrient broth was obtained from Himedia, India and the bacterial strains E. coli (MTCC 1303) and S. aureus (MTCC 96) were procured from Microbial Type Culture Collection, India. All chemicals were of analytical reagent grade.
Efficient synthesis of vitamin A palmitate in nonaqueous medium using self-assembled lipase TLL@apatite hybrid nanoflowers by mimetic biomineralization
Published in Green Chemistry Letters and Reviews, 2018
Liqing Xu, Jianyun Yu, Anming Wang, Chengyi Zuo, Huimin Li, Xinxin Chen, Xiaolin Pei, Pengfei Zhang
The effect of medium on the yield of vitamin A palmitate is shown in Figure 4. According to the yield in the different media, petroleum ether was found to be suitable for the enzymatic synthesis of the target product. When the ratio of PE (V/V) to water was 8:2, the yield catalyzed using TLL@apatite hNFs was up to 90.39%, about 1.5 folds of that using free TLL (61.31%). Moreover, the yield in this medium was not only higher than that in N, N-Dimethylformamide (DMF) but also less toxic. In the synthesis of vitamin A palmitate, vitamin A acetate and palmitic acid are hydrophobic with low polarity. When DMF was used as a medium, it can present good solubility and the yield of product can also reach a certain level for hNFs catalysis. However, DMF is highly harmful to environment and toxic to human body and should be used with caution. Among the remaining solvents, n-hexane was also a slightly suitable medium for higher catalytic property for hNFs, and this solvent with less polarity may also be a good reaction medium.