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Membrane Materials for Vanadium Redox Flow Battery
Published in Sam Zhang, Materials for Energy, 2020
The non-fluorinated membranes, especially those based on the aromatic polymers, have attracted a lot of interest, because of their high chemical stability, low cost, and simple preparation. A few examples include the poly(ether ether ketone), polyimide, polybenzimidazole, poly(arylene ether), poly(ether sulfone), and poly(phthalazinone ether ketone). Such kinds of aromatic polymers cannot be directly used as IEMs in the absence of conductive groups with strong hydrophobicity. However, they can be modified by introducing the desirable functional groups. The sulfonation is a simple way to enhance the conductivity, hydrophilicity, solubility in solvents, and membrane-forming ability. The non-fluorinated aromatic ring membrane is a promising alternative to the Nafion membrane. Some common non-fluorinated membranes are discussed here for the VRFB application, such as the sulfonated poly(ether ether ketone) with negatively charged groups (–SO3–), the polybenzimidazole with positively charged N-containing group, the amphoteric sulfonated polyimide, and other polymers.
Advanced Materials for Polymeric Ultrafiltration Membranes Fabrication and Modification
Published in Stephen Gray, Toshinori Tsuru, Yoram Cohen, Woei-Jye Lau, Advanced Materials for Membrane Fabrication and Modification, 2018
Mimi Suliza Muhamad, Noor Aina Mohd Nazri, Woei-Jye Lau, Ahmad Fauzi Ismail
Modification of commercial polymers can be carried out by introducing functional groups such as sulfonic (–SO3H), hydroxyl (–OH), carboxyl (–COOH), amino (–NH2), or fluorobenzene to the existing organic structure of the polymers. Sulfonation is a chemical reaction that takes place when a sulfonic acid group (–SO3H) is introduced into the structure of a molecule or ion to replace a hydrogen atom. For example, the sulfonation of PES can be performed by adding SO3H groups to the (aromatic) backbone of PES using sulfonating agents such as chlorosulfonicacid (ClSO3H), sulfuric acid (H2SO4) and trimethyl silylchlorosulfate ((CH3)3SiSO3Cl). The successful sulfonation of PES (SPES) will make it more advantageous to be used for UF membrane fabrication (Zhao et al., 2013b).
Polyion Complex Membranes for Polymer Electrolyte Membrane and Direct Methanol Fuel Cell Applications
Published in Sundergopal Sridhar, Membrane Technology, 2018
F. Dileep Kumar, Harsha Nagar, Sundergopal Sridhar
PEEK is an aromatic thermostable polymer with a non-fluorinated backbone with phenyl groups that are separated by ether (–O–) and carbonyl (–CO–) linkages. PEEK can be functionalized by sulfonation, and the degree of sulfonation (DS) can be controlled by manipulating reaction time and temperature. Sulfonation can be performed using concentrated sulfuric acid or oleum. SPEEK exhibits high thermal stability, mechanical strength and adequate proton conductivity that makes it ideal for FC application. However, excess swelling and low stability at high DS associated in SPEEK can be overcome by blending with other polymers (Adolfo et al., 2012).
Cashew nutshell liquid and its derivatives in oil field applications: an update
Published in Green Chemistry Letters and Reviews, 2021
David Chukwuebuka Ike, Millicent Uzoamaka Ibezim-Ezeani, Onyewuchi Akaranta
CNSL displays great susceptibility to structural modification, to effect desirable change or specific properties of high value. This structural change can be achieved via chemical modification on the hydroxyl group, aromatic ring, carboxylic group, and on the side chain (Figure 6). Natural cashew nutshell oil contains anacardic acids as a major fraction and this is usually transformed to cardanol during extraction or refining processes that involve heating, also during distillation of the oil at high temperature, and deliberate heating of the oil at a very high temperature to decarboxylate the acid functional group (Figure 6(a)) (49). Direct nitration of CNSL gives the nitro-derivatives, which are useful precursors for azo dye synthesis (51). Nitration of cardanol was reported to be achieved by its reaction with sodium nitrate in the presence of sulfuric acid at low temperatures (Figure 6(b)) (51). The sulfonation of cardanol (the major fraction of CNSL from heat extraction) has been reported to yield an alkyl aryl sulfonic acid or their metal salts (Figure 6(c)) (7, 13).
Separation of low polarity petroleum sulfonate: Eluant selection, characterization, and theoretical calculation
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2019
Xintong Liu, Yanan Xue, Youyi Zhu, Jian Fan, Shixiang Liu, Hongda Li, Yanjun Zhao, Wenjun Li
As shown in Figure 2, the asymmetric telescopic vibration peaks of –CH3 and – CH2– are respectively located at 2,930 and 2,860 cm−1.20 The peak of 2,360 cm−1 may be identified as carbon dioxide peak (Grillo, Natile, and Glisenti 2004), which is not easy to be deducted due to the instrument using air as the background. The peak at 1,620 cm−1 is considered as the telescopic vibration peak of C=C double bond (Zhu et al. 2012). The asymmetrical deformation vibration and symmetric deformation vibration peak of –CH3 are respectively in the vicinity of 1,380 and 1,460 cm−1.23 The peaks at 1,190 and 1,050 cm−1 are caused by S=O symmetric stretching vibration and asymmetric stretching vibration of sulfonate (Deimede et al. 2000). As for the strong peak of 3,450 cm−1, it is caused by traces of water in the sample (Fang et al. 2009). This indicates that components A–D contain sulfonic acid and C=C structure. The content of C=C structure in C component is obviously the lowest. The content of sulfonic acid in A and B components is significantly higher than that of component C and D, which may attribute to the much lower sulfonation degree of component C and D than that of A and B.
Influence of sulfonic acid group on the performance of castor oil acid based methyl ester ethoxylate sulfonate
Published in Journal of Dispersion Science and Technology, 2018
Jingjie Zhou, Yongqiang Sun, Kehua Zhu, Martino Di Serio, Yong Zhang, Jinyuan Sun, Huaping Wu, Lirong Ding, Huibin Liang
The structure of CAMEES was confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). Figure 4 showed the FT-IR spectra of CAMEES and CAMEE. In the FT-IR spectra, the signal at 1110 cm−1 was assigned to the vibration of the ether group (-(CH2CH2O)nH), the signal at 1733 cm−1 was represented to the ester group (-COO-). Both CAMEE and CAMEES have the two same absorption bands, indicating that the sulfonation reaction had no effect on the polyether and ester ether. The new signals at 1039 cm−1was assigned to the absorption peak of sulfonic group. The difference between CAMEE and CAMEES at the 1039 cm−1 showed that the sodium bisulfite sulfonation method can successfully graft the sulfonic acid group to the double bond of carbon. Furthermore, the two-phase titration procedure (according to 2.2) proved that the anionic content of the purified CAMEES reached above 99.0%. From these results, we can conclude that new CAMEES can be successfully synthesized using the sodium bisulfate sulfonation method and upon extraction high purity can be achieved.