Polymers
·
2023
·Vol. 15
·期 13
·2812
·
IF 5
Yingwei Zhang,Chunhua Wang,Yong Yi,Wenzhi Wang,Jun Yang
In order to adjust the properties of polyamide 6 (PA6) and expand its application, a new strategy of introducing an aromatic imide structure into the PA6 chain through the random copolymerization method is reported. The diimide diacid monomer was first synthesized by the dehydration and cyclization of pyromellitic dianhydride and 6-aminocaproic acid before it reacted with 1,6-hexamethylene diamine to form poly(amide imide) (PAI) salt, and finally synthesized PA6/PAI random copolymers containing an aromatic imide structure by the random copolymerization of ε-caprolactam and PAI salt. The introduction of an aromatic imide structural unit into the PA6 chain could have a great influence on its properties. As the content of PAI increases, the crystallinity (Xc) and melting temperature (Tm) of the PA6/PAI random copolymer gradually decrease, but its glass transition temperature (Tg) increases obviously. When the PAI content is 20 wt%, the copolymer PA6/PAI-20 has the best comprehensive performance and not only has high thermal stabilities but also excellent mechanical properties (high strength, high modulus, and good toughness) and dielectric properties (low dielectric constant and dielectric loss). Moreover, these properties are significantly superior to those of PA6. Such high-performance PA6 random copolymers can provide great promise for the wider applications of PA6 materials.Keywords:polyamide 6;poly(amide imide);random copolymerization
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Physiology
·
2020
·
IF 3.367
Li Fan,Li Ke,Wu Li-Juan,Fan Yong-Liang,Liu Tong-Xian
Oviposition is an important reproductive behavior that is triggered by mating in insects, and biogenic amines might be involved in its regulation. The effects of biogenic amines on oviposition have only been studied in a few insect species, and the findings to date have not been conclusive. In addition, there are few studies on the effects of biogenic amines on oviposition of the diamondback moth, Plutella xylostella L. Here, we tested how mating and biogenic amines regulate oviposition of P. xylostella by injecting amines and amine receptor antagonists into virgin and mated females and counting the number of eggs laid afterward. Biogenic amines of octopamine and tyramine could induce virgin adults of P. xylostella to lay eggs, while dopamine and serotonin had no such effect on oviposition. Furthermore, the octopamine antagonists mianserin, epinastine, and phentolamine inhibited oviposition by mated females. The tyramine antagonist yohimbine, dopamine antagonist SCH23390, and serotonin antagonist ketanserin did not block oviposition by mated females, and octopamine and tyramine-inducing oviposition by virgin females could be inhibited by the octopamine antagonists mianserin and epinastine instead of the tyramine antagonist yohimbine. We conclude that octopamine and its receptors are involved in mating-triggered oviposition in P. xylostella, while tyramine acts as a subsidiary. Further, the inducing effect of tyramine on oviposition is achieved via octopamine receptors instead of tyramine receptors. This experiment is helpful to further understand the role of biogenic amines in mating regulation and to provide a new strategy for controlling P. xylostella.
研究领域:
昆虫学
·
神经生物学
✓ 已验证
DOI
PubMed
高影响因子
MOLECULES
·
2019
·Vol. 24
·期 20
·3718
·
IF 3.06
Mao-Long Chen,Shu-Yang Zhou,Zhou Xu,Li Ding,Yun-Hui Cheng
MIL-100(Fe, Cr) and MIL-101(Cr) were synthesized by the hydrothermal method and applied to the adsorptions of five aromatic amines from aqueous solutions. These three metal-organic frameworks (MOFs) were well characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and surface area analysis. The adsorption mechanism of three MOFs and the effects of the structures of MOFs on the adsorption of aromatic amines were discussed. The results show that the cavity system and suitable hydrogen bond acceptor were important factors for the adsorption for five aromatic amines of aniline, 1-naphthalamine, o-toluidine, 2-amino-4-nitrotoluene and 2-nitroaniline: (a) the saturated adsorption capacity of aniline, 1-naphthylamine and o-toluidine on MIL-100(Fe) were 52.0, 53.4 and 49.6 mg/g, respectively, which can be attributed to the intermolecular hydrogen bond interaction and cavity system diffusion. (b) The adsorption capacity of 2-nitroaniline and 2-amino-4-nitrotoluene on MIL-101(Cr) were 54.3 and 25.0 mg/g, respectively, which can be attributed to the more suitable pore size of MIL-101(Cr) than that of MIL-100(Fe, Cr). The MOFs of MIL-100(Fe) and MIL-101(Cr) can be potential materials for removing aromatic amines from aqueous solutions.Keywords:metal-organic framework;adsorption;aromatic amines;aniline;1-naphthalamine;o-toluidine;2-amino-4-nitrotoluene;2-nitroaniline
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2018
·
IF 1.551
Yanbin Wang,Teng Wang,Tingmu Wang,Jinyi Zhang,Jinxing Chen,Rui Yang,Linxiao Ruan,Biaobing Wang
Recently, multifunctional films are of particular interest to scientists owing to their diversified properties. Here, we demonstrated that self-cleaning, self-extinguishing, and high conductive films were fabricated by simple solvent-casting method from poly(amide-imide)/polyaniline composites. The multifunctional films exhibited controllable water contact angles varying from 65° to 120° and high electrical conductivities of over 40 S m −1 . Moreover, due to the improved hydrophobicity, the multifunctional films showed self-cleaning characteristics and were used to collect the dust powders easily and perfectly during the dispensed water droplet rolling off the solid surface. Furthermore, the self-extinguishing property of the multifunctional films was confirmed by thermogravimetric analysis. The special film composition and morphology are the two important aspects that induce such unusual properties. The polyaniline content can strongly influence the morphology of the composite films, which in turn display different hydrophobicities and conductivities. POLYM. ENG. SCI., 59:E33–E43, 2019. © 2018 Society of Plastics Engineers
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Chengyu Yang,Weixing Xu,Yang Nan,Yiguang Wang
Solvent-resistant nanofiltration (NF) membranes have numerous application prospects. In this study, a novel solvent-resistant nanofiltration membrane with a double layered polyamide structure was prepared for efficient desalination. The substrate was polyimide crosslinked with m -phenylenediamine (MPD), and the surface layer was polyamide prepared by typical interfacial polymerization. The crosslinking was confirmed by Fourier transform infrared spectroscopy . Investigation of the effects of different reaction conditions on membrane performance showed that the optimal reaction conditions were found to be: 5% aqueous MPD solution with crosslinking time of 10 min and piperazine concentration of 0.1% (m/v). The rejection rate for sodium sulfate and sodium chloride were 99.13% and 97.45%, respectively. The membrane morphologies were studied by scanning electron microscopy and atomic force microscopy . The membrane showed electronegativity in the pH range of 3.0–10.0 and its contact angle was 54.28°, indicating excellent hydrophilicity. After soaking in several solvents for a week, the membrane still had a high rejection rate of more than 90% for Na 2 SO 4 , demonstrating its excellent solvent resistance .
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Siying Tan,Shaojie Jiang,Yangzhou Lai,Qiuhong Yuan
Cationic polymers, which are commonly used as flocculants and coagulant aids in water and wastewater treatment , have been recently reported to promote the formation of nitrosamines . Most of the findings to date are based on poly (epichlorohydrin dimethylamine) and poly (diallyldimethylammonium chloride), while few studies have considered nitrosamines formation of polyacrylamides. In this work, the nitrosamines formation from non-ionic, anionic and cationic polyacrylamides was evaluated. Moreover, the effects of chemical structures of cationic polyacrylamides (including molecular weight , charge density, and monomers) on nitrosamines formation were investigated. The results revealed that the highest amount of nitrosamines formation was formed from cationic polyacrylamide, followed by non-ionic polyacrylamide and anionic polyacrylamide. Molecular weight and various cationic monomers showed no significant effects on nitrosamines formation, but monomers generated significantly higher amount of nitrosamines formation than cationic polyacrylamides. Nitrosamines formation increased with the increasing charge density of cationic polyacrylamides, and FTIR analysis results showed that the quaternary amine groups preferentially reacted with chloramines than with amide groups. This work shed new light on the nitrosamines formation from water and wastewater treatment polymers.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2014
·
IF 3.377
Tianfu Li,Naimin Shao,Yuntao Liu,Jingjing Hu,Yu Wang,Li Zhang,Hongli Wang,Dongfeng Chen,Yiyun Cheng
We investigate the interactions of generation 3 (G3) poly(amidoamine) (PAMAM) and G3 poly(propylenimine) (PPI) dendrimers with sodium dodecyl sulfate (SDS) in aqueous solution. Size and structure of the dendrimer–SDS aggregates as a function of SDS/dendrimer molar ratio were revealed by SAXS and NMR. G3 PAMAM has a relatively open and dense-core structure, while G3 PPI with the same number of surface amine groups possesses a compact and uniform structure. Upon addition of SDS, much more SDS monomers were encapsulated in the interior of PPI rather than in PAMAM. More significant size increase in PAMAM–SDS aggregate is observed at low SDS concentrations, due to the binding of SDS on PAMAM surface and further assembly into larger supramolecular structures. Both noncooperative and cooperative binding of SDS on G3 PPI surface are observed, while only noncooperative binding is proposed on G3 PAMAM, due to its open surface and large surface group distance. The size of the PPI–SDS complex is larger than that of PAMAM–SDS at higher SDS concentrations. Within the investigated SDS concentrations, SDS exhibits much stronger interactions with G3 PPI than with G3 PAMAM. These results provide new insights into dendrimer–surfactant interactions and explain why PPI is much more cytotoxic than PAMAM.
研究领域:
生物化学
·
材料科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2020
·
IF 2.87
Yan Ji,Xiaoliang Yang,Zhi Ji,Linhui Zhu,Nana Ma,Dejun Chen,Xianbin Jia,Junming Tang,Yilin Cao
The infrared spectrum (IR) characteristic peaks of amide I, amide II, and amide III bands are marked as amide or peptide characteristic peaks. Through the nuclear magnetic resonance study, N-methylacetamide has been determined to have six fine components, which include protonation, hydration, and hydroxy structures. Then the independent IR spectrum of every component in N-methylacetamide is calculated by using the density functional theory quantum chemistry method, and the contribution of each component to amide I, II, and III bands is analyzed. The results of this research can help to explain the formation of the amide infrared spectrum, which has positive significance in organic chemistry, analytical chemistry, and chemical biology.
研究领域:
有机化学
·
分析化学
·
化学生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Yi-Hsueh Chuang,Chia-Shun Chou,Yi-Lin Chu
Chlorination of ammonia or chloramine-containing waters induces breakpoint chlorination reactions, producing a hydroxyl radical (•OH), but enhances the formation of undesirable N-nitrosamines. The prevailing view attributes •OH formation to a nitrosyl intermediate derived from the hydrolysis of dichloramine, but this pathway is unlikely at neutral or acidic pH. This study reveals a novel mechanism where •OH is generated via interactions between trichloramine (NCl3) and dichloramine (NHCl2), which also form nitrosation agents. Our experiments demonstrated that the NCl3–NHCl2 interaction degrades micropollutants with kinetics 2–3 times faster than breakpoint chlorination. Using electron paramagnetic resonance, we detected •OH in the NCl3–NHCl2 reaction. Micropollutant removal was unimpaired under low dissolved oxygen (O2(aq)) conditions, aligning with negligible O2(aq) changes during the NCl3–NHCl2 reaction and suggesting O2(aq) does not participate in •OH formation. Using benzene as a probe in 18O-labeled H2O, we confirmed water contributes to the oxygen source of •OH in NCl3–NHCl2 interactions, through which parallel reactions occur, leading to the formation of one mole of •OH alongside 1.92 mol of N2. A kinetic model developed in this study accurately predicted •OH and N2 and demonstrated the NCl3–NHCl2 interaction as the primary pathway for •OH formation in breakpoint chlorination, providing new insights into breakpoint chemistry.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Food Measurement and Characterization
·
2021
·Vol. 15
·期 2
·1747-1753
·
IF 2.431
Li Yi-Fang,Lin Zheng-Zhong,Hong Cheng-Yi,Huang Zhi-Yong
A facile colorimetric method for rapid detection of putrescine (Put) and cadaverine (Cad) based on the peroxidase-like activity of (Fe,Co) codoped-CDs was developed. With the enzymatic hydrolysis by diamine oxidase (EC 1.4.3.6, DAO), Biogenic amines (BAs) were decomposed to produce H 2 O 2 which oxidizes 3,3',5,5'-tetramethyl-benzidine with the catalysis of (Fe,Co)-codoped CDs. By means of principal component analysis, Put and Cad were differentiated from BAs and their total amounts were detected by measuring the spectral absorption at 652 nm with a linear range from 0.25 to 10 mg kg −1 . The colorimetric method was applied to the detection of Put and Cad in various fish samples with a detection limit ((3σ/k, n = 9)) of 0.06 mg kg −1 . Besides verifying with HPLC, the recoveries of the colorimetric method were also tested by spiking standards at three levels with the range of 98.2%–115.7%, indicating that the established colorimetric method was accurate and sensitive.
研究领域:
食品科学
·
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
SYNTHETIC METALS
·
2021
·
IF 3.266
Yanyu Gao,Wei Zhang,Dongxu Li,Xiaoxue Lin,Xin Qiao,Haijun Niu,Wen Wang
Electrochromic (EC) materials have captured intense attentions in the field of smart window, label screen and camouflage recently. The structure of EC active group is crucial to the properties of product. In this study, novel PAs with EC and memory properties were developed by polycondensation of asymmetry triarylamine N, N ' -bis(4-aminophenyl)-N-isopropyl-N ' -phenylbenzene-1,4-diamine (IPATAA) with five different dicarboxylic monomers. An isopropyl group of the IPATAA molecule is linked to a nitrogen atom to increase electron density and solubility. Furthermore, PAs are apt to be processed into a film by spin-coating or printing. After electro-oxidation, PAs films change from colorless to blue. The coloring time and bleaching time is 2.8–4.1 s and 2.6–4.5 s, respectively. The highest coloring efficiency of PAs film is 366 cm 2 C −1 . Memory devices made using the PAs show non-volatile memory characteristics such as lower switching threshold voltages (<1.08 V) and better switching current ratios (>2 × 10 4 ).
研究领域:
材料科学
·
电子器件
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2014
·Vol. 12
·期 33
·6399-6405
·
IF 3.487
Xinhua Cao,Tingting Zhang,Aiping Gao,Keli Li,Qiuli Cheng,Lijuan Song,Min Zhang
A new gelator 1 based on a simple naphthalimide derivative was synthesized and fully characterized. It was found that the organogel 1 was formed only in a mixed solvent of methanol and H2O (1/1, v/v). The organogel was thoroughly characterized by using various microscopic techniques including field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and UV-vis, fluorescence and Fourier transform infrared (FTIR) spectroscopy. Hydrogen bonds were the main driving force for the organogel formation. Interestingly, the organogel 1 exhibited the ability to distinguish aliphatic amines from aromatic amines. The gel state and fluorescence emission intensity were both changed after two minutes after the addition of aliphatic amines. This organogel system could be applied in the detection of aliphatic amine pollutants.
研究领域:
材料化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）