SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Menglan Gao,Zhibin Jiang,Xiaobin Liao,Huan Qi,Lei Zhao,Chao Chen,Danielle Westerman
Aliphatic amines, common constituents that contribute to dissolved organic nitrogen (DON), can quickly react with ozone due to the lone electron pair on the nitrogen atom and this may produce carcinogen N -Nitrosodimethylamine (NDMA). 3-(Dimethylamino)-1-propylamine (DMAPA) was chosen as a representative to elucidate the NDMA formation characteristics, kinetic rates, reaction pathways, and influencing factors during ozonation in this study. The results demonstrated that NDMA generated directly from DMAPA during ozonation. Moreover, the NDMA yields increased with ozone dosages. The NDMA molar yield increased and then decreased when the pH raised from 5 to 9, achieving the maximum value at pH 8. Hydroxyl radical (∙OH) played a promotional role in NDMA formation, and its scavenger dramatically cut down its yields. Low levels of Br − facilitated NDMA formation, while the value significantly reduced when Br − was up to 1 mM. The NDMA amount was slightly raised by NO 2 − , but it was inhibited by NH 4 + and NO 3 − . Moreover, it was also depressed by co-existing components in actual lake water. Based on the result of the Gaussian calculation, the LC-MS/MS and GC–MS analysis, four possible transformation pathways were proposed. The radical recombination was verified to be the primary pathway for ozone promoting NDMA formation from DMAPA.
研究领域:
环境科学
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化学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Liu Yang,Jiawei Chen,Ning Ma,Zhenchang Fang,Xinling Li,Zhen Huang
A novel diamine-based biphasic absorbent, 3-(Dimethylamine)-1-propylamine (DMAPA)-Sulfolane-Water, was proposed for equimolar CO 2 absorption with high absorption–desorption efficiency. To optimize the CO 2 capture performance of the proposed DMAPA-Sulfolane-Water biphasic absorbents, the phase separation experiments and the absorption–desorption cyclic experiments were conducted. The results indicated that the DMAPA-Sulfolane-Water biphasic absorbent could realize a liquid–liquid phase separation performance after CO 2 absorption with sulfolane as the phase splitter and generate a CO 2 -rich upper-phase and a CO 2 -lean lower-phase. An equimolar absorption (1.023 mol CO 2 /mol DMAPA), a high initial absorption rate (0.106 mol/(L*min)), a low viscosity (10.96 mPa . s) and a high CO 2 loading (3.68 mol/L) of the CO 2 -rich upper-phase, a high desorption efficiency (92 %), and high cyclic stability were obtained due to the interaction of the intramolecular primary and tertiary amino groups in DMAPA. The minimum volume percentage of the rich phase was as low as 32 % of the total volume. In addition, temperature was confirmed to be an essential factor in the absorption and desorption process. The species in the two phases after CO 2 absorption were identified by 13 C NMR, not only further identifying the CO 2 -rich upper-phase but also revealing the mechanism of equimolar absorption by the DMAPA-Sulfolane-Water biphasic absorbents because of the high carbon peak of carbamic acid (DMAPACOOH) in the upper-phase. The quasi-salting out effect and the improved polarity of the solvents were proved to trigger the phase separation.
研究领域:
化学工程
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环境科学
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材料科学
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2026
·Vol. 27
·期 5
·2486
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IF 5.6
Liming Shi,Yuheng Liao,Zeng Hong,Jiancheng Ruan,Shaodong Zhou,Chen Wu,Chao Qian
N,N-Dimethyl-1,3-propanediamine (DMAPA) is an important aliphatic diamine widely used in fine chemical manufacturing. Its industrial production traditionally relies on Raney nickel catalysts, which suffer from pyrophoric hazards and limited selectivity due to imine condensation side reactions. To address these challenges, we report an Al2O3-supported Ni-Cu alloy catalyst as an efficient alternative for the selective hydrogenation of N,N-dimethylaminopropionitrile (DMAPN). The optimized Ni30Cu5/Al2O3catalyst achieves complete DMAPN conversion and over 90% DMAPA selectivity under industrially relevant conditions (120 °C, 2.5 MPa H2). X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy analyses confirm the formation of substitutional Ni-Cu alloy nanoparticles, where Cu incorporation induces both geometric isolation of Ni ensembles and electronic modulation of surface active sites, thereby suppressing condensation-derived by-products. In addition, an NH3/ethanol-assisted process further improves selectivity while reducing autogenous operating pressure. Overall, this work demonstrates a safe and highly selective catalytic system for primary diamine synthesis, providing a practical alternative to conventional Raney Ni-based processes.
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International Journal of Nanomedicine
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2015
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IF 4.383
Zhenzhen Liu,Haijun Gong,Rui Zeng,Xuan Liang,Li-Ming Zhang,Liqun Yang,Yuqing Lan
A hyperbranched cationic polysaccharide derivative-mediated small interfering (si)RNA interference strategy was proposed to inhibit nuclear transcription factor-kappa B (NF-κB) activation in human retinal pigment epithelial (hRPE) cells for the gene therapy of diabetic retinopathy. Two hyperbranched cationic polysaccharide derivatives containing the same amount of cationic residues, but with different branching structures and molecular weights, including 3-(dimethylamino)-1-propylamine-conjugated glycogen (DMAPA-Glyp) and amylopectin (DMAPA-Amp) derivatives, were developed for the efficient delivery of NF-κB siRNA into hRPE cells. The DMAPA-Glyp derivative showed lower toxicity against hRPE cells. Furthermore, the DMAPA-Glyp derivative more readily condensed siRNA and then formed the nanoparticles attributed to its higher branching architecture when compared to the DMAPA-Amp derivative. Both DMAPA-Glyp/siRNA and DMAPA-Amp/siRNA nanoparticles were able to protect siRNA from degradation by nuclease in 25% fetal bovine serum. The particle sizes of the DMAPA-Glyp/siRNA nanoparticles (70–120 nm) were smaller than those of the DMAPA-Amp/siRNA nanoparticles (130–180 nm) due to the higher branching architecture and lower molecular weight of the DMAPA-Glyp derivative. In addition, the zeta potentials of the DMAPA-Glyp/siRNA nanoparticles were higher than those of the DMAPA-Glyp/siRNA nanoparticles. As a result, siRNA was much more efficiently transferred into hRPE cells using the DMAPA-Glyp/siRNA nanoparticles rather than the DMAPA-Amp/siRNA nanoparticles. This led to significantly high levels of suppression on the expression levels of NF-κB p65 messenger RNA and protein in the cells transfected with DMAPA-Glyp/siRNA nanoparticles. This work provides a potential approach to promote hyperbranched polysaccharide derivatives as nonviral siRNA vectors for the inhibition of NF-κB activation in hRPE cells.
研究领域:
药理学
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分子生物学
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眼科学
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基因治疗
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