CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2024
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IF 3.7
Min An,Chengxiang Wang,Qing Liu,Mengya Wang,Zhirong Yang,Wenpeng Li,Guoli Zhou,Jingtao Wang,Jinli Zhang
Combining the advantages of high efficiency, low-pressure drop, and large throughput, the pore array-enhanced tube-in-tube microchannel (PA-TMC) is a promising microreactor for industrial applications. However, most of the mass transfer takes place in the upstream pore region, while the contribution of the downstream annulus is limited. In this work, helical wires were introduced into the annulus by adhering to the outer surface of the inner tube. Mixing behavior and mass transfer of liquid–liquid two-phase flow in PA-TMC with different helical wires have been systematically studied by a combination of experiments and volume of fluid (VOF) method. The introduction of helical wires improves the overall volumetric mass transfer coefficient K L a by up to 133% and the mass transfer efficiency E by up to 117%. The simulation results show that the helical wire brings extra phase mixing regions and increases the specific interface area, while accelerating the fluid flow and expanding the area of enhanced turbulent dissipation rate. Influences of helical wires in various configurations are compared by the comprehensive index I concerning the pressure drop and mass transfer performance simultaneously and a new correlation between K L a and specific energy consumption ϕ is proposed. This research deepens the understanding of the mixing behavior and mass transfer in the PA-TMCs and provides practical experience for the process intensification of microchannel reactors.
研究领域:
化学工程
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传热传质学
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微流控技术
✓ 已验证
产品关联
DOI
高影响因子
BIOMACROMOLECULES
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2018
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IF 5.738
Jingsong Yuan,Yi Zhang,Yue Sun,Zhicheng Cai,Lijiang Yang,Hua Lu
Controlling the helix–coil transition of polypeptides under physiological conditions is an attractive way toward smart functional materials. Here, we report the synthesis of a series of tertiary amine-functionalized ethylene glycol (EGx)-linked polypeptide electrolytes with their secondary structures tunable under physiological conditions. The resultant polymers, denoted as P(EGxDMA-Glu) (x = 1, 2, and 3), show excellent aqueous solubility (>20 mg/mL) regardless of their charge states. Unlike poly-l-lysine that can form a helix only at pH above 10, P(EGxDMA-Glu) undergo a pH-dependent helix–coil switch with their transition points within the physiological range (pH ∼5.3–6.5). Meanwhile, P(EGxDMA-Glu) exhibit an unusual salt-induced helical conformation presumably owing to the unique properties of EGx linkers. Together, the current work highlights the importance of fine-tuning the linker chemistry in achieving conformation-switchable polypeptides and represents a facile approach toward stimuli-responsive biopolymers for advanced biological applications.
研究领域:
生物材料
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高分子化学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Acta Biomaterialia
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2021
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IF 8.947
Wenjun Lu,Sha Wang,Rui Liu,Ying Guan,Yongjun Zhang
Depletion of human serum albumin (HSA), the most abundant protein in human plasma , from serum/plasma is a prerequisite before their proteomic analysis. Molecularly imprinted polymers (MIPs) using HSA as a template have been designed for this purpose, but suffer from a low sorption capacity and low selectivity. Here, a new HSA-imprinted polymer was synthesized using N-isopropylacrylamide (NIPAM) as the main monomer ; acrylamide (AAm), methacrylic acid (MAA), and dimethylaminoethyl methacrylate (DMAEMA) as functional monomers; and oligoglutamic acid-based peptide crosslinker (PC) as a crosslinker at pH 5.5. When pH is adjusted to 7.4, the peptide chains in the polymer change from a helical conformation to an extended coil conformation, and the polymer swells. Consequently, the template protein is removed completely. When pH is adjusted back to 5.5, the peptide chains fold back precisely to the helical conformation. Both the size and shape of the imprint cavities are restored. Therefore, the polymer rebinds the template protein selectively. Highest imprinting factor (IF) was observed at pH 5.5 at which the polymer was synthesized. The IF increases with the increasing number of glutamic acid residues in the PCs because of their increased degree of helicity at pH 5.5. No improvement in imprinting effect was observed when using a peptide crosslinker containing both L- and D-glutamic acid residues and hence incapable of folding into α-helix, further confirming the key role of the pH-induced helix-coil transition of the peptide chains. The MIP synthesized here presents a much higher affinity to HSA than the nontemplate proteins. It could be used repeatedly without evident decrease in sorption capacity. Because of the mild eluting conditions, the secondary structure of the extracted HSA protein remains unchanged. Finally, the MIP was used to deplete HSA from human serum. Because of its high sorption capacity and high selectivity, HSA was depleted completely and selectively. Statement of significance A new molecularly imprinted polymer (MIP) using human serum albumin (HSA) as a template was synthesized using N-isopropylacrylamide (NIPAM) as the main monomer; acrylamide (AAm), methacrylic acid (MAA), and dimethylaminoethyl methacrylate (DMAEMA) as functional monomers; and oligoglutamic acid-based peptide crosslinker as a crosslinker. Because of the reversible and precise pH-induced helix-coil transition of the peptide chains, the template protein was removed facilely and completely under mild conditions. Simultaneously, a significant improvement in imprinting efficiency was obtained. The sorption capacity was as high as 648.05 mg/g and the imprinting factor was 7.9. Because of its high selectivity and high binding capacity, the MIP synthesized here is highly promising for the depletion of HSA, the most abundant protein in serum, which is a prerequisite for its proteomic analysis. For the first time, complete and selective depletion of HSA from human serum was achieved using a protein-imprinted polymer.
研究领域:
生物材料
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蛋白质组学
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高分子科学
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分析化学
✓ 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）