Phase diagram prediction of recycling aqueous two-phase systems formed by a light-sensitive copolymer and dextran

Zhihua Shao,Fanqi Kong,Xuejun Cao 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.1

Our Laboratory has synthesized a novel light-sensitive and recycling copolymer PNBC. The PNBC copolymer could form recycling aqueous two-phase systems with Dextran. Recycling aqueous two-phase systems have important application in bioseparation engineering. Phase diagram prediction of the novel aqueous two-phase systems also is an important aspect in engineering. This article applied the Cabezas model and effective excluded volume (EEV) model to the experimental data of light-sensitive recycling aqueous two-phase systems. It has been found that the EEV model could consist with experimental data very well. The maximum absolute error and average absolute error is 0.81% (wt%) and 0.23% (wt%), respectively.

α-Amylase로 전분 가수분해를 위한 PEG/Dextran 수성 2상계 구성

박병춘,임동준 한국산업미생물학회 1992 한국미생물·생명공학회지 Vol.20 No.2

Polyethylene glycol/dextran 수성 2상계에서 polyethylene glycol의 분자량과 농도가 증가할수록 체적비는 증가하고 분배계수는 감소하였다. 또한 dextran의 분자량이 증가할수록 체적비는 감소하고 분배계수는 증가하였다. 한편 dextran의 농도가 증가할수 록 체적비와 분배계수는 감소하였다. Bacillus amyloliquefaciens IFO 14141로부터 생산된 α-amylase를 이용하여 polyethylene glyco1/dextran 수성 2상계에서 가용성 전분의 연속당화를 수행하였다. 이 system에서 미반응 starch와 α-amylase를 재이용할 수 있었다. 즉 α-amylase를 settler의 하층으로부터 reactor로 회수하여 재이용함으로서 α-amylase의 활성을 100시간 이상 유지할 수 있었다. In the polyethylene glycol/dextran aqueous two-phase systems, volume ratio was increased and partition coefficient was decreased with the increase of polyethylene glycol molecular weight and concentration. However the volume ratio was decreased and the partition coefficient was increased with the increase of dextran molecular weight. On the other hand, the volume ratio and the partition coefficient were decreased with the increase of dextran concentration. Continuous enzymatic hydrolysis of soluble starch with α-amylase which was produced by Bacillus amyloliquefaciens IFO 14141 was investigated in polyethylene glycol/dextran aqueous two-phase systems. Nonreacted soluble starch and α-amylase were reused in these systems. α-Amylase activity was maintained more than 100 hrs by recycling of α-amylase from bottom of settler to reactor.

다중 층 화장료에서 수성 이상계의 응용

홍준기 ( Junki Hong ),유재원 ( Jaewon You ),유장영 ( Jangyung Yoo ),남승옥 ( Seungok Nam ),이상길 ( Sanggil Lee ),표형배 ( Hyeongbae Pyo ) 대한화장품학회 2013 대한화장품학회지 Vol.39 No.2

수성 이상계는 물에 친수 성분만을 용해시킨 후 용해 물질들 사이에 유발되는 단순한 물리적 불친화성에 의해 액상 다중 층으로 분리되기 때문에 생체적합성에 대한 장점을 가지고 있다. 본 연구에서는 물에 친수 성분만을 용해시킨 후 두 층으로 분리되는 수성 이상계 상분리 원리를 수성 다중 층 액상 화장료에 응용하여 수성다중 층 화장료에 적용이 가능한 대표적인 두 종의 수성 이상계를 선정하였으며, 이들에 대해 바이노달 곡선과 임계점 및 농도 대응선 그리고 새로운 개념의 상분리 부피 및 상분리 시간 대응곡선을 포함하는 상도를 실험을 통해 작성하였으며, 상 도표로부터 액상 다중 층으로 분리되는 최적의 조건을 관찰할 수 있었다. The aqueous two phase system has biocompatibility, because it is physically separated into an immiscible liquid multi-layer induced by incompatibility among hydrophilic components dissolved in the water phase. we have applied this principle to aqueous multi-layer liquid cosmetics and select two representative systems. What it was experimentally obtained was the phase diagrams including a binodal curve, a critical point, tie lines of concentration and tie curves of phase separating volume ratio and phase separating time. From the phase diagrams, we were able to observe existence of the optimum condition to prepare the aqueous multi-layer cosmetics for the systems.

An integrated dendrite-free zinc metal electrode for corrosion inhibition in aqueous system

Yi-Fan Hu,Li-Feng Zhou,He Gong,He Jia,Peng Chen,Yi-Song Wang,Li-Ying Liu,Tao Du 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.9

Zinc ion batteries have gotten increasing attention as a potential candidate for lithium-ion batteries, due totheir high specific capacity (820 mAh·g1), energy density, and safety. Inevitably, dendrite and corrosion create sometrouble for this system. Herein, an integrated Zn electrode coated by Zn-Al metal oxides prepared by a simple spincoatingmethod was utilized to increase the rechargeability for aqueous zinc ion batteries. By coating the Zn anodewith an artificial electrolyte interface, the wettability of Zn anodes was improved and impedance was reduced. Thecoating suppressed not only the appearance of dendrite but also the formation of corrosion products. The symmetricalcells with coating have a low overpotential (43mV) and an excellent life span. Meanwhile, the applied full batteriesexhibit an improved capacity retention rate (86.67% after 120 cycles), great rate performance and low apparent activationenergy (24.6 KJ·mol1). The simple production methods and superior corrosion suppression effects provide newideas for the anode protection of aqueous system batteries.

Extractive bioconversion of xylan for production of xylobiose and xylotriose using a PEG6000/sodium citrate aqueous two-phase system

Xin Li,Zhina Lian,Bo Dong,Yong Xu,Qiang Yong,Shiyuan Yu 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.9

Aqueous two-phase system (ATPS) was applied for extraction bioconversion of xylan by xylanase from Trichoderma viride. Phase diagrams for poly (ethylene glycol) (PEG) and sodium citrate were determined at room temperature. The ATPS composed of 12.99% (w/w) PEG6000 and 12.09% (w/w) sodium citrate was favorable for partition of xylanase and used for extraction bioconversion of xylan. Batch hydrolysis demonstrated that higher concentrations of xylobiose and xylotriose were obtained in the PEG6000/sodium citrate ATPS compared to those in the aqueous system. These results present the potential feasibility of production of xylo-oligosaccharides by extraction bioconversion in ATPS.

Salting-out Effects on the Partition of Proteins in Aqueous Two-phase Systems

( Chan Wha Kim ),( Kyun Rha Cho ) 한국미생물생명공학회 1996 Journal of microbiology and biotechnology Vol.6 No.5

Kinetics of Horseradish Peroxidase-Catalyzed Nitration of Phenol in a Biphasic System

( Mingming Kong ),( Yang Zhang ),( Qida Li Runan Dong ),( Haijun Gao ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.2

The use of peroxidase in the nitration of phenols is gaining interest as compared with traditional chemical reactions. We investigated the kinetic characteristics of phenol nitration catalyzed by horseradish peroxidase (HRP) in an aqueous-organic biphasic system using n-butanol as the organic solvent and NO₂ - and H₂O₂ as substrates. The reaction rate was mainly controlled by the reaction kinetics in the aqueous phase when appropriate agitation was used to enhance mass transfer in the biphasic system. The initial velocity of the reaction increased with increasing HRP concentration. Additionally, an increase in the substrate concentrations of phenol (0-2 mM in organic phase) or H₂O₂ (0-0.1 mM in aqueous phase) enhanced the nitration efficiency catalyzed by HRP. In contrast, high concentrations of organic solvent decreased the kinetic parameter V_max/K_m. No inhibition of enzyme activity was observed when the concentrations of phenol and H₂O₂ were at or below 10 mM and 0.1 mM, respectively. On the basis of the peroxidase catalytic mechanism, a double-substrate ping-pong kinetic model was established. The kinetic parameters were K_m ^H2O2 = 1.09 mM, K_m ^PhOH = 9.45 mM, and V_max = 0.196 mM/min. The proposed model was well fit to the data obtained from additional independent experiments under the suggested optimal synthesis conditions. The kinetic model developed in this paper lays a foundation for further comprehensive study of enzymatic nitration kinetics.

박테리오신 신속 추출을 위한 Aqueous Two Phase System 고찰

김종희 ( Jong-hui Kim ),이은선 ( Eun-seon Lee ),김부민 ( Bu-min Kim ),함준상 ( Jun-sang Ham ),오미화 ( Mi-hwa Oh ) 한국산업식품공학회 2021 산업 식품공학 Vol.25 No.4

Bacteriocins are ribosomally synthesized proteinaceous substances produced by bacteria. They exhibit antimicrobial activity against closely related species and food-borne pathogens. Those produced by lactic acid bacteria (LAB) suggest a new direction for food preservation as they are often employed in food processing and food fermentations as natural biopreservatives. However, this new market demands the development of new downstream strategies to maximize its efficiency and economics. Aqueous two-phase system (ATPS) is a liquid-liquid fractionation technique, which has emerged as a powerful tool for the efficient extraction and purification of peptides, enzymes, and proteins due to its versatility, lower cost, process integration capability, and ease to scale-up. In this review, we introduce polymer-salt ATPS and surfactant-assisted ATPS for bacteriocin separation and provide an overview of the effects of parameters such as tie line length, pH, and properties of polymers and salts.

Modeling of the phase equilibria of aqueous two-phase systems using three-dimensional neural network

Hui-Chao Lv,Da Yong Tian 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.1

A three-dimensional neural network model has been designed for representing the phase equilibrium data related to aqueous two-phase systems. The polyvinyl pyrrolidone/phosphate/water system was selected as the model system to demonstrate the point of interest. The collected experimental data were categorized into two subsets, training and validation sets, not only to find the suitable network configuration but also to prevent the overfitting problem. Meanwhile, the weight comparison method was proposed to optimize the three-dimensional neural net. The results of accuracy comparison indicate that it outperforms the two-dimensional neural network on some details and can further enhance the calculation accuracy of the phase equilibrium data for these investigated aqueous two-phase systems. The development of the neural network in the three-dimensional space should be a research project of concern.

Synthesis and Application of a Light-sensitive Polymer Forming Aqueous Two-phase Systems

Kong FanQi,Cao Xuejun,Xia Jinan,허병기 한국공업화학회 2007 Journal of Industrial and Engineering Chemistry Vol.13 No.3

Abstract:A visible light-sensitive polymer that forms aqueous two-phase systems has been synthesized by using N-isopropylacrylamide, n-butyl acrylate, and chlorophyllin sodium copper salt as monomers, and its capability to form aqueous two-phase system was investigated. The polymer formed aqueous two-phase systems with Dextran20000. Over 98 % of the polymer could be recovered by using light radiation at 488 nm. The recovery experiments were repeated five times. The recoveries were maintained fairly stable. The polymer could be recovered at more than 95 % by using thermo separation. Trypsin constantly maintained a relatively high activity and stability in the aqueous two-phase systems.