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微胶囊 1

控制释放 1

泵送性能 1

海藻酸钙 1

肠靶向递送 1

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Development of barium@alginate adsorbents for sulfate removal in lithium refining

Lisa Xu, Kaifei Chen, George Q. Chen, Sandra E. Kentish, Gang (Kevin) Li

《化学科学与工程前沿(英文)》 2021年 第15卷 第1期   页码 198-207 doi: 10.1007/s11705-020-1968-z

摘要: The demand for lithium has been steadily growing in recent years due to the boom of electric cars. High purity lithium is commonly used in the manufacture of battery grade lithium electrolyte. Sulfate residuals originating from acid leaching of lithium ores must be limited to below 20 mg·L during refining. There are methods to remove sulfate such as membrane processing and chemical precipitation using barium salts. However, membrane separation is unable to achieve the required purity while chemical precipitation often causes secondary contamination with barium and requires extra filtration processes that lead to increased processing costs. In this study, we developed a polymeric matrix entrapped with barium ions as a novel adsorbent to selectively adsorb sulfate in aqueous solutions. The adsorbent was prepared by dropwise injection method where alginate droplets were crosslinked with barium to form hydrogel microcapsules. In a typical scenario, the microcapsules had a diameter of 3 mm and contained 5 wt-% alginate. The microcapsules could successfully reduce sulfate concentration in a solution from 100 to 16 mg·L , exceeding the removal target. However, the microcapsules were mechanically unstable in the presence of an excess amount of sulfate. Hence, calcium ions were added as a secondary crosslinking agent to improve the integrity of the microcapsules. The two-step Ca/Ba@alginate microcapsules showed an exceptional adsorption performance, reducing the sulfate concentration to as low as 0.02 mg·L . Since the sulfate selective microcapsules can be easily removed from the aqueous system and do not result in secondary barium contamination, these Ca/Ba@alginate adsorbents will find applications in ultra-refining of lithium in industry.

关键词: barium@alginate     microcapsules     dropwise injection     sulfate removal     lithium    

Immobilization and characterization of the mycelia-embedded polylysine-alginate beads and their decolorization

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2001-2013 doi: 10.1007/s11705-023-2341-9

摘要: Liquid fermented fungal mycelia with decolorization capability have potential applications in scale-up. In this work, the Lactarius deliciosus mycelia were immobilized on -polylysine-alginate beads, and the decolorization effects of -polylysine-alginate beads were demonstrated along with Coomassie brilliant blue G-250 as a model dye. Morphology observation confirmed the beads had an exterior film and interior capsule with honeycomb microstructures suitable for mycelia growth. It was manifested that the maximum decolorization efficiency for mycelia was 98.5% at a removal rate of 0.68 mg·L‒1·h after 3 days. In comparison, the decolorization efficiency of the immobilized mycelia reached the maximum value of 97.3% at a removal rate of 6.1 mg·L‒1·h after 8 h. The enzyme activities of lignin peroxidase and laccase tested in the immobilized mycelia were significantly higher than in that of the free ones, such as the lignin peroxidase had the highest enzyme activity of 77.6 ± 7.4 U·L‒1 in the former, while of 27.4 ± 8.7 U·L‒1 in the latter. The immobilization of L. deliciosus mycelia could improve the decolorization of Coomassie brilliant blue G-250 efficiently. The prepared -polylysine-alginate beads embedded with L. deliciosus mycelia have very good reusability and a great potential in decolorizing analog dyes.

关键词: Lactarius deliciosus mycelia     immobilization     decolorization     polylysine-alginate beads     Coomassie brilliant blue G-250    

Nanosilver anchored alginate/poly(acrylic acid/acrylamide) double-network hydrogel composites for efficient

《化学科学与工程前沿(英文)》 2023年 第17卷 第7期   页码 893-905 doi: 10.1007/s11705-022-2290-8

摘要: A novel alginate/poly(acrylic acid/acrylamide) double-network hydrogel composite with silver nanoparticles was successfully fabricated using the sol–gel method. The presence of carboxyl and amide groups in the network structure provided abundant active sites for complexing silver ions, facilitating the in situ reduction and confinement of silver nanoparticles. In batch experiments, the optimal silver loading was 20%, and 5 mmol·L–1 of p-nitrophenol was completely degraded in 113 s with a rate constant value of 4.057 × 10−2 s–1. In the tap water system and simulated seawater system, the degradation time of p-nitrophenol at the same concentration was 261 and 276 s, respectively, with a conversion rate above 99%. In the fixed-bed experiment, the conversion rate remained above 74% after 3 h at a flowing rate of 7 mL·min–1. After 8 cycling tests, the conversion rate remained at 98.7%. Moreover, the catalyst exhibited outstanding performance in the degradation experiment of four typical organic dyes.

关键词: double-network hydrogel     dye degradation     silver nanoparticles     alginate    

Dielectric property of polyimide/barium titanate composites and its influence factors (II)

LIU Weidong, ZHU Baoku, XIE Shuhui, XU Zhikang

《化学科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 417-421 doi: 10.1007/s11705-008-0078-0

摘要: Using poly(amic acid) (PAA) as a precursor followed by thermal imidization, the polyimide/barium titanate composite films were successfully prepared by a direct mixing method and in situ process. The influence of processing factors, such as particle size, distribution mode and polymerization method on dielectric properties was studied. Results revealed that the dielectric constant (?) of the composite film increased by using bigger fillers or employing in situ polymerization and bimodal distribution. When the composite film containing 50 Vol-% of BaTiO with size in 100 nm was prepared via in situ process, its dielectric constant reached 45 at 10 kHz.

关键词: thermal imidization     dielectric constant     particle     precursor     titanate composite    

Numerical investigation of the influence of kinetics and shape factor on barium sulfate precipitation

Zheng WANG, Zai-Sha MAO, Chao YANG, Qinghua ZHANG, Jingcai CHENG

《化学科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 272-281 doi: 10.1007/s11705-009-0023-x

摘要: The effect of kinetics and shape factor on barium sulfate precipitation in a continuous stirred tank has been investigated numerically through solving the standard momentum and mass transport equations in combination with the moment equations for crystal population balance. The numerical method was validated with the literature data. The simulated results include the distribution of the local supersaturation ratio in the reactor, the mean crystal size, and the coefficient of variation. The simulation results show that the value of shape factor used in the model affected greatly the mean crystal size and the moments of the crystal size distribution. The influence of the kinetic expressions on the simulation is also analyzed. It is important to investigate the relationship of the shape factor with the precipitator type and other operation conditions to obtain reliable simulation results and suitable kinetic equations of crystal nucleation and growth rates.

关键词: stirred tank     numerical simulation     precipitation     shape factor     crystal kinetics    

Dual cross-linked MXene/cellulose nanofiber/nickel alginate film with improved mechanical properties

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1460-1469 doi: 10.1007/s11705-023-2335-7

摘要: Electromagnetic interference pollution has raised urgent demand for the development of electromagnetic interference shielding materials. Transition metal carbides (MXenes) with excellent conductivity have shown great potential in electromagnetic interference (EMI) shielding materials, while the poor mechanical strength, flexibility, and structural stability greatly limit their further applications. Here, cellulose nanofibers and sodium alginate are incorporated with MXene nanosheets as flexible matrices to construct strong and flexible mussel-like layered MXene/Cellulose nanofiber/Sodium Alginate composite films, and nickel ions are further introduced to induce metal coordination crosslinking of alginate units. Benefited from the dual-crosslinked network structure of hydrogen bonding and metal coordination, the tensile strength, Young’s modulus, and toughness of the MXene/cellulose nanofiber/nickel alginate composite film are significantly increased. After subsequent reduction by ascorbic acid, excess nickel ions are reduced to nickel nanoparticles and uniformly dispersed within the highly conductive composite film, which further improved its hysteresis loss effect toward the incident electromagnetic waves. Consequently, the MXene/cellulose nanofiber/nickel alginate-Ni composite film presents a considerably enhanced electromagnetic interference shielding effectiveness (47.17 dB) at a very low thickness of 29 μm. This study proposes a feasible dual-crosslinking and subsequent reduction strategy to synergistically enhance the mechanical properties and electromagnetic interference shielding performance of MXene-based composite materials.

关键词: Ti3C2Tx MXene     double crosslinking     mechanical properties     EMI shielding performance    

Boron and nitrogen co-doped porous carbon derived from sodium alginate enhanced capacitive deionization

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2014-2024 doi: 10.1007/s11705-023-2346-4

摘要: Capacitive deionization can alleviate water shortage and water environmental pollution, but performances are greatly determined by the electrochemical and desalination properties of its electrode materials. In this work, B and N co-doped porous carbon with micro-mesoporous structures is derived from sodium alginate by a carbonization, activation, and hydrothermal doping process, which exhibits large specific surface area (2587 m2·g‒1) and high specific capacitance (190.7 F·g‒1) for adsorption of salt ions and heavy metal ions. Furthermore, the materials provide a desalination capacity of 26.9 mg·g−1 at 1.2 V in 500 mg·L‒1 NaCl solution as well as a high removal capacity (239.6 mg·g‒1) and adsorption rate (7.99 mg·g‒1·min‒1) for Pb2+ with an excellent cycle stability. This work can pave the way to design low-cost porous carbon with high-performances for removal of salt ions and heavy metal ions.

关键词: capacitance deionization     porous carbon     B/N co-doping     heavy metal ions     water purification    

Mercury removal and recovery by immobilized

Meifang CHIEN, Ryo NAKAHATA, Tetsuya ONO, Keisuke MIYAUCHI, Ginro ENDO

《化学科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 192-197 doi: 10.1007/s11705-012-1284-3

摘要: From several mercury removing microorganisms, we selected MB1, which is non-pathogenic, broad-spectrum mercury resistant, mercuric ion reducing, heat tolerant, and spore-forming, as a useful bacterium for bioremediation of mercury pollution. In this study, mercury removal performance of the immobilized MB1 was investigated to develop safe, efficient and stable catalytic bio-agent for mercury bioremediation. The results showed that the alginate gel immobilized MB1 cells efficiently removed 80% of mercury from the solution containing 10 mg/L mercuric chloride within 24 h. These cells still had high activity of mercury removal even after mercuric ion loading was repeated for nine times. The analysis of mercury contents of the alginate beads with and without immobilized MB1 suggested that a large portion of reduced metallic mercury was trapped in the gel beads. It was concluded that the alginate gel immobilized MB1 cells have potential to remove and recover mercury from mercury-containing water.

关键词: mercury removal     immobilized bacteria     alginate gel     bioremediation    

具有泵送控释性能的肠靶向Janus型双腔室海藻酸钙基微胶囊 Article

温霜, 巨晓洁, 刘文英, 刘玉琼, 蒲兴群, 刘壮, 汪伟, 谢锐, Yousef Faraj, 褚良银

《工程(英文)》 2023年 第24卷 第5期   页码 114-125 doi: 10.1016/j.eng.2022.05.021

摘要:

本文成功开发了一种具有泵送控释特性的θ形双腔室肠靶向海藻酸钙基微胶囊,囊壁为海藻酸钙-壳聚糖/精蛋白/二氧化硅(ACPSi)复合壳,为封装的药物在胃环境中提供了良好保护,实现药物的肠靶向释放。该θ形微胶囊由含药室和助推室两个腔室组成:含药室负载疏水药物吲哚美辛,其囊壁内嵌肠溶性
羟丙甲基纤维素邻苯二甲酸酯(HPMCP)微球,作为“微阀门”(micro-valves);助推室包封助推剂聚丙烯酸(PAA),在肠液环境中,PAA发生溶胀,可提高吲哚美辛释放速率。结果显示,载药的θ-ACPSi 微胶囊在模拟胃液(pH值为2.5)中,吲哚美辛的释放率小于1%。然而,进入模拟肠液(pH值为6.8)时,含药室囊壁中的HPMCP微球溶解,释药“微通道”(microchannel)被打开,同时助推室中的PAA发生溶胀,为药物的释放提供推动力。结果,吲哚美辛在小肠中以恒定的速度释放60%以上。因此,该θ-ACPSi 微胶囊具有良好的泵送和肠靶向控释性能,为口服肠道靶向给药系统的开发提供了一种新策略。

关键词: 微胶囊     海藻酸钙     肠靶向递送     泵送性能     控制释放    

Effect of effluent organic matter on ozonation of bezafibrate

Huan HE,Qian SUI,Shuguang LU,Wentao ZHAO,Zhaofu QIU,Gang YU

《环境科学与工程前沿(英文)》 2015年 第9卷 第6期   页码 962-969 doi: 10.1007/s11783-015-0772-3

摘要: The influence of three effluent organic matter (EfOM) model compounds, humic acid (HA), bovine serum albumin (BSA), and sodium alginate (AGS), on the ozonation of bezafibrate (BF), a typical pharmaceutical and personal care product (PPCP), was investigated. The results show that ozonation efficiently removed BF from aqueous solution with removal efficiencies>95% within 8 min for all conditions. The reaction rate of BF decreased with increasing model compounds concentrations and the influence was more pronounced for HA and BSA, while less pronounced for AGS. Although BF concentration was significantly reduced, the degree of mineralization achieved was only approximately 11%. The addition of HA and BSA improved the mineralization of the solution, while the influence of AGS was minor. The acute toxicity of BF solution during ozonation was determined using the Luminescent bacteria test, and the toxicity exhibited an initial increase and a successive reduction. An overall decreased acute toxicity was observed with an increase of HA. The presence of BSA increased the formation rate of toxicity intermediates and resulted in inhibition peak forward.

关键词: ozonation     bezafibrate     acute toxicity     humic acid     bovine serum albumin     sodium alginate    

标题 作者 时间 类型 操作

Development of barium@alginate adsorbents for sulfate removal in lithium refining

Lisa Xu, Kaifei Chen, George Q. Chen, Sandra E. Kentish, Gang (Kevin) Li

期刊论文

Immobilization and characterization of the mycelia-embedded polylysine-alginate beads and their decolorization

期刊论文

Nanosilver anchored alginate/poly(acrylic acid/acrylamide) double-network hydrogel composites for efficient

期刊论文

Dielectric property of polyimide/barium titanate composites and its influence factors (II)

LIU Weidong, ZHU Baoku, XIE Shuhui, XU Zhikang

期刊论文

Numerical investigation of the influence of kinetics and shape factor on barium sulfate precipitation

Zheng WANG, Zai-Sha MAO, Chao YANG, Qinghua ZHANG, Jingcai CHENG

期刊论文

Dual cross-linked MXene/cellulose nanofiber/nickel alginate film with improved mechanical properties

期刊论文

Boron and nitrogen co-doped porous carbon derived from sodium alginate enhanced capacitive deionization

期刊论文

Mercury removal and recovery by immobilized

Meifang CHIEN, Ryo NAKAHATA, Tetsuya ONO, Keisuke MIYAUCHI, Ginro ENDO

期刊论文

具有泵送控释性能的肠靶向Janus型双腔室海藻酸钙基微胶囊

温霜, 巨晓洁, 刘文英, 刘玉琼, 蒲兴群, 刘壮, 汪伟, 谢锐, Yousef Faraj, 褚良银

期刊论文

Effect of effluent organic matter on ozonation of bezafibrate

Huan HE,Qian SUI,Shuguang LU,Wentao ZHAO,Zhaofu QIU,Gang YU

期刊论文