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DEM modeling of high shear wet granulation of a simple system

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Asian Journal of Pharmaceutical sciences 2018年第3期13卷 220-228页

作者： Saurabh Sarkar Bodhisattwa Chaudhuri Department of Pharmaceutical sciences University of Connecticut Institute of Material Sciences University of Connecticut

High shear wet granulation(HSWG) is one of the most poorly understood processes with known difficulties in optimization and scale up. The purpose of the current study is to develop a DEM model which can be applied under dynamic process conditions with high predictive capacity to improve process insight. The DEM model is used to predict agglomeration as a function of impeller speed and liquid addition rate in a high shear wet granulator. The DEM model tracks dynamic formation and breakage of liquid bridges between particles as liquid binder in the system is added, and corrects for the change in material properties as a function of the binder content.

关键词： High shear wet granulation Discrete element method Capillary bridge model

Preparation of waterborne polyurethane/β-cyclodextrin composite nanosponge by ion condensation method and its application in removing of dyes from wastewater

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Chinese Journal of Chemical Engineering 2023年第6期58卷 124-136页

作者： Shanghong Ma Haitao Zhang Jianbo Qu Xiuzhong Zhu Qingfei Hu Jianyong Wang Peng Ye Futao Sai Shiwei Chen State Key Laboratory of Biobased material and Green Papermaking Qilu University of TechnologyShandong Academy of SciencesJinan 250353China institute of material Science and Technology Qilu University of TechnologyShandong Academy of SciencesJinan 250353China

Currently,polymer nanosponges have received extensive attention.However,developing new synthetic techniques for novel nanosponges remains a challenge.Furthermore,to date,composite nanosponge adsorbents based on waterborne polyurethane(WPU)andβ-cyclodextrin(β-CD)have not been reported.Herein,a novel green method,ion condensation method,was developed in this study for the preparation of polymer nanosponge adsorbents for efficient removal of dyes from wastewater.Based on the principle of charge repulsion between nanoparticles to maintain emulsion stability,waterborne polyurethane/β-cyclodextrin composite nanosponges(WPU-x,y)were prepared by coagulating the emulsions synthesized from 2,2-dimethylolpropionic acid,polypropylene glycol and hexamethylene diisocyanate as raw materials in a mixture of hydrochloric acid and anhydrous ethanol.The structure and appearance of WPU-x,y were characterized by attenuated total reflectance Fourier transform infrared spectroscopy,thermal gravimetric analyzer,scanning electron microscope and mercury intrusion porosimetry.The adsorption capacity of WPU-x,y was tested by parameters such as cross-linking degree,β-CD dosage,contact time,initial dye concentration and p H value.The study found that WPU-4,4.62 had the best adsorption effect on methylene blue(MB),the maximum removal rate was 93.42%,and the maximum adsorption capacity was 136.03 mg·g^(-1).Moreover,the Sips isotherm and pseudo-second-order-model were suitable for MB adsorption.Therefore,this study provides some perspectives for the fabrication of nanosponge adsorbents.

关键词： Ion condensation Composites Nanomaterials Waterborne polyurethane(WPU) β-Cyclodextrin(β-CD) Adsorption

Silicon-based optoelectronic heterogeneous integration for optical interconnection

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Chinese Physics B 2024年第2期33卷 1-9页

作者：李乐良李贵柯张钊刘剑吴南健王开友祁楠刘力源 institute of Semiconductors Chinese Academy of SciencesBeijing 100083China Center of material Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The performance of optical interconnection has improved dramatically in recent years.Silicon-based optoelectronic heterogeneous integration is the key enabler to achieve high performance optical interconnection,which not only provides the optical gain which is absent from native Si substrates and enables complete photonic functionalities on chip,but also improves the system performance through advanced heterogeneous integrated packaging.This paper reviews recent progress of silicon-based optoelectronic heterogeneous integration in high performance optical interconnection.The research status,development trend and application of ultra-low loss optical waveguides,high-speed detectors,high-speed modulators,lasers and 2D,2.5D,3D and monolithic integration are focused on.

关键词： silicon-based heterogeneous integration heterogeneous integrated materials heterogeneous integrated packaging optical interconnection

Surface charge induced tuning of electrical properties of CVD assisted graphene and functionalized graphene sheets

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Journal of materials Science & Technology 2019年第1期35卷 151-158页

作者： Manash Jyoti Deka Devasish Chowdhury material Nanochemistry Laboratory Physical Sciences Division Institute of Advanced Study in Science and Technology

We demonstrate a new approach to tune the electrical properties of graphene and functionalized graphene. Graphene was synthesized using thermal chemical vapour deposition(TCVD) method on copper foil using precursor gas acetylene and co-catalyst H2 gas. TCVD assisted graphene was successfully transferred onto a silicon wafer. Transferred graphene sheet was then functionalized to prepare graphene oxide(GO) and reduced graphene oxide(rGO). Different surface charge carbon nanoparticles, e.g. carbon nanoparticle with net positive charge and carbon nanoparticle with net negative charge were then immobilized on transferred graphene and functionalized graphene sheets. The functionalized graphene and charge mobilized functionalized graphene were characterized by Uv–vis spectroscopy,Fourier transformed infrared spectroscopy, scanning electron microscopy, and Raman spectroscopy. After immobilization of carbon nanomaterials, the ac electrical conductivity was found to increase due to enhancement of the surface charge, electron density, and mobility. It was observed that negative surface charge immobilized graphene and functionalized graphene show higher conductivity. Thus, the electrical property of graphene and functionalized graphene can be tuned by surface modification with different surface charge carbon nanomaterials.

关键词： Graphene Chemical Vapour Deposition (CVD) Surface charge

Low Temperature Synthesis of Nano Porous 12CaO?7Al_2O_3 Powder by Hydrothermal Method

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Journal of Wuhan University of Technology(materials Science) 2016年第6期31卷 1201-1205页

作者： Karim Khan 李佳 ZOU Wenwei XU Wei YANG Ye SONG Weijie Ningbo institute of material Technology and Engineering Chinese Academy of Sciences

Single-phase insulating 12CaO？7Al_2O_3（C12A7） powder was synthesized using an optimized hydrothermal method. Pure phase of C12A7 was got at a comparatively lower temperature（c.a. 300 ℃） than that has been previously reported. The crystallite size of the synthesized C12A7 powder was 7±2 nm. The surface area values calculated for all the samples at a synthesis temperature range of 250-800 ℃ for 5 h were in the range of about 19-24 m^2/g, with pore sizes of 12-20 nm. This low-temperature-based synthetic strategy along with nano porous structures and a high surface area value can facilitate catalyst application.

关键词： C12A7 hydrothermal method low temperature nano pore

Low generational polyamidoamine dendrimers to enhance the solubility of folic acid:A‘‘dendritic effect’’investigation

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Chinese Chemical Letters 2014年第5期25卷 815-818页

作者： Yong Zhang Mei-Ying Xu Tie-Kun Jiang Wei-Zhe Huang Jiang-Yu Wu School of material sciences & Engineering Wuhan Institute of Technology

Low generational（G0–G2,G for generation） polyamidoamine（PAMAM） dendrimers were investigated as enhancers to improve the aqueous solubility of folic acid at pH 11 and pH 5.In these two cases,the solubility of folic acid increases with both the dendrimer concentration and generation.However,the solubilization mechanism is different.The electrostatic interaction between the primary amines of dendrimers and the ionized carboxylic groups of folic acid dominates the dissolution process at pH 11 while the increase of the solubility of folic acid at pH 5 is attributed to the hydrophobic encapsulation inside the dendrimer molecules.In addition,for comparison ethylenediamine was used as a small molecule control to examine the ‘‘dendritic effect＇＇ in the dendrimer-related solubilization process.Interestingly,PAMAM dendrimers exhibit,at pH 5,a significant superiority over ethylenediamine in enhancing solubility,whereas this ‘‘dendritic effect＇＇ cannot be observed under the basic condition.

关键词： Polyamidoamine Dendrimer Folic acid Electrostatic interaction Hydrophobic encapsulation

Ir0/graphdiyne atomic interface for selective epoxidation

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National Science Review 2023年第8期10卷 173-179页

作者： Zhiqiang Zheng Lu Qi Yaqi Gao Xiaoyu Luan Yurui Xue Feng He Yuliang Li Shandong Provincial Key Laboratory for Science of material Creation and Energy Conversion Science Center for Material Creation and Energy Conversion School of Chemistry and Chemical EngineeringShandong University CAS Key Laboratory of Organic Solids Institute of ChemistryChinese Academy of Sciences School of Chemical sciences University of Chinese Academy of Sciences

The development of catalysts that can selectively and efficiently promote the alkene epoxidation at ambient temperatures and pressures is an important promising path to renewable synthesis of various chemical products. Here we report a new type of zerovalent atom catalysts comprised of zerovalent Ir atoms highly dispersed and anchored on graphdiyne(Ir0/GDY) wherein the Ir0is stabilized by the incomplete charge transfer effect and the confined effect of GDY natural cavity. The Ir0/GDY can selectively and efficiently produce styrene oxides(SO) by electro-oxidizing styrene(ST) in aqueous solutions at ambient temperatures and pressures with high conversion efficiency of ～100%, high SO selectivity of 85.5%, and high Faradaic efficiency(FE) of 55%. Experimental and density functional theory(DFT) calculation results show that the intrinsic activity and stability due to the incomplete charge transfer between Ir0and GDY effectively promoted the electron exchange between the catalyst and reactant molecule, and realized the selective epoxidation of ST to SO. Studies of the reaction mechanism demonstrate that Ir0/GDY proceeds a distinctive pathway for highly selective and active alkene-to-epoxide conversion from the traditional processes. This work presents a new example of constructing zerovalent metal atoms within the GDY matrix toward selective electrocatalytic epoxidation.

关键词： graphdiyne atom catalyst atomic interface selective epoxidation high-performance

Strain in perovskite solar cells: origins, impacts and regulation

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National Science Review 2021年第8期8卷 39-56页

作者： Jinpeng Wu Shun-Chang Liu Zongbao Li Shuo Wang Ding-Jiang Xue Yuan Lin Jin-Song Hu Beijing National Laboratory for Molecular sciences(BNLMS) Institute of ChemistryChinese Academy of Sciences School of Chemical sciences University of Chinese Academy of Sciences School of material and Chemical Engineering Tongren University

Metal halide perovskite solar cells(PSCs) have seen an extremely rapid rise in power conversion efficiencies in the past few years. However, the commercialization of this class of emerging materials still faces serious challenges, one of which is the instability against external stimuli such as moisture, heat and irradiation.Much focus has deservedly been placed on understanding the different origins of intrinsic instability and thereby enhancing their stability. Among these, tensile strain in perovskite films is an important source of instability that cannot be overcome using conventionally extrinsic stabilization approaches such as encapsulation. Here we review recent progress in the understanding of the origin of strain in perovskites as well as its corresponding characterization methods, and their impacts on the physical properties of perovskites and the performance of PSCs including efficiency and stability. We then summarize the latest advances in strain-regulation strategies that improve the intrinsic stability of perovskites and photovoltaic devices. Finally, we provide a perspective on how to make further progress in stable and high-efficiency PSCs via strain engineering.

关键词： perovskite stress strain stability solar cells

Non-contact real-time detection of trace nitro-explosives by MOF composites visible-light chemiresistor

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National Science Review 2022年第10期9卷 188-195页

作者： Wei-Hua Deng Ming-Shui Yao Min-Yi Zhang Masahiko Tsujimoto Kenichi Otake Bo Wang Chun-Sen Li Gang Xu Susumu Kitagawa State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences University of Chinese Academy of sciences Chinese Academy of Sciences institute for Integrated Cell-material sciences (WPI-i Ce MS) Kyoto University Institute for Advanced Study Kyoto University institute for Integrated Cell-material sciences (WPI-iCeMS) Kyoto University Institute for Advanced Study Kyoto University Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion materials Key Laboratory of Cluster Science Ministry of Education School of Chemistry and Chemical Engineering Beijing Institute of Technology Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China

To create an artificial structure to remarkably surpass the sensitivity,selectivity and speed of the olfaction system of animals is still a daunting challenge.Herein,we propose a core-sheath pillar(CSP) architecture with a perfect synergistic interface that effectively integrates the advantages of metal-organic frameworks and metal oxides to tackle the above-mentioned challenge.The sheath material,NH2-MIL-125,can concentrate target analyte,nitro-explosives,by 1012 times from its vapour.The perfect band-matched synergistic interface enables the TiO2core to effectively harvest and utilize visible light.At room temperature and under visible light,CSP(TiO2,NH2-MIL-125) shows an unexpected self-promoting analyte-sensing behaviour.Its experimentally reached limit of detection(～0.8 ppq,hexogeon) is 103 times lower than the lowest one achieved by a sniffer dog or all sensing techniques without analyte pre-concentration.Moreover,the sensor exhibits excellent selectivity against commonly existing interferences,with a short response time of 0.14 min.

关键词： MOFs metal oxides electrical devices thin films gas sensors