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Density functional theory for molecular orientation of hard rod fluids in hard slits

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Chinese Physics B 2007年第8期16卷 2296-2303页

作者：曹达鹏程礼盛汪文川 division of Molecular and Materials Simulation Key Laboratory of NanomaterialsMinistry of Education Beijing University of Chemical Technology Beijing 100029 China

A density functional theory （DFT） is used to investigate molecular orientation of hard rod fluids in a hard slit. The DFT approach combines a modified fundamental measure theory （MFMT） for excluded-volume effect with the first order thermodynamics perturbation theory for chain connectivity. In the DFT approach, the intra-molecular bonding orientation function is introduced. We consider the effects of molecular length （i.e. aspect ratio of rod） and packing fraction on the orientations of hard rod fluids and flexible chains. For the flexible chains, the chain length has no significant effect while the packing fraction shows slight effect on the molecular orientation distribution. In contrast, for the hard rod fluids, the chain length determines the molecular orientation distribution, while the packing fraction has no significant effect on the molecular orientation distribution. By making a comparison between molecular orientations of the flexible chain and the hard rod fluid, we find that the molecular stiffness distinctly affects the molecular orientation. In addition, partitioning coefficient indicates that the longer rodlike molecule is more difficult to enter the confined phase, especially at low bulk packing fractions.

关键词： density functional theory rodlike chain molecular orientation flexible chain

Dip-coating processed sponge-based electrodes for stretchable Zn-MnO2 batteries

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Nano Research 2018年第3期11卷 1554-1562页

作者： Hong-Wu Zhu Jin Ge Yu-Can Peng Hao-Yu Zhao Lu-An Shi Shu-Hong Yu division of nanomaterials & Chemistry Hefei National Laboratory for Physical Sciences at the Microscale Collaborative Innovation Center of Suzhou Nano Science and Technology Department of Chemistry CAS Centre for Excellence in Nanoscience Hefei Science Centre of CAS University of Science and Technology of China Hefei 230026 China

Stretchable electronics are in high demand for next-generation wearable devices, but their fabrication is still challenging. Stretchable conductors, flexible pressure sensors, and foldable light-emitting diodes （LEDs） have been reported; however, the fabrication of stable stretchable batteries, as power suppliers for wearable devices, is significantly behind the development of other stretchable electronics. Several stretchable lithium-ion batteries and primary batteries have been fabricated, but their low capacities and complicated manufacturing processes are obstacles for practical applications. Herein, we report a stretchable zinc/manganese-oxide （Zn-MnO2） full battery based on a silver-nanowire- coated sponge prepared via a facile dip-coating process. The spongy electrode, with a three-dimensional （3D） binary network structure, provided not only high conductivity and stretchability, but also enabled a high mass loading of electrochemically active materials （Zn and MnO2 particles）. The fabricated Zn-MnO2 battery exhibited an areal capacity as high as 3.6 mAh·cm^-2 and could accommodate tensile strains of up to 100% while retaining 89% of its original capacity. The facile solution-based strategy of dip-coating active materials onto a cheap sponge-based stretchable current collector opens up a new avenue for fabricating stretchable batteries.

关键词： stretchable battery,Zn-MnO2 batter silver nanowires,sponge,binary network structure

A surfactant-free route to synthesize Ba_xSr_(1-x)TiO_3 nanoparticles at room temperature, their dielectric and microwave absorption properties

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Science China Materials 2016年第8期59卷 609-617页

作者：吴庆松刘建伟王广胜陈绍锋俞书宏 division of nanomaterials&Chemistry Hefei National Laboratory for Physical Science atMicroscaleCollaborative Innovation Center of Suzhou Nano Science and TechnologyDepartment of ChemistryUniversity of Science and Technology of ChinaHefei 230026China

Perovskite materials, such as Ba_xSr_(1-x)Ti_O3(BST), have been continuously receiving attentions due to their unique ferroelectric, pyroelectric, dielectric, piezoelectric and electric-optic properties. Here, we report a facile route for the synthesis of BST nanocrystalline materials by fast mixing of MCl_2(M = Ba, Sr) aqueous solution and titanium isopropoxide ethanol solution at room temperature without using any surfactants or structure-directing *** molar ratio of Ba/Sr was controlled by adjusting the original molar ratio of BaCl_2·2H_2O and SrCl_2·6H_2O. The dielectric properties and microwave absorption capability of the BST nanocrystalline were studied. The results indicate that the BST nanocrystalline material has the best dielectric and microwave absorption properties in the case of Ba_(0.7)Sr_(0.3)TiO_3. The present strategy is facile, low cost and high yield, which may provide a new route for the synthesis of other perovskite materials.

关键词： perovskite crystallization dielectric microwave mixed solution

Recent advances in the application of MXenes for neural tissue engineering and regeneration

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Neural Regeneration Research 2024年第2期19卷 258-263页

作者： Menghui Liao Qingyue Cui Yangnan Hu Jiayue Xing Danqi Wu Shasha Zheng Yu Zhao Yafeng Yu Jingwu Sun Renjie Chai State Key Laboratory of Digital Medical Engineering Department of Otolaryngology Head and Neck SurgeryZhongda HospitalSchool of Life Sciences and TechnologyAdvanced Institute for Life and HealthJiangsu Province High-Tech Key Laboratory for Bio-Medical ResearchSoutheast UniversityNanjingJiangsu ProvinceChina Co-Innovation Center of Neuroregeneration Nantong UniversityNantongJiangsu ProvinceChina Department of Oto-Rhino-Laryngology West China HospitalSichuan UniversityChengduSichuan ProvinceChina First Affiliated Hospital of Soochow University SuzhouJiangsu ProvinceChina Department of Otolaryngology-Head and Neck Surgery The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui ProvinceChina Department of Otolaryngology Head and Neck Surgery Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijingChina Beijing Key Laboratory of Neural Regeneration and Repair Capital Medical UniversityBeijingChina

Transition metal carbides and nitrides(MXenes)are crystal nanomaterials with a number of surface functional groups such as fluorine,hydroxyl,and oxygen,which can be used as carriers for proteins and *** have excellent biocompatibility,electrical conductivity,surface hydrophilicity,mechanical properties and easy surface ***,at present,the stability of most MXenes needs to be improved,and more synthesis methods need to be *** are good substrates for nerve cell regeneration and nerve reconstruction,which have broad application prospects in the repair of nervous system *** the application of MXenes in neuroscience,mainly at the cellular level,the long-term in vivo biosafety and effects also need to be further *** review focuses on the progress of using MXenes in nerve regeneration over the last few years;discussing preparation of MXenes and their biocompatibility with different cells as well as the regulation by MXenes of nerve cell regeneration in two-dimensional and three-dimensional environments in *** have great potential in regulating the proliferation,differentiation,and maturation of nerve cells and in promoting regeneration and recovery after nerve *** addition,this review also presents the main challenges during optimization processes,such as the preparation of stable MXenes and long-term in vivo biosafety,and further discusses future directions in neural tissue engineering.

关键词： hydrogels MXenes nerve regeneration neural cells neural stem cells organoids spiral ganglion neurons

In situ assembly of magnetic nanocrystals/graphene oxide nanosheets on tumor cells enables efficient cancer therapy

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Nano Research 2020年第4期13卷 1133-1140页

作者： Mingyang Liu Yang Lu Qilin Yu Shu-Hong Yu Key Laboratory of Molecular Microbiology and Technology Ministry of EducationDepartment of MicrobiologyCollege of Life SciencesNankai UniversityTianjin 300071China division of nanomaterials and Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleCAS Center for Excellence in NanoscienceDepartment of ChemistryUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of advanced Catalytic Materials and Reaction Engineering School of Chemistry and Chemical EngineeringHefei University of TechnologyHefei 230009China

Owing to the stimulus-responsive and dynamic properties,magnetism-driven assembly of building blocks to form ordered structures is always a marvelous *** abundant magnetic assemblies have been developed in ideal physical and chemical conditions,it remains a challenge to realize magnetic assembly in complicated biological ***,we report a kind of biomacromolecule-modified magnetic nanosheets,which are mainly composed of superparamagnetic graphene oxide(Y-Fe2O3@GO),the tumor-targeting protein transferrin(TF),and the mitochondrion-targeting peptide(MitP).Such large-size nanosheets(0.5-1μm),noted as L-Fe2O3@GO-MitP-TF,can successfully in s itu assemble on the surface of tumor cells in a size-dependent and tumor cell-specific way,leading to severe inhibition of nutrient uptake for the tumor *** significantly,the nanostructures could efficiently confine the tumor cells,preventing both invasion and metastasis of tumor cells both in vitro and in ***,the 2D assemblies could remarkably disrupt the mitochondria and induce apoptosis,remarkably eradicating tumors under near-infrared(NIR)*** study sheds light on the development of new nano-systems for efficient cancer therapy and other biomedical applications.

关键词： magnetic assembly graphene oxide transferrin mitochondrion-targeting peptide metastasis cancer therapy

A new approach for accurate determination of particle sizes in microfluidic impedance cytometry

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Nanotechnology and Precision Engineering 2022年第4期5卷 8-17页

作者： N.Priyadarshi Usama Ahmed Abbasi V.Kumaran P.Chowdhury Department of Chemical Engineering Indian Institute of ScienceBangalore 560012India Pratimesh Laboratory Indian Institute of ScienceBangalore 560012India nanomaterials Research Laboratory Surface Engineering DivisionCSIR–National Aerospace LaboratoriesBangalore 560017India

In microfluidic impedance cytometry,the change in impedance is recorded as an individual cell passes through a channel between electrodes deposited on its walls,and the particle size is inferred from the amplitude of the impedance signal using ***,because the current density is nonuniform between electrodes of finite width,there could be an error in the particle size measurement because of uncertainty about the location of the particle in the channel cross ***,a correlation is developed relating the particle size to the signal amplitude and the velocity of the particle through the *** latter is inferred from the time interval between the two extrema in the impedance curve as the particle passes through a channel with cross-sectional dimensions of 50μm(width)×30μm(height)with two pairs of parallel facing *** change in impedance is predicted using 3D COMSOL finite-element simulations,and a theoretical correlation that is independent of particle size is formulated to correct the particle diameter for variations in the cross-sectional *** this correlation,the standard deviation in the experimental data is reduced by a factor of two to close to the standard deviation reported in the manufacturer specifications.

关键词： Impedance cytometry Lab on chip COMSOL simulation

On-demand synthesis of high-quality,blue-light-active ZnSe colloidal quantum wires

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National Science Review 2022年第10期9卷 137-146页

作者： Yi Li Chong Zhang Jie Tian Liang Wu Guo-Qiang Liu Hui-Hui Li Yu-Zhuo Zhang Zhen-Chao Shao Zhen He Shu-Hong Yu Department of Chemistry Institute of Biomimetic Materials and Chemistry Anhui Engineering Laboratory of Biomimetic Materials Division of Nanomaterials and Chemistry Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of China Engineering and Materials Science Experiment Center University of Science and Technology of China

Beyond the state-of-the-art Cd-containing quantum wires(QWs),heavy-metal-free semiconductor QWs,such as ZnSe,are of great interest for next-generation environmental-benign ***,simultaneous,on-demand manipulation of their radial and axial sizes—that allows strong quantum confinement in the blue-light region—has so far been *** we present a two-step catalyzed growth strategy that enables independent,high-precision and wide-range controls over the diameter and length of ZnSe *** find that a new epitaxial orientation between the cubic-phase Ag2Se solid catalyst and wurtzite ZnSe QWs kinetically favors the formation of defect-free ultrathin *** to their high uniformity,the resulting blue-light-active,phase-pure ZnSe QWs exhibit well-defined excitonic absorption with the 1Se-1Shtransition linewidth as narrow as sub-13 *** the transient absorption spectroscopy,we further show that surface electron traps in these ZnSe QWs can be eliminated by thiol passivation,which results in long-lived charge carriers and high-efficiency solar-to-hydrogen conversion.

关键词： zinc selenide colloidal synthesis quantum wires heavy-metal-free solar conversion

Tailored PEDOT:PSS hole transport layer for higher performance in perovskite solar cells: Enhancement of electrical and optical properties with improved morphology

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Journal of Energy Chemistry 2020年第5期29卷 41-50页

作者： Khan Mamun Reza Ashim Gurung Behzad Bahrami Sally Mabrouk Hytham Elbohy Rajesh Pathak Ke Chen Ashraful Haider Chowdhury Md Tawabur Rahman Steven Letourneau Hao-Cheng Yang Gopalan Saianand Jeffrey WElam Seth BDarling Qiquan Qiao Department of Electrical Engineering Center for Advanced PhotovoltaicsSouth Dakota State UniversityBrookings 57007SDUSA Physics Department Damietta UniversityNew Damietta 34517Egypt Applied Materials division Argonne National LaboratoryArgonne 60439ILUSA Center for Nanoscale Materials Argonne National LaboratoryArgonne 60439ILUSA Global Innovative Centre for advanced nanomaterials Faculty of Engineering and Built EnvironmentThe University of NewcastleCallaghan 2308New South WalesAustralia Chemical Sciences and Engineering division Argonne National LaboratoryLemont 60439ILUSA Institute for Molecular Engineering Argonne National LaboratoryLemont 60439ILUSA Institute for Molecular Engineering University of ChicagoChicago 60637ILUSA

Precise control over the charge carrier dynamics throughout the device can result in outstanding performance of perovskite solar cells(PSCs).Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)is the most actively studied hole transport material in p-i-n structured ***,charge transport in the PEDOT:PSS is limited and inefficient because of its low conductivity with the presence of the weak ionic conductor *** addition,morphology of the underlying PEDOT:PSS layer in PSCs plays a crucial role in determining the optoelectronic quality of the active perovskite absorber *** work is focused on realization of a non-wetting conductive surface of hole transport layer suitable for the growth of larger perovskite crystalline *** is accomplished by employing a facile solventengineered(ethylene glycol and methanol)approach resulting in removal of the predominant PSS in PEDOT:*** consequence of acquiring larger perovskite crystalline domains was observed in the charge carrier dynamics studies,with the achievement of higher charge carrier lifetime,lower charge transport time and lower transfer impedance in the solvent-engineered PEDOT:PSS-based *** of this solventengineered treatment for the fabrication of MAPbI3 PSCs greatly increased the device stability witnessing a power conversion efficiency of 18.18%,which corresponds to^37%improvement compared to the untreated PEDOT:PSS based devices.

关键词： Perovskite solar cells PEDOT:PSS treatment Hole transport layer Non-wetting PEDOT:PSS surface

Stabilizing photo-induced vacancy defects in MOF matrix for highperformance SERS detection

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Nano Research 2022年第6期15卷 5347-5354页

作者： Hongzhao Sun Ge Song Wenbin Gong Weibang Lu Shan Cong Zhigang Zhao School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026China Key Lab of Nanodevices and Applications Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China Key Laboratory of Multifunctional nanomaterials and Smart Systems Chinese Academy of SciencesSuzhou 215123China division of nanomaterials Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesNanchang 330200China School of Physics and Energy Xuzhou University of TechnologyXuzhou 221018China

Photo-induced vacancy defects are employed strategically to imbue semiconductors with enhanced performance characteristics for many important applications such as surface-enhanced Raman scattering(SERS)sensing,photocatalysis,and photovoltaic ***,the long-term maintenance and use of photo-induced vacancy defects remain elusive,because of their rapid self-healing upon air *** this study,we demonstrate that photo-induced oxygen vacancy(PIVO)defects can be stabilized by the photoexcitation of metal–organic framework(MOF)materials,which is crucial for SERS *** PIVO defects in MOF materials are stable for at least two weeks in the ambient atmosphere,owing to the combination of steric hindrance and electron delocalization around vacancy defects,which significantly contrasts the short lifetime(within minutes)of PIVO defects in metal-oxide *** the formation of stable PIVO defects,a prominent SERS enhancement surpassing that of pristine MOFs is achieved,accompanied with a reduced limit of detection by three orders of ***,the additional SERS enhancement rendered by PIVO defects can be stably retained and is effective for monitoring various small molecules,such as dopamine and bisphenol A.

关键词： stable photo-induced vacancy defects metal−organic framework materials steric hindrance electron delocalization Raman spectroscopy