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Flexible synthesis of high-purity plasmonic assemblies

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Nano Research 2021年第3期14卷 635-645页

作者： Laurent Lermusiaux anum Nisar Alison M.Funston ARC Centre of Excellence in Exciton Science and School of Chemistry Monash UniversityClaytonVIC3800Australia

The self-assembly of nanoparticles has attracted a vast amount of attention due to the ability of the nanostructure to control light at the sub-wavelength scale,along with consequent strong electromagnetic field ***,most approaches developed for the formation of discrete assemblies are limited to a single and homogeneous system,and incorporation of larger or asymmetrical nanoparticles into assemblies with high purity remains a key ***,a simple and versatile approach to assemble nanoparticles of different sizes,shapes,and materials into various discrete homo-or hetero-structures using only two complementary deoxyribonucleic acid(DNA)strands is ***,surface functionalisation using DNA and alkyl-polyethylene glycol(PEG)enables transformation of as-synthesised nanoparticles into readily usable plasmonic building blocks for *** of the DNA coverage enables the production of different assembly types,such as homo-and hetero-dimers,trimers and tetramers and core-satellite structures,which are produced in high purity using electrophoresis *** approach is extended from purely plasmonic structures to incorporate(luminescent)semiconductor nanoparticles for formation of hybrid *** deposited assemblies form a high yield of specific geometrical arrangements,attributed to the van der Waals attraction between *** method will enable the development of new complex colloidal nanoassemblies for biological and optical applications.

关键词： deoxyribonucleic acid(DNA)self-assembly electrophoretic purification nanoparticle assemblies colloidal stability

Theoretical Study of Halogen Effect in Isomerization of 2-Halo-[9]-annulen Anion at the DFT Level

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Chinese Journal of Structural Chemistry 2011年第6期30卷 906-912页

作者： AHMADREZA Bekhradnia sattar Arshadi Pharmaceutical Sciences Research Center Department of Medicinal ChemistryMazandaran University of Medical Sciences Department of Chemistry Payame Noor UniversityBehshahr Unit

Cis-trans isomerization of [9]-annulenanion（1） and its 2-fluoro-,2-chloro-and 2-bromo-derivatives（2,3 and 4,respectively） were investigated at the HF/6-31G＊ and B3LYP/6-311＋＋G＊＊ levels of ***,cis,cis,cis structures appear more stable than their corresponding cis,cis,cis,*** relative height of energy barriers for cis-trans isomerization is：2cis 〉1cis 〉3cis〉 *** trend for the reverse trans-cis isomerization follows the electronegativity of the substituent at C-2（2trans 3trans 4trans 1trans）.

关键词： isomerization halogen effects -annulen anion DFT

Mixed Matrix Membranes of Polysulfone/Polyimide Reinforced with Modified Zeolite Based Filler: Preparation, Properties and Application

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Chinese Journal of Polymer Science 2018年第1期36卷 65-77页

作者： Sedra Tul Muntha Muhammad Siddiq Ayesha Kausar anum Khan Department of Chemistry Quaid i Azam University Department of Microbiology Quaid i Azam University

In this work, polysulfone/polyimide（PSf/PI） mixed matrix membranes were fabricated by reinforcement of modified zeolite（MZ） particles through solution casting method for investigation of antibacterial activity against two gram negative bacteria（Salmonella typhi, Klebsella pneumonia） and two gram positive bacteria（Staphylococcus aureus, Bacillus subtilis）. The modified zeolite particles were incorporated to PSf and PI matrix and the influence of these particles on thermal, mechanical and structural properties was evaluated. The morphological evolution was investigated through scanning electron microscopy（SEM） and transmission electron microscopy（TEM） analysis, which revealed good compatibility between organic polymer matrix and inorganic filler. Mechanical stability was investigated by tensile testing while thermal analysis was evaluated by thermogravimetric analysis（TGA） and differential scanning calorimetry（DSC）. This revealed improvement in thermal properties with increasing filler concentration from 1 wt% to 10 wt%. Structural analysis was successfully done using X-ray diffraction analysis（XRD） and Fourier transform infrared（FTIR） spectroscopy. Solvent content of fabricated mixed matrix membranes was observed to decrease while moving from more hydrophilic to less hydrophilic solvent. However, addition of filler content enhanced the porosity of fabricated membranes. The synthesized mixed matrix membranes exhibited good antibacterial activity and the highest activity was shown by PSf/PI/MZ mixed matrix membrane. Therefore, the combination effect of PSf, PI and MZ sufficiently enhanced the antibacterial activity of mixed matrix membranes.

关键词： Modified zeolite Polysulfone/polyimide blend membrane Mixed matrix membrane Thermal analysis Antibacterial activity

Topomerization of 2-Halo-[9] Annulen Anion at the DFT Level

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Chinese Journal of Structural Chemistry 2011年第10期30卷 1509-1516页

作者： sattar Arshadi AHMADREZA Bekhradnia Department of Chemistry Payame Noor University Pharmaceutical Sciences Research Center Department of Medicinal ChemistryMazandaran University of Medical Sciences

Topomerization of [9] annulen anion （1） and its 2-fluoro-, 2-chloro- and 2- bromo-defivatives （2, 3 and 4, respectively） are studied at the HF/6-31G＊ and B3LYP/6-31 1＋＋G＊＊ levels of theory. The relative ease of topomerization is dependent on the charge distribution and planarity of the ground state and the transition state of 9-membered rings as well as the size and electronegativity of halogen substituent. Consequently, the endo-2-halo-[9] annulen anion topomers become unstable and easily convert to related exo-topomers. Hence, according to the DFT calcu- lations, the order of topomerization energy barrier for endo = exo topomerization is lendo 〉 2endo 〉 3endo.

关键词： topomerization substiuent effects 2-halo- annulen anion DFT

Thermal, Mechanical and Electrical Studies of Novel Shape Memory Polyurethane/Polyaniline Blends

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Chinese Journal of Polymer Science 2015年第9期33卷 1313-1324页

作者： Rabia sattar Ayesha Kausar Muhammad Siddiq Department of Chemistry Quaid-i-Azam University Nanosciences and Catalysis Division National Centre for Physics Quaid-i-Azam University Campus

Shape memory polymer （SMP） blends based on polyurethane （PU） and polyaniline （PANI） were prepared via chemical in situ polymerization process. The thermal, mechanical, electrical and shape memory properties were investigated. The structural characterization and morphology of the polymer blends were inspected by Fourier transform infrared （FTIR） and scanning electron microscopy （SEM）, respectively. The 1 wt% of PANI loading enhanced the thermal stability of the system up to 339 ~C. According to differential scanning calorimetry （DSC）, the glass transition temperature （Tg） and melting temperature （Tm） of PU/PANI blends increased with the polyaniline loading （0.1 wt%-l wt%）. Improved mechanical properties such as tensile strength and Young＇s modulus of PU matrix were also observed with PANI. Moreover, the electrical conductivity of PU/PANI blends was also found to be a function of PANI loading. Remarkable recoverability of thermally triggered shape memory （SM） behavior to the extent of 96% was achieved for 1 wt% PANI blend.

关键词： Shape memory Polyurethane Polyaniline Blends Conductivity.

One-pot synthesis of 1,3-thiazolidin-4-one using Bi(SCH_2COOH)_3 as catalyst

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Chinese Chemical Letters 2013年第5期24卷 389-391页

作者： Naser Foroughifar sattar Ebrahimi Faculty of Chemistry North Tehran BranchIslamic Azad University Department of Chemistry Malayer Branch Islamic Azad University

A catalytic multi-component reaction involving aromatic amine,aromatic aldehydes,mercapto acid as substrates and Bi（SCH_2COOH）_3 as catalyst under solvent free conditions,afforded thiazolidin-4-one in good *** efficiency of the catalyst was proved with a variety of substrates,ranging from electrondeficient to electron-rich aldehydes.

关键词： Thiazolidin-4-one Mercapto acid Multicomponent Thioglycolic acid

Microstructural evolution and intermetallic formation in Al-8wt% Si-0.8wt% Fe alloy due to grain refiner and modifier additions

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International Journal of Minerals,Metallurgy and Materials 2012年第8期19卷 739-746页

作者： Amir Hassani Khalil Ranjbar sattar Sami Faculty of Materials Science and Engineering University of Semnan Semnan Iran Materials Department Faculty of Engineering Shahid Chamran University Ahwaz Iran

An alloy of A1-8wt% Si-0.8wt% Fe was cast in a metallic die, and its microstrucmral changes due to Ti-B refiner and Sr modifier additions were studied. Apart from usual refinement and modification of the microstructure, some mutual influences of the additives took place, and no mutual poisoning effects by these additives, in combined form, were observed. It was noticed that the dimensions of the iron-rich intermetallics were influenced by the additives causing them to become larger. The needle-shaped intermetallics that were obtained from refiner addition became thicker and longer when adding the modifier. It was also found that a-Al and eutectic silicon phases preferentially nucleate on different types of intermetallic compounds. The more iron content of the intermetallic compounds and the more changes in their dimensions occurred. Formation of the shrinkage porosities was also observed.

关键词： aluminum alloys metal casting grain refinement modification metallographic microstructure intermetallics

Exogenously applied glycinebetaine induced alteration in some key physio-biochemical attributes and plant anatomical features in water stressed oat(Avena sativa L.) plants

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Journal of Arid Land 2019年第2期11卷 292-305页

作者： anum SHEHZADI Nudrat A AKRAM Ayaz ALI Muhammad ASHRAF Department of Botany Government College University Pakistan Science Foundation Department of Botany King Saud University

Although exogenous application of glycinebetaine(GB) is widely reported to regulate a myriad of physio-biochemical attributes in plants under stressful environments including drought stress, there is little information available in the literature on how and up to what extent GB can induce changes in anatomical features in water starved plants. Thus, the present research work was conducted to assess the GB-induced changes in growth, physio-biochemical, and anatomical characteristics in two cultivars(CK-1 and F-411) of oat(Avena sativa L.) under limited water supply. After exposure to water stress, a considerable reduction was observed in plant growth in terms of lengths and weights of shoot and roots,leaf mesophyll thickness, leaf midrib thickness, root cortex thickness, root diameter, stem diameter, stem phloem area, and stem vascular bundle area in both oat cultivars. However, water stress resulted in a significant increase in leaf total phenolics, hydrogen peroxide(H_2 O_2), ascorbic acid(AsA), GB contents,activities of enzymes(CAT, SOD and POD), total soluble proteins, leaf epidermis(abaxial and adaxial)thickness, bulliform cell area, sclerenchyma thickness, root endodermis and epidermis thickness, root metaxylem area, stem metaxylem area and stem sclerenchyma thickness in both oat ***-applied 100 mM GB suppressed H_2 O_2 contents, while improved growth attributes, free proline and GB contents, activity of SOD enzyme, leaf abaxial epidermis thickness, leaf bulliform cell area, leaf midrib thickness, leaf sclerenchyma thickness, root cortex thickness, root endodermis, epidermis thickness,root stele diameter, stem diameter, stem epidermis thickness, stem metaxylem area, and stem phloem and vascular bundle area in both oat cultivars. For both oat cultivars, CK-1 was superior to F-411 in leaf abaxial epidermis thickness, leaf mesophyll, leaf sclerenchyma, root metaxylem area, stem diameter, stem epidermis, sclerenchyma thickness, stem metaxylem area, and

关键词： drought tolerance anatomical features oat glycinebetaine antioxidants

Advantages of using gold hollow nanoshells in cancer photothermal therapy

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Chinese Physics B 2016年第8期25卷 322-330页

作者： sattar Abbasi Mojtaba Servatkhah Mohammad Mehdi Keshtkar Department of Physics Marvdasht Branch Islamic Azad University Department of Physics Payame Noor University

Lots of studies have been conducted on the optical properties of gold nanoparticles in the first region of near infrared（650 nm–950 nm）, however new findings show that the second region of near-infrared（1000 nm–1350 nm） penetrates to the deeper tissues of the human body. Therefore, using the above-mentioned region in photo-thermal therapy（PTT） of cancer will be more appropriate. In this paper, absorption efficiency is calculated for gold spherical and rod-shaped nanoshells by the finite element method（FEM）. The results show that the surface plasmon frequency of these nanostructures is highly dependent on the dimension and thickness of shell and it can be adjusted to the second region of near-infrared. Thus, due to their optical tunability and their high absorption efficiency the hollow nanoshells are the most appropriate options for eradicating cancer tissues.

关键词： surface plasmon absorption efficiency near-infrared nanotubes