bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zirconium tungstate/polymer nanocomposites: Challenges and opportunities
Authors: Lind Cora , Coleman Maria R. , Kozy Leah C. , Sharma Gayathri R. 
Published: August 2010

AbstractNegative thermal expansion (NTE) oxides are interesting materials for use in controlled thermal expansion composites. Cubic ZrW2O8 is one of the most promising candidates due to its strong, isotropic NTE behaviour over a large temperature range. It is easily accessible from a hydrated precursor, ZrW2O7(OH)2 · 2H2O, which enables control of particle size and morphology during the topotactic conversion to the NTE phase. The preparation of high quality composites poses a number of challenges like compatibility of NTE material and composite matrix, stability of the NTE phase and particle morphology and size, which affect mixing and homogeneity. For ZrW2O8/polymer composites, surface modification is necessary to enhance interactions between the polymer matrix and the filler particles. In addition, small particle sizes are crucial to avoid settling of filler particles during polymer processing. This review presents results on the optimization of routes to nano‐ZrW2O8, particle modification to achieve compatibility with polymers, preparation of NTE/polyimide composites and potential problems that can interfere with composite formation.
Thermal strain recovery of anelastic monodomain liquid crystalline networks: Mechanically induced strains ratios
Authors: Ren Wanting , Kline Whitney M. , McMullan Philip J. , Griffin Anselm C. 
Published: August 2010

AbstractA series of smectic liquid crystalline network polymers was subjected to a large uniaxial stress at temperatures far below the clearing temperature. Their dimensional recovery is anelastic showing substantial retained strain. This process produced a temporally stable monodomain state. Upon heating this monodomain from room temperature, recovery of the original film dimensions occurs. The strain recovery (length) curves show a pronounced curvature as the temperature approaches the smectic–isotropic temperature. It is proposed that nanosegregation of netpoints in the smectic structure is responsible for the anelasticity and that the temperature dependence of the shape recovery is consistent with a balance between enthalpic and entropic forces with temperature. An interesting mechanically induced strains ratio (MISR) was observed on heating these pre‐stressed films. Loss of the monodomain structure near the isotropization temperature is postulated to rationalize the shape of the MISR curves.magnified image
Group IV Nanoparticles: Synthesis, Properties, and Biological Applications
Authors: Fan Jiyang , Chu Paul K. 
Published: August 2010

AbstractIn this review, the emerging roles of group IV nanoparticles including silicon, diamond, silicon carbide, and germanium are summarized and discussed from the perspective of biologists, engineers, and medical practitioners. The synthesis, properties, and biological applications of these new nanomaterials have attracted great interest in the past few years. They have gradually evolved into promising biomaterials due to their innate biocompatibility; toxic ions are not released when they are used in vitro or in vivo, and their wide fluorescence spectral regions span the near‐infrared, visible, and near‐ultraviolet ranges. Additionally, they generally have good resistance against photobleaching and have lifetimes on the order of nanoseconds to microseconds, which are suitable for bioimaging. Some of the materials possess unique mechanical, chemical, or physical properties, such as ultrachemical and thermal stability, high hardness, high photostability, and no blinking. Recent data have revealed the superiority of these nanoparticles in biological imaging and drug delivery.
Capture and Culturing of Living Cells on Microstructured DNA Substrates
Authors: Reisewitz Stephanie , Schroeder Hendrik , Tort Nuria , Edwards Katie A. , Baeumner Antje J. , Niemeyer Christof M. 
Published: August 2010

AbstractA modular system for the DNA‐directed immobilization of antibodies was applied to capture living cells on microstructured DNA surfaces. It is demonstrated in two different set‐ups, static incubation and hydrodynamic flow, that this approach is well suited for specific capture and selection of cells from culture medium. The adhered cells show intact morphology and they can be cultivated to grow to dense monolayers, restricted to the lateral dimensions of DNA spots on the surface. Owing to the modularity of surface biofunctionalization, the system can readily be configured to serve as a matrix for adhesion and growth of different cells, as demonstrated by specific binding of human embryonic kidney cells (HEK293) and Hodgkin lymphoma L540cy cells onto patches bearing appropriate recognition moieties inside a microfluidic channel. We therefore anticipate that the systems described here should be useful for fundamental research in cell biology or applications in biomedical diagnostics, drug screening, and nanobiotechnology.
Review of literature and resin manufacturer molecular weight‐viscosity relationships for PVC
Authors: Patterson M. C. , Dunkelberger D. L. 
Published: August 2010

AbstractAccurate molecular weight characterization of PVC is necessary before attempting to modify the properties of the polymer using additives and/or process the compound in some fashion. Commercial PVC resins are characterized by many different dilute solution viscosity methods. Manufacturers characterize their resins using K values, specific viscosity, relative viscosity, viscosity numbers, and inherent viscosity. Each of these methods can vary according to solvent used, testing temperature, and resin concentration. This paper reviews the technical literature and information published by the major PVC resin producers regarding molecular weight characterization. The information in this review should be useful for scientists and engineers in the PVC industry to translate between and among the various test methods for molecular weight characterizations.
Mechanistic aspects of organotin stabilization of PVC
Authors: Burley J. W. 
Published: August 2010

AbstractPrompted by commercial significance and academic interest, extensive model compound and in‐situ studies of PVC degradation/stabilization appear in the literature. This paper presents the results of some in‐situ studies of the chemical reaction pathways undergone by organotin thioglycollate esters during PVC stabilization. Infrared spectroscopy indicates that in the case of diocyltin bis(isooctylthioglycollate), not only is the mercaptoester/chloride generated, but also the corresponding thioglycollate (Oct2 Sn TG). The extent to which this species is observed is dictated by the processing technique. An attempt is made to correlate the chemical reaction pathway of the organotin compounds with the changes (unsaturation) within the polymer. The possible relevance of these observations to the phenomenon of mono/di synergism is also discussed. While these studies extend our knowledge of the organotin stabilization of PVC, they also show that our understanding is far from complete.
Designing with glass reinforced vinyl composites. I: The effect of time and temperature on modulus values
Authors: Woods M. E. , Rodriguez E. L. , Millward D. R. 
Published: August 2010

AbstractIn designing for stiffness of polymer products, one of the most common questions asked by design engineers is: “What are the effects of time and temperature on the modulus values listed on the product data sheet?” This paper outlines our approach to provide answers for glass reinforced Fiberloc® vinyl composites. Static and dynamic mechanical techniques and time‐temperature superposition principles were used to predict modulus as a function of both temperature and time under load. The predictions are being verified by long‐term creep tests at several temperatures.
Hydrodynamic analysis of calenderable PVC and ABS compounds
Authors: Dotson Seldon L. , Simmons Larry B. 
Published: August 2010

AbstractCalendering of rigid and semirigid PVC (and ABS) compounds require an understanding of compound rheology and critical processing parameters. Compound rheology is modified with processing aids and lubricants. The choice of processing aid can be critical to achieving the desired rheology needed for calendering. This paper will focus on defining calendering rheology parameters as a function of a super high molecular weight MMA/SAN copolymer processing aid. These rheology parameters will be defined in terms of mill roll gap pressure, adhesive force (compound roll release) melt temperature, and shear rate. The ability to measure these parameters via a computerized two roll mill and relate this data to the actual calendering line will also be discussed.
Expanding PVC as a building material
Authors: Patterson John , Szamborski Gene 
Published: August 2010

AbstractRigid vinyl foam can currently be found in applications such as profile, sheet, and foam core pipe, but it is still a curiosity in house siding and other wood replacement applications. This paper looks at the potential for vinyl foam as an alternative for wood, comparing its end‐use capabilities. In addition, the various types of extrusion processes, and formulations, are compared, and the effect of certain types of formulation ingredients on density, surface quality, and other physical properties are described.
Flow properties of long fiber reinforced PP sheets
Authors: Hamada Hiroyuki , Yamaguchi Susumu 
Published: August 2010

AbstractLong glass fiber reinforced PP sheets, called stampable sheets, are attractive materials because of their light weight, high strength, high moldability, recyclability, and so on. Therefore, stampable sheets have been used in comparatively large products such as bumper beams or seat shells in the car industry. In order to design molds and select adequate molding conditions, flow patterns of stampable sheet must be characterized. In this paper, we carried out the finite element method of the flow of stampable sheet, using the lamination theory. One‐ply sheet can be regarded as two PP resin layers and one reinforced layer. Large deformation analysis was performed with heat condition analysis, and the material was modeled as an elastic‐perfect plastic material. In‐plane and out‐plane flow patterns were analyzed. In the former, the material flow occurred in the plane, as in the fabrication of plane sheet, and in the latter, the flow pattern was as in the case of ribs or boss parts. Numerical results suggested that in‐plane flow was characterized by slippage flow, and out‐plane flow was characterized by squeezing flow.
Electrically active nanomaterials as improved neural tissue regeneration scaffolds
Authors: Seil Justin T. , Webster Thomas J. 
Published: August 2010

AbstractNumerous biomaterials have provided promising results toward improving the function of injured nervous system tissue. However, significant hurdles, such as delayed or incomplete tissue regeneration, remain toward full functional recovery of nervous system tissue. Because of this continual need for better nervous system biomaterials, more recent approaches to design the next generation of tissue engineering scaffolds for the nervous system have incorporated nanotechnology, or more specifically, nanoscale surface feature dimensions which mimic natural neural tissue. Compared to conventional materials with micron‐scale surface dimensions, nanomaterials have exhibited an ability to enhance desirable neural cell activity while minimizing unwanted cell activity, such as reactive astrocyte activity in the central nervous system. The complexity of neural tissue injury and the presence of inhibitory cues as well as the absence of stimulatory cues may require multifaceted treatment approaches with customized biomaterials that nanotechnology can provide. Combinations of stimulatory cues may be used to incorporate nanoscale topographical and chemical or electrical cues in the same scaffold to provide an environment for tissue regeneration that is superior to inert scaffolds. Ongoing research in the field of electrically active nanomaterials includes the fabrication of composite materials with nanoscale, piezoelectric zinc oxide particles embedded into a polymer matrix. Zinc oxide, when mechanically deformed through ultrasound, for example, can theoretically provide an electrical stimulus, a known stimulatory cue for neural tissue regeneration. The combination of nanoscale surface dimensions and electrical activity may provide an enhanced neural tissue regeneration environment; such multifaceted nanotechnology approaches deserve further attention in the neural tissue regeneration field. WIREs Nanomed Nanobiotechnol 2010 2 635–647This article is categorized under:

Implantable Materials and Surgical Technologies > Nanomaterials and Implants
Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease
Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement
Novel DNA materials and their applications
Authors: Yang Dayong , Campolongo Michael J. , Nhi Tran Thua Nguyen , Ruiz Roanna C. H. , Kahn Jason S. , Luo Dan 
Published: August 2010

AbstractThe last two decades have witnessed the exponential development of DNA as a generic material instead of just a genetic material. The biological function, nanoscale geometry, biocompatibility, biodegradability, and molecular recognition capacity of DNA make it a promising candidate for the construction of novel functional nanomaterials. As a result, DNA has been recognized as one of the most appealing and versatile nanomaterial building blocks. Scientists have used DNA in this way to construct various amazing nanostructures, such as ordered lattices, origami, supramolecular assemblies, and even three‐dimensional objects. In addition, DNA has been utilized as a guide and template to direct the assembly of other nanomaterials including nanowires, free‐standing membranes, and crystals. Furthermore, DNA can also be used as structural components to construct bulk materials such as DNA hydrogels, demonstrating its ability to behave as a unique polymer. Overall, these novel DNA materials have found applications in various areas in the biomedical field in general, and nanomedicine in particular. In this review, we summarize the development of DNA assemblies, describe the innovative progress of multifunctional and bulk DNA materials, and highlight some real‐world nanomedical applications of these DNA materials. We also show our insights throughout this article for the future direction of DNA materials. WIREs Nanomed Nanobiotechnol 2010 2 648–669This article is categorized under:

Diagnostic Tools > Biosensing
Nanotechnology Approaches to Biology > Cells at the Nanoscale
Implantable Materials and Surgical Technologies > Nanomaterials and Implants
Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Synthesis Characterization, X‐ray Structures, and Solution Studies of Dinuclear Zinc(II) Complexes of Acyclic Schiff Base Ligands
Authors: Hosseini‐Yazdi Seyed A. , Khandar Ali A. , Tabatabai Mir Kh. , Noohinejad Leila 
Published: August 2010

AbstractDizinc(II) complexes of two acyclic Schiff‐base ligands L1– and L2– were synthesized by Schiff base condensation of 2‐[3‐(2‐formylphenoxy)‐2‐hydroxypropoxy]benzaldehyde (PL) with 1,2‐diaminopropane and 1,2‐diaminoethane, respectively, in the presence of zinc(II) salts. The isolation of a selection of 2:1 (metal:ligand) complexes of zinc(II) was carried out and conductance measurements, IR, UV/Vis absorption, and fluorescence emission spectroscopy, as well as X‐ray diffraction were employed to probe the nature of the respective complexes in both solid and solution states. The molecular structure of [Zn2L1(NO3)3] (1) complex consists of two six‐coordinate atoms, which are bridged by the deprotonated hydroxy group and one 1,3‐bridging nitrate anion. The structure of [Zn2L2(NO3)(H2O)2](NO3)2·CH3OH (3) consists of a dizinc cation and two nitrate anions as counterions. In compound 3, each zinc atom is bound to water instead of a terminal nitrate anion in a distorted octahedral arrangement. The intermetallic separation distance of Zn···Zn in 3 (3.376 Å) is slightly smaller than 1 (3.403 Å) and is similar to that found in zinc phosphotriesterase (3.5 Å). The π–π interactions between the benzene rings of adjacent molecules in 3 are stronger than in 1.
Three Octacyanometallate‐Based LnIII–MV (Ln = La, Ce; M = Mo, W) Bimetallic Assemblies with a One‐Dimensional Rope‐Ladder Chain Structure
Authors: Qian Su‐Yan , Zhou Hu , Zhang Ying , Yuan Ai‐Hua 
Published: August 2010

AbstractThree octacyanometallate‐based hetero‐bimetallic complexes, [Ln(H2O)4(CH3CN)2][M(CN)8]·CH3CN [Ln = La, M = Mo(1), W(2); Ln = Ce, M = W(3)], were synthesized and characterized structurally. Single‐crystal X‐ray analysis reveals that 1–3 are isomorphous and consist of infinite one‐dimensional (1D) 3,3 rope‐ladder chains, in which the 12‐membered puckered square Ln2M2(CN)4 is the basic building unit. The 1D chains are further linked through interchain hydrogen bonds, resulting in a three‐dimensional (3D) supramolecular network.
A Series of Transition Metal Coordination Polymers Bearing 1,4‐Phenylenediacetate
Authors: Chen Zilu , Zhao Qin , Xiong Wei , Zhang Zhong , Liang Fupei 
Published: August 2010

AbstractThe reactions of transition metal salts or hydroxide with 1,4‐phenylenediacetic acid (H2PDA) in the presence of ancillary ligands 4,4′‐bipyridine (4,4′‐bpy) or imidazole (Im) produced five coordination polymers with the empirical formula [M(PDA)(4,4′‐bpy)(H2O)2]n [M = Mn (1), Ni (2)], [Cu(PDA)(4,4′‐bpy)]n·2nH2O (3), [Ni(PDA)(Im)2(H2O)2]n·nH2O (4), and [Cu(PDA)(Im)2]n·2nH2O (5). Their structures were determined by single‐crystal X‐ray diffraction analyses. The isomorphous 1 and 2 present a two‐dimensional sheet constructed by two kinds of one‐dimensional chains of –NiII–PDA2––NiII– and –NiII–4,4′‐bpy–NiII–. Compound 3 features dinuclear subunits, which are further connected by two PDA2– ligands and two 4,4′‐bpy ligands along (001) and (011) directions, respectively, to build a two‐dimensional sheet with the topology (42.67.8)(42.6) different from those of 1 and 2. Both 4 and 5 show one‐dimensional chain structure. The difference of compound 4 and 5 is that the two carboxylato groups of PDA2– in 4 adopt monodentate coordination modes, whereas the two carboxylato groups of PDA2– in 5 chelate to the metal ions. Magnetic susceptibility data of 1 were measured. Magnetically, 1 presents a one‐dimensional chain with a weak antiferromagnetic interaction (J =–0.064 cm–1) between the intrachain MnII atoms mediated by 4,4′‐bpy.
Using Taguchi Robust Design Method to Develop an Optimized Synthesis Procedure for Nanocrystals of ZSM‐5 Zeolite
Authors: Abrishamkar Maryam , Azizi Seyed Naser , Kazemian Hossein 
Published: August 2010

AbstractThe effects of TPAOH/SiO2, H2O/SiO2, SiO2/Na2O and SiO2/Al2O3 ratios in the initial synthetic mixture on the crystallization of nanoparticles of ZSM‐5 zeolite under atmospheric pressure were studied. A Taguchi orthogonal experimental design with three levels of the above‐mentioned parameters was used to optimize the experiment parameters by the analysis of variances (ANOVA). Applying the Taguchi method significantly reduced the time and cost for optimization. The obtained products were characterized by scanning electron microscopy, X‐ray diffraction and FT‐IR spectroscopy. As a result of the Taguchi analysis TPAOH/SiO2 followed by SiO2/Al2O3 was the most influencing parameters for the synthesis of nanosized ZSM‐5 crystals.
Syntheses, Crystal Structures, and Physico‐Chemical Studies of Sodium and Potassium Alcoholates Bearing Thienyl Substituents and their Derived Luminescent Samarium(III) Alkoxides
Authors: Veith Michael , Belot Céline , Huch Volker , Guyard Laurent , Knorr Michael , Khatyr Abderrahim , Wickleder Claudia 
Published: August 2010

AbstractThe synthesis, structural characterisation, electrochemistry, and luminescence properties of a series of alkali metal alcoholates and samarium(III) alkoxides with thiophene‐based OR substituents are presented. The alkali metal alcoholates 7–15 were obtained by deprotonation of the carbinol with NaH or KH. Their molecular structures consist of tetranuclear alkali metal alcoholates with a distorted cubane‐like M4O4 core (X‐ray structure analyses). Each alkali metal is surrounded by three carbinolate ligands and (depending on the derivative) by additional tetrahydrofuran molecules. The mononuclear samarium alkoxides {Sm[OC(C4H3S)3]3(thf)3}·thf (16) and {Sm[OC(C16H13S)]3(thf)3}·thf (17) were synthesised by the salt metathesis reactions between {[KOC(C4H3S)3]4(thf)2}·thf (7), [NaOC(C4H3S)3]4(thf)2 (8) or {[KOC(C16H13S)]4(thf)3}·1/2thf (11), respectively, and SmCl3 in thf solution. The molecular structures of these air‐sensitive base adducts have been determined by single crystal X‐ray crystallography and reveal an approximately octahedral coordination sphere around the samarium metal atoms with three methoxido ligands and three facially arranged tetrahydrofuran molecules. The electrochemical properties are essentially dominated by the oxidation of the thienyl units. The emission spectra of the carbinols and their derived potassium and sodium compounds display broad bands attributed to the π* → π transitions of the aromatic ligands. Luminescence studies performed on complexes 16 and 17 reveal the typical f–f transitions of the SmIII ion. The photophysical data suggest that an energy transfer from the ligand to the metal atom operates.
Einfluss von H‐Brückenbindungen auf die Jahn–Teller‐Verzerrung in den Kettenstrukturen von 2,2′‐bipyMn(H2PO4)F2·H2O und 2,2′‐bipyMn(H2PO4)2F
Authors: Stief Ronald , Massa Werner 
Published: August 2010

AbstractIn the system 2,2′‐bipyridine/MnIII/HF/H3PO4/H2O two compounds with chain structures could be prepared and characterised by X‐ray structure analyses. 2,2′‐bipyMn(H2PO4)F2·H2O (1): monoclinic, twinned, space group P21/c, Z = 4, a = 6.7883(4), b = 10.9147(5), c = 17.8102(8) Å, β = 100.142(4)°, R = 0.0328. 2,2′‐bipyMn(H2PO4)2F (2): triclinic, space group P$\bar{1}$, Z = 2, a = 6.675(1), b = 10.715(1), c = 11.013(1) Å, α = 107.595(9)°, β = 90.994(9)°, γ = 95.784(8)°, R = 0.0252. Both compounds show chain structures with trans‐bridging dihydrogenphosphate ligands and bipy and two fluorine ligands for (1), or bipy, fluorine and an additional dihydrogenphosphate, respectively, for (2) in equatorial positions. Due to the pseudo‐Jahn–Teller effect, MnIII shows elongated octahedral coordination with ferrodistortive ordering along the chain direction. The distortion is remarkably higher in (1) than in (2). This is discussed in context with additional hydrogen bonds along the chain in (2).
The Platinum(II) Salt Pt(H2O)4(SbF6)2
Authors: Seppelt Konrad 
Published: August 2010

AbstractThe platinum(II) salt Pt(H2O)4(SbF6)2 is a stable compound. In the solid state the compound consists of isolated Pt(H2O)42+ cations and SbF6– anions. Space group P$\rm P\bar1$, Z = 1, lattice dimensions at 133 K: a = 503.7(2), b = 783.4(2), c = 854.1(2) pm, α = 69.03(2), β = 83.36(2), γ = 75.88(2).