A5080730961- Polymer crystallization and properties
- Synthesis and properties of polymers
- Liquid Crystal Research Advancements
- Polymer Nanocomposites and Properties
- Silicone and Siloxane Chemistry
- Advanced Polymer Synthesis and Characterization
- Supramolecular Self-Assembly in Materials
- Block Copolymer Self-Assembly
- biodegradable polymer synthesis and properties
- Conducting polymers and applications
- Surfactants and Colloidal Systems
- Epoxy Resin Curing Processes
- Luminescence and Fluorescent Materials
- Dendrimers and Hyperbranched Polymers
- Supramolecular Chemistry and Complexes
- Synthesis and Properties of Aromatic Compounds
- Polymer Surface Interaction Studies
- Material Dynamics and Properties
- Organic Electronics and Photovoltaics
- Rheology and Fluid Dynamics Studies
- Tribology and Wear Analysis
- Polyoxometalates: Synthesis and Applications
- Pickering emulsions and particle stabilization
- Mesoporous Materials and Catalysis
- Molecular spectroscopy and chirality
University of Akron
2016-2025
South China University of Technology
2017-2025
Chinese Academy of Sciences
1999-2025
Changchun Institute of Applied Chemistry
1999-2025
Tarim University
2024
Seoul National University
2023
Robert Bosch (Germany)
2021-2023
University of Science and Technology of China
2023
Akron Polymer Systems (United States)
2023
University of Manitoba
2022
Composite nanofiber sheets of well-aligned polyacrylonitrile nanofibers (PAN) containing multiwall carbon nanotubes (MWCNTs) were prepared by electrospinning a MWCNT-suspended solution PAN in dimethyl formamide using moving collector. Scanning electron microscopy, atomic force transmission microscopy (TEM), IR spectroscopy, Raman X-ray scattering, and the Instron test used to characterize sheets. TEM observation showed MWCNTs parallel oriented along axes nanofibers. The mechanical properties...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGlass transition and melting behavior of poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene) (PEEK)Stephen Z. D. Cheng, M. Y. Cao, Bernhard WunderlichCite this: Macromolecules 1986, 19, 7, 1868–1876Publication Date (Print):July 1, 1986Publication History Published online1 May 2002Published inissue 1 July 1986https://doi.org/10.1021/ma00161a015RIGHTS & PERMISSIONSArticle Views1642Altmetric-Citations344LEARN ABOUT THESE METRICSArticle...
Twisting of polymer lamellae manifested by e.g. appearance concentric bands in spherulites examined a polarized optical microscope remains topic research and controversy. It has been interpreted variously as resulting from phenomena that take place during growth or structural features individual lamellae, multilamellar aggregates. Phenomena are general, even generic character. They include non-linear diffusion processes leading to rhythmic crystallization, self-induced compositional...
Creating unusual nanostructures Self-assembly often occurs when dissimilar molecular fragments are forced together by covalent bonding. Surfactants or block copolymers two common examples. Huang et al. grafted four different nanoparticles, based on polyhedral oligomeric silsesquioxanes with slightly compositions, onto a single tetrahedal core (see the Perspective Yang). Depending type of nanoparticle, they assembled into range defined, ordered supramolecular lattices similar to metal alloys....
Highly oriented, large area continuous composite nanofiber sheets made from surface-oxidized multiwalled carbon nanotubes (MWNTs) and polyacrylonitrile (PAN) were successfully developed using electrospinning. The preferred orientation of MWNTs along the fiber axis was determined with transmission electron microscopy diffraction. surface morphology height profile nanofibers also investigated an atomic force microscope in tapping mode. For first time, it observed that within much higher than...
In this Perspective, we present a unique approach to the design and synthesis of giant molecules based on "nanoatoms" for engineering structures across multiple length scales controlling their macroscopic properties. Herein, refer shape-persistent molecular nanoparticles (MNPs) with precisely defined chemical surface functionalities that can serve as elemental building blocks precision by methods such sequential "click" approach. Typical include those MNPs fullerenes, polyhedral oligomeric...
Strength of structural materials and fibers is usually increased at the expense strain failure toughness. Recent experimental studies have demonstrated improvements in modulus strength electrospun polymer nanofibers with reduction their diameter. Nanofiber toughness has not been analyzed; however, from classical property trade-off, one can expect it to decrease. Here, on basis a comprehensive analysis long (5-10 mm) individual polyacrylonitrile nanofibers, we show that nanofiber also...
Frank-Kasper (F-K) and quasicrystal phases were originally identified in metal alloys only sporadically reported soft materials. These unconventional sphere-packing schemes open up possibilities to design materials with different properties. The challenge is how correlate complex built from spheres the tunable parameters of chemical composition molecular architecture. Here, we report a complete sequence various highly ordered mesophases by self-assembly specifically designed synthesized...
The engineering of structures across different length scales is central to the design novel materials with controlled macroscopic properties. Herein, we introduce a unique class self-assembling materials, which are built upon shape- and volume-persistent molecular nanoparticles other structural motifs, such as polymers, can be viewed size-amplified version corresponding small-molecule counterparts. Among them, “giant surfactants” precise have been synthesized by “clicking” compact polar...
Analyzing and understanding the structure morphology of crystalline polymers has been remains to be a major challenge. Some issues have resisted analyses for decades. The present account illustrates how individual contributions help build body knowledge that must cover length scales ranging from submolecular features correlates them with bulk properties. Emphasis is put on structures morphologies as formed spontaneously. Possible extension research area connected fields illustrated...
For a lamella-forming poly(ethylene oxide)-block-polystyrene (PEO-b-PS) diblock copolymer (M̄nPEO = 8.7K and M̄nPS 9.2K), the glass transition temperature of PS blocks is 62 °C, melting PEO crystals around 51 °C when sample crystallized below 40 °C. The thus crystallize in one-dimensionally confined lamellar space 8.8 nm, as studied recently by one-dimensional small-angle X-ray scattering (SAXS) transmission electron microscopy. In this report, crystal orientation (the c-axis crystals)...
We have investigated the self-assembly behavior of an amphiphilic diblock copolymer, polystyrene-block-poly(ethylene oxide) (PS-b-PEO), in N,N-dimethylformamide (DMF)/water and DMF/acetonitrile. In both cases water acetonitrile are selective solvents for PEO block. The degrees polymerization PS blocks were 962 227 (PS962-b-PEO227), respectively. Micelle morphologies block copolymer systems could be controlled by varying solvent concentrations. With increasing concentration DMF/water or...
A novel giant surfactant possessing a well-defined hydrophilic head and hydrophobic polymeric tail, polystyrene-(carboxylic acid-functionalized polyhedral oligomeric silsesquioxane) conjugate (PS-APOSS), has been designed synthesized via living anionic polymerization, hydrosilylation, thiol-ene "click" chemistry. PS-APOSS forms micelles in selective solvents, the micellar morphology can be tuned from vesicles to wormlike cylinders further spheres by increasing degree of ionization carboxylic...
Abstract Thermal analysis was performed on poly(butylene terephthalate), PBT, between 210 and 560 K. By combination of experimental heat capacities with computations an approximate frequency spectrum 65 group 19 skeletal vibrations, preliminary recommended ATHAS (1988) are proposed for the solid state from 0 to 600 The Tarasov parameters used computation vibrations were θ 1 = 542 K 3 80 crystalline PBT 40 amorphous PBT. glass transition temperature found efficiently quenched samples be 248...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGlass transition and melting behavior of poly(thio-1,4-phenylene)Stephen Z. D. Cheng, Zong Quan Wu, Bernhard WunderlichCite this: Macromolecules 1987, 20, 11, 2802–2810Publication Date (Print):November 1, 1987Publication History Published online1 May 2002Published inissue 1 November 1987https://doi.org/10.1021/ma00177a028Request reuse permissionsArticle Views631Altmetric-Citations189LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGlass transition and melting behavior of poly(ethylene 2,6-naphthalenedicarboxylate)Stephen Z. D. Cheng Bernhard WunderlichCite this: Macromolecules 1988, 21, 3, 789–797Publication Date (Print):March 1, 1988Publication History Published online1 May 2002Published inissue 1 March 1988https://pubs.acs.org/doi/10.1021/ma00181a040https://doi.org/10.1021/ma00181a040research-articleACS PublicationsRequest reuse permissionsArticle...
Temperature-induced reversible morphological changes of polystyrene-block-poly(ethylene oxide) micelles with degrees polymerization 962 for the PS and 227 PEO blocks (PS962-b-PEO227) in N,N-dimethylformamide (DMF)/water, which water is a selective solvent block, were observed. For system 0.2 wt % copolymer concentration 4.5 DMF/water, micelle morphology observed transmission electron microscopy changed from vesicles at room temperature to worm-like cylinders then spheres increasing...
Lamellar single crystals grown in dilute solutions can be used as templates for tethered chain analysis. Two series of diblock copolymers, poly(ethylene oxide)-block-polystyrene (PEO-b-PS) and poly(l-lactic acid)-block-polystyrene (PLLA-b-PS), were model to generate PS blocks on the single-crystal basal surfaces. Controlled tunable reduced tethering density, σ, defined by σπRg2 (where σ is density equal reciprocal covered area Rg radius gyration this its end-free state at same conditions),...
The design, synthesis, and self-assembly of a series precisely defined, nonspherical, polyhedral oligomeric silsesquioxane (POSS)-based molecular Janus particles are reported. synthesis aims to fulfill the "click" philosophy by using thiol-ene chemistry efficiently install versatile functionalities on one POSS cages. In such way, both geometrical chemical symmetries were broken create feature. These self-organize into hierarchically ordered supramolecular structures in bulk. For example,...
An approach to multicomponent coordination-driven self-assembly of the first terpyridine-based, shape-persistent, giant two-dimensional D(6h) supramacromolecular spoked wheel is reported. Mixing core T6, rim T3, and Zn(II) or Cd(II) ions in a stoichiometric ratio (1:6:12) permitted selective generation highly symmetric 94% isolated yield via geometric thermodynamic control. The products were characterized by combination traveling-wave ion mobility mass spectrometry NMR techniques together...