Lu, Ying; Sun, Yingying; Li, Lan; Men, Yongfeng
Influence of propylene-based elastomer on stress-whitening for impact copolymer
Two pure impact copolymer polypropylenes (ICP), one pure homo-polypropylene (HPP) and their compounds with different type and fraction of Vistamaxx™ propylene-based elastomer (“Vistamaxx”) were used to investigate the stress whitening activated in the impact processes via ultra-small-angle X-ray scattering technique. The whitening presented in ICP is confirmed to be caused…
Initiation of cavitation upon drawing of pre-oriented polypropylene film: In situ SAXS and WAXD studies
Xiong, Bijin; Kang, Jian; Chen, Ran; Men, Yongfeng
Initiation of cavitation upon drawing of pre-oriented polypropylene films has been investigated via in-situ small angle X-ray scattering (SAXS) and wide angle X-ray diffraction (WAXD) techniques. The macroscopic strains for the initiation of the cavitation εcav and for the initiation of crystal shear εcs have been estimated from in-situ SAXS…
Insights into gliadin supramolecular organization at digestive pH 3.0
Herrera, M. G.; Vazquez, D. S.; Sreij, R.; Drechsler, M.; Hertle, Y.; Hellweg, T.; Dodero, V. I.
Alpha-gliadin is a highly immunogenic protein from wheat, which is associated with many human diseases, like celiac disease and non-celiac gluten sensitivity. Because of that, gliadin solution is subject to intense biomedical research. However, the physicochemical nature of the employed gliadin solution at physiological pH is not understood. Herein, we…
Inter-fibrillar tie chains determined critical stress of large strain cavitation in tensile stretched isotactic polypropylene
Lu, Ying; Lyu, Dong; Xiong, Bijin; Chen, Ran; Men, Yongfeng
Isotactic polypropylene (iPP) samples with pure mesophase, pure α modification, and coexistence of both phases were used to investigate the sudden stress whitening triggered at large strain during stretching. This whitening was caused by the cavities generated in the highly oriented amorphous network. The critical stresses of such cavitation-induced whitening…
Integration of lysozyme into chitosan nanoparticles for improving antibacterial activity
Wu, Tiantian; Wu, Chunhua; Fu, Shalu; Wang, Liping; Yuan, Chunhong; Chen, Shiguo; Hu, Yaqin
Lysozyme was integrated into chitosan nanoparticles (CS-NPs) to improve the antibacterial activity. CS-NPs and chitosan-lysozyme nanoparticles (CS-Lys-NPs) were prepared according to the ionic gelation technique and then characterized by average size, zeta potential, polydispersity index (PDI), atomic force microscopy (AFM), fourier transform infrared (FT-IR), small-angle X-ray scattering (SAXS),…
Investigating solvent effects on aggregation behaviour, linear and nonlinear optical properties of silver nanoclusters
Bhavitha, K. B.; Nair, Anju K.; Perumbilavil, Sreekanth; Joseph, Saju; Kala, M. S.; Saha, Abhijit; Narayanan, R. Aravinda; Hameed, Nishar; Thomas, Sabu; Oluwafemi, Oluwatobi S.; Kalarikkal, Nandakumar
We herein report the solvent effects on the aggregation, linear and nonlinear optical properties of silver nanoclusters synthesised using three solvents namely; ethanol, acetone and isopropanol. The Ag clusters were characterized using UV–Visible (UV–vis) and photoluminescence (PL) spectroscopy, Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), high…
Isothermal crystallization kinetic modeling of poly(etherketoneketone) (PEKK) copolymer
Choupin, T.; Fayolle, B.; Régnier, G.; Paris, C.; Cinquin, J.; Brulé, B.
Isothermal melt and cold crystallizations of a poly(etherketoneketone) (PEKK) copolymer prepared from diphenyl ether (DPE), terephthalic acid (T) and isophthalic acid (I) with a T/I ratio of 60/40 have been investigated by differential scanning calorimetry, wide-angle X-ray scattering and polarized optical microscopy. For the first time, the two-stage overall crystallization…
Kinetics of Nucleation and Growth of Form II to I Polymorphic Transition in Polybutene-1 as Revealed by Stepwise Annealing
Qiao, Yongna; Wang, Qiao; Men, Yongfeng
Kinetics of II to I polymorphic transformation in isotactic polybutene-1 (PB-1) and its annealing temperature and time dependencies have been investigated by means of differential scanning calorimetry and in situ wide-angle X-ray diffraction techniques. The PB-1 samples were isothermally crystallized into metastable form II crystalline modification followed by annealing at…
Lamellar Thickness Dependence of Crystal Modification Selection in the Syndiotactic Polystyrene γ-to-α/β Phase Transition Process
Wang, Hai; Wu, Chunji; Cui, Dongmei; Men, Yongfeng
The syndiotactic polystyrene (sPS) γ-to-α/β phase transition was investigated using temperature-dependent synchrotron wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) measurement. The sPS γ form samples, which were obtained from acetone solvent induced crystallization followed by annealing at various temperatures (Ta), exhibited a regular manner on the selection of…
Lamellar structures in fluorinated phosphonium ionic liquids: the roles of fluorination and chain length
Rauber, Daniel; Zhang, Peng; Huch, Volker; Kraus, Tobias; Hempelmann, Rolf
Ionic liquids (ILs) exhibit tunable behaviour and properties that are due to their supramolecular structure. We synthesized a series of alkylated and fluorinated phosphonium dicyanamide ILs to study the relation between molecular structure and assembly with a focus on the roles of cation chain length and fluorination. Small angle X-ray…