Co-reporter:Xiao Liu;Qian-shi Wei;Li-guo Chai
Chinese Journal of Polymer Science 2017 Volume 35( Issue 1) pp:78-86
Publication Date(Web):2017 January
DOI:10.1007/s10118-017-1872-2
The influence of crystallization temperature (Tc) on the number of spiral growths on poly(butylene succinate) (PBS) single crystals, obtained by self-seeding method, was systematically studied. The studies show that the statistical average number of spiral growths formed on the PBS single crystals decays exponentially with respect to the Tc. Inspired by BCF (Bruton, Cabrera and Frank) theory and L-H (Lauritzen and Hoffman) theory, a thermodynamic model has been proposed, in which the origin of spiral growth was treated as a nucleation process. The model suggests that the nucleation rate of spiral growth depends on the inverse square of super-cooling degree, which predicted the density of spiral growth formed on lamellae, and was consistent with the experiments very well.
Co-reporter:Xuan Zhou;Xinshuo Zhang;Lin Li
RSC Advances (2011-Present) 2017 vol. 7(Issue 20) pp:12247-12254
Publication Date(Web):2017/02/16
DOI:10.1039/C6RA27417J
6-Deoxy-6-(2-aminoethyl) amino chitosan (CS-AEA) and aminoethyl modified CS-AEA (CS-AEA-AEM) were synthesized and characterized using FTIR, NMR and elemental analysis. The results showed that the expected CS derivatives were obtained, and the amine group content increased successively in CS, CS-AEA and CS-AEA-AEM. The red blood cell (RBC) agglutination behaviors in solutions of CS and its derivatives were studied using optical microscopy (OM) and ultraviolet-visible (UV-Vis) spectrophotometry. The results demonstrated that the agglutination of RBCs became more evident upon decreasing the pH value and increasing the concentration. Although CS-AEA-AEM had the highest content of amine groups, CS-AEA exhibited the best agglutination performance under the pH and concentration range studied. Potentiometric titration and ionization degree calculations showed that the agglutination behavior of RBCs was determined by the number of protonated amines in CS or its derivatives. Hemocompatibility tests showed that the hemolysis of CS derivatives increased after modification, and the CS derivatives could be classified as a slightly hemolytic material. We have sucessfully developed a CS derivative (CS-AEA) with very good RBC agglutination performance under neutral conditions.
Co-reporter:Jing Wang, Zhiyu Hu, Xiunan Yin, Yunchao Li, Hong Huo, Jianjun Zhou, Lin Li
Electrochimica Acta 2015 Volume 159() pp:61-65
Publication Date(Web):20 March 2015
DOI:10.1016/j.electacta.2015.01.208
•PEK-C (Tg: ∼230 °C) was used as binder to prepare ceramic coated composite PP separator.•The composite PP separator was stable and showed low thermal shrinkage in the electrolyte solvent.•The composite PP separator was helpful for high current density discharge.•The composite PP separator improved the safety performance of the coin cells.One way to obtain the lithium ion power battery with better safety performance was to increase the thermal shrinkage resistance of the separator at higher temperature. Phenolphthalein polyetherketone (PEK-C) is a polymer that can withstand high temperature to about 230 °C. Here, we developed a new Al2O3 coated composite polypropylene (PP) separator with PEK-C as binder. The coating layer was formed on the surface of the PP separator and both ceramic particles and binder did not infiltrated into the separator along the thickness direction. The composite separator with 4 μm coating layer provided balanced permeability and thermal shrinkage properties. The composite separator was stable at the electrochemical window for lithium ion battery. The coin cells with composite separator showed better charge/discharge performance than that of the cells with the PP separator. It seemed that the composite separator was helpful for high current density discharge. Also, the battery safety performance test had verified that the Al2O3 coated composite separator with PEK-C as binder had truly improved the safety performance of the coin cells. So, the newly developed Al2O3 coated composite PP separator was a promising safety product for lithium ion power batteries with high energy density.
Co-reporter:Linlin Wang, Huacheng Zhang, Zhe Yang, Jianjun Zhou, Liping Wen, Lin Li and Lei Jiang
Physical Chemistry Chemical Physics 2015 vol. 17(Issue 9) pp:6367-6373
Publication Date(Web):19 Jan 2015
DOI:10.1039/C4CP05915H
Heterogeneous nanochannel materials that endow new functionalities different to the intrinsic properties of two original nanoporous materials have wide potential applications in nanofluidics, energy conversion, and biosensors. Herein, we report novel, interesting hydrogel-composited nanochannel devices with regulatable ion rectification characteristics. The heterogeneous nanochannel devices were constructed by selectively coating the tip side, base side, or both sides of a single conical nanochannel membrane with thin agar hydrogel layers. The tunable ion current rectification of the nanochannels in the three different coating states was systematically demonstrated by current–voltage (I–V) curves. The asymmetric ionic transport property of the conical nanochannel was further strengthened in the tip-coating state and weakened in the base-coating state, whereas the conical nanochannel showed nearly symmetric ionic transport in the dual-coating state. Repeated experiments presented insight into the good stability and reversibility of the three coating states of the hydrogel–nanochannel-integrated systems. This work, as an example, may provide a new strategy to further design and develop multifunctional gel–nanochannel heterogeneous smart porous nanomaterials.
Co-reporter:Xiu-nan Yin;Jing Wang;Jian-jun Zhou 周建军;Lin Li 李林
Chinese Journal of Polymer Science 2015 Volume 33( Issue 12) pp:1721-1729
Publication Date(Web):2015 December
DOI:10.1007/s10118-015-1726-8
In this manuscript, an easy method of anchoring Au nanoparticles onto a polypropylene (PP) membrane to prepare a composite Au-PP membrane with catalytic activity was demonstrated. The surface of the PP membrane was first modified with a primary amine by mussel-inspired dopamine polymerization. Then, the modified PP membrane was used to reduce chloroauric acid to anchor Au nanoparticles onto the surface, forming a Au-PP membrane. The surface morphology and composition of the modified PP membrane were characterized with SEM, ATR-FTIR and XPS. The catalytic activity of the Au-PP membrane was also evaluated by the degradation of a model dye solution of methylene blue. The fabricated membrane shows excellent catalytic performance, and the catalytic activity can be effectively regenerated.
Co-reporter:Xi Jiang, Xiao Liu, Qi Liao, Xi Wang, Da-Dong Yan, Hong Huo, Lin Li and Jian-Jun Zhou
Soft Matter 2014 vol. 10(Issue 18) pp:3238-3244
Publication Date(Web):27 Jan 2014
DOI:10.1039/C3SM52975D
Poly(ethylene oxide) (PEO) single crystals were grown from dilute solution using a self-seeding method. The PEO single crystals with uniform dimensions, homogeneous chemical and physical properties were used as a simplified ultrathin film system to probe the interfacial properties of different substrates. In situ studying the annealing and melting behavior of PEO single crystals on the PAA, amorphous PEO and PVA substrates were carried out using an atomic force microscope (AFM) equipped with a hot stage. The interaction force between the PEO modified probe and various substrates was measured at different temperatures, and the universal dependence of the interaction force between the probe and polymer substrate on the temperature was demonstrated. The wetting and dewetting behavior of PEO melt on the PAA and amorphous PEO and PVA substrates were observed and the spreading coefficient (S) was proposed to prejudge the spreading behavior of a polymer ultra-thin film on a solid substrate according to the interaction force. Different melting points were found and the initial melting of the PEO single crystals occurred at 51, 54 and 61 °C on the PAA, PEO and PVA substrates, respectively. How the interfacial energy affects the melting point of single crystals was demonstrated, and the theoretical prediction agrees well with the experimental results.
Co-reporter:Yi-ning He;Xiao Liu;Qi Liao;Jian-jun Zhou 周建军
Chinese Journal of Polymer Science 2014 Volume 32( Issue 9) pp:1253-1259
Publication Date(Web):2014 September
DOI:10.1007/s10118-014-1504-z
Poly(ethylene oxide) multi-layer crystals were obtained and the re-crystallization behavior was studied to give insight into how melt thickness and temperature affect the lamellar orientation. For a special re-crystallization temperature, there exists a critical transition thickness range for the occurrence of edge-on lamellar orientation. Below the critical thickness, only flat-on lamellae were observed. While above the critical thickness, both flat-on and edge-on lamellae were found and the proportion of the edge-on lamellae increases with thickness. At low re-crystallization temperatures (below 30 °C), the critical transition thickness gradually increases from about 15 nm to 35 nm when the re-crystallization temperature was increased from 20 °C to 30 °C. However, when the re-crystallization temperature is above 30 °C, the critical transition thickness becomes constant. Our results demonstrated that the lamellar orientation could be specially modified by changing the melt thickness and re-crystallization temperature.
Co-reporter:Xi Jiang;Qi Liao;Zhaohui Wang;Chiming Chan;Lin Li
Journal of Polymer Science Part B: Polymer Physics 2013 Volume 51( Issue 11) pp:907-914
Publication Date(Web):
DOI:10.1002/polb.23281
ABSTRACT
We have developed a morphologic method to investigate the relaxation processing of the stretched polymer chains in melts, in which an atomic force microscope probe was used to shear the surface of an isotactic polypropylene melt to obtain the isolated shish-kebab structure. We present the results of the time dependence of length of the isolated shish-kebab structure and the stress dependence of the kebab density along the direction of shish in this paper. Our results demonstrate that the shear-oriented polymer melts show the relaxation dynamics of worm-like chain where the length deficit of the isolated shish-kebab structure is scaled with the relaxation time as a power of 1/3. The melting behavior of shish-kebab structure was also investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 907–914
Co-reporter:Yong Jiang, Li-Lung Lai, Jian-Jun Zhou
Microelectronics Reliability 2012 Volume 52(Issue 1) pp:159-164
Publication Date(Web):January 2012
DOI:10.1016/j.microrel.2011.08.008
Failure analysis (FA) at nanometer or micrometer scale on integrated circuit (IC) becomes progressively more challenging as the complexity of new IC devices increases and their sizes decrease. In this paper, conductive atomic force microscopy (CAFM) was employed as an alternative technique for single-bit failure analysis. Using CAFM current imaging, one can screen out each failure bit and locate its position quickly and simply by applying suitable bias during CAFM scanning. Furthermore, using CAFM current–voltage (I–V) measurements, one can acquire the full electrical characteristic of each failure bit, which is very useful to determine the associated mechanism of the physical defect. The results show that CAFM current imaging together with the I–V measurement can be a suitable candidate for FA at the single-bit level.Highlights► Conductive atomic force microscopy (CAFM) is an alternative for failure analysis. ► Each failure bit can be analyzed quickly and simply at a single-bit level. ► The position of each failure bit can be located by CAFM imaging. ► The electrical characteristic can be acquired by CAFM current–voltage measurements.
Co-reporter:Linlin Wang, Huacheng Zhang, Zhe Yang, Jianjun Zhou, Liping Wen, Lin Li and Lei Jiang
Physical Chemistry Chemical Physics 2015 - vol. 17(Issue 9) pp:NaN6373-6373
Publication Date(Web):2015/01/19
DOI:10.1039/C4CP05915H
Heterogeneous nanochannel materials that endow new functionalities different to the intrinsic properties of two original nanoporous materials have wide potential applications in nanofluidics, energy conversion, and biosensors. Herein, we report novel, interesting hydrogel-composited nanochannel devices with regulatable ion rectification characteristics. The heterogeneous nanochannel devices were constructed by selectively coating the tip side, base side, or both sides of a single conical nanochannel membrane with thin agar hydrogel layers. The tunable ion current rectification of the nanochannels in the three different coating states was systematically demonstrated by current–voltage (I–V) curves. The asymmetric ionic transport property of the conical nanochannel was further strengthened in the tip-coating state and weakened in the base-coating state, whereas the conical nanochannel showed nearly symmetric ionic transport in the dual-coating state. Repeated experiments presented insight into the good stability and reversibility of the three coating states of the hydrogel–nanochannel-integrated systems. This work, as an example, may provide a new strategy to further design and develop multifunctional gel–nanochannel heterogeneous smart porous nanomaterials.