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1. Primitive path analysis of linear polymer embedded in post array | |||
HOU Jixuan | |||
Chemistry 24 April 2017 | |||
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Abstract:In this paper, we present an extensive set of simulation results for the relaxation processes of linear polymer chains embedded in post arrays using Monte Carlo algorithm. The data allow us to explore the crossover of chain dynamics from single-chain regime to entangled regime. Using primitive path analysis, the statistical information of the system, including the average value and the fluctuation of the length of primitive path, is also obtained. We have performed a clear test on Doi's theory on contour length fluctuation and we find excellent agreement for Doi's theory in entangled regime. | |||
TO cite this article:HOU Jixuan. Primitive path analysis of linear polymer embedded in post array[OL].[24 April 2017] http://en.paper.edu.cn/en_releasepaper/content/4728664 |
2. A study on the conformation transition of polyacrylic acid in its aqueous solution by fluorescence correlation spectroscopy | |||
JIA Pengxiang,ZHAO Jiang | |||
Chemistry 17 December 2015 | |||
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Abstract:In this paper, the conformation transition of an annealed polyelectrolytes, polyacrylic acid (PAA), was studied by fluorescence correlation spectroscopy in its aqueous solution. The influence of pH, counterions concentration and valence on the conformation transition was investigated. The results revealed that PAA undergoes a continuous conformational transition between pH 6 and 3 from an extended coiled structure to a collapsed globule conformation. The conformational transition can also be achieved by increasing the counterions concentration. The dependence of hydrodynamic radius on the Debye screening length are determined. The results were compared with quenched polyelectrolytes. "Ion-bridging effect" was founded when added multi-valent counterion. A series about the interaction ability of multivalent counterions and PAA was founded: La3+>Ba2+>Sr2+≈Ca2+>Mg2+. An evidence of re-entrant transition of PAA with Mg2+ ion was also discovered. | |||
TO cite this article:JIA Pengxiang,ZHAO Jiang. A study on the conformation transition of polyacrylic acid in its aqueous solution by fluorescence correlation spectroscopy[OL].[17 December 2015] http://en.paper.edu.cn/en_releasepaper/content/4672091 |
3. Furan-BDOPV Donor-Acceptor Polymers with Planar Conformations for High-Performance Organic Field-Effect Transistors under Ambient Conditions | |||
LU Ru-Qiang,YAN Xiao-Yun,XUAN Wei,SHI Pei-Chen,PENG Pi-Xian,CHEN Rui,ZHANG Qiu-Lian,SHI Chang-Xia,WU Fan,WU Peng,ZHENG Yu-Qing,DOU Jin-Hu,PEI Jian,CAO Xiao-Yu | |||
Chemistry 10 December 2015 | |||
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Abstract:Benzodifurandione-based oligo(p-phenylene vinylene) (BDOPV)-based donor-acceptor (D-A) copolymers adopted planar conformations were synthesized using 2,2'-bifuran (2F) or benzo[1,2-b:4,5-b']difuran (BDF) as donors. Under ambient conditions, BDOPV-2F showed a high electron mobility of up to 1.83 cm2 v-1 s-1, the highest among furan-containing polymers (even higher than its thiophene counterparts), and a hole mobility of 0.026 cm2 v-1 s-1, whereas BDOPV-BDF showed an electron mobility of 0.41 cm2 v-1 s-1 and a hole mobility of 0.0084 cm2 v-1 s-1. The planar conformations play an important role in charge carriers transport. | |||
TO cite this article:LU Ru-Qiang,YAN Xiao-Yun,XUAN Wei, et al. Furan-BDOPV Donor-Acceptor Polymers with Planar Conformations for High-Performance Organic Field-Effect Transistors under Ambient Conditions[OL].[10 December 2015] http://en.paper.edu.cn/en_releasepaper/content/4669019 |
4. Kinetics and chain conformation of a ring polymer adsorbed to a flat surface | |||
SHENG Jun-Fang, LUO Kaifu | |||
Chemistry 13 January 2014 | |||
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Abstract:We investigate the adsorption kinetics of a flexible ring polymer chain with one bead grafted on a flat solid surface and the conformation of the adsorbed chain using three-dimensional (3D) Langevin dynamics simulations. We find that, compared with linear chains, ring polymers are adsorbed faster in regimes of both weak and strong adsorption and are adsorbed more in regime of weak adsorption. The radius of gyration in the parallel direction to the surface, $R_{gparallel}$, is always smaller for a ring polymer than that for the linear one of the same chain length $N$. For both ring and linear chains, the scaling exponent of $R_{gparallel}$ with $N$ depends on the interaction between the chain and the surface. As observed in previous experiments, it is between $ u_{3D}$ and $ u_{2D}$ (3D and 2D Flory exponents) in the regime of weak adsorption, while it is between 0.5 and $ u_{3D}$ in the regime of strong adsorption. For the irreversible adsorption, the adsorption time $ au$ scales with chain length $N$ as $ au sim N^{1+ u_{3D}}$ for both ring and linear chains, and for the same $N$ the ratio of $ au$ for the ring polymer and the linear chain is about 0.57. | |||
TO cite this article:SHENG Jun-Fang, LUO Kaifu. Kinetics and chain conformation of a ring polymer adsorbed to a flat surface[OL].[13 January 2014] http://en.paper.edu.cn/en_releasepaper/content/4581766 |
5. Adsorption transition of a ring polymer at an attractive surface | |||
SHENG Jun-Fang,LUO Kaifu | |||
Chemistry 01 January 2014 | |||
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Abstract:We investigate the adsorption dynamics of a flexible ring polymer chain with one bead grafted to a flat solid surface and the conformation of the adsorbed chain using 3D Langevin dynamics simulations.Compared with the linear chain, the ring chain has the same critical adsorption point (CAP). At the CAP, the crossover exponent of the number of adsorbed beads with chain length is about 0.46 for both ring and linear chains, which is smaller than 0.5, in agreement with the current best estimated value 0.48. At the CAP, ring polymers are adsorbed on the surface more than linear chains, which agrees with experiments, and the ratio is about 1.2. In addition, We further observe that, compared with linear chains, the adsorption of ring polymers is faster to reach equilibrium state. | |||
TO cite this article:SHENG Jun-Fang,LUO Kaifu. Adsorption transition of a ring polymer at an attractive surface[OL].[ 1 January 2014] http://en.paper.edu.cn/en_releasepaper/content/4579541 |
6. Phase separation and crystallization of binary nanoparticles induced by polymer brushes | |||
ZHANG Dong,ZHANG Linxi | |||
Chemistry 10 December 2012 | |||
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Abstract:The aggregation behaviors and phase separation of binary nanoparticles in semiflexible polymer brushes are explored by using molecular dynamics simulations. The conformations of the binary nanoparticles/brushes mixtures are very sensitive to the size ratio of nanoparticles and the attractive interactions between nanoparticles and polymer brushes. The phase separation of the binary nanoparticles is observed at a relatively strong attractive interaction under the effect of inter-nanoparticle depletion attractions provided by polymer brushes. Furthermore, the crystallization of small nanoparticles occurs at a strong interaction and a hexagonal close-packed-like (hcp-like) ordered structure is formed. The present results may promise a new approach for controlling the self-assembling behavior of nanoparticles and constructing a better macroscopic performance of the material. | |||
TO cite this article:ZHANG Dong,ZHANG Linxi. Phase separation and crystallization of binary nanoparticles induced by polymer brushes[OL].[10 December 2012] http://en.paper.edu.cn/en_releasepaper/content/4500547 |
7. Inorganic-Salt-Induced Morphological Transformation of Semicrystalline Micelles of PCL-b-PEO Block Copolymer in Aqueous Solution | |||
HE Wei-na,XU Jun-ting | |||
Chemistry 25 September 2012 | |||
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Abstract:The effect of inorganic salt at concentrations typical of a biological environment on the Micellar morphology of semicrystalline PCL-b-PEO in aqueous solution is investigated. The salt is introduced either by dialysis of a THF solution against an aqueous solution of the salt or by adding it into an aqueous solution containing preformed micelles. The inorganic salt can induce sphere-to-rod or sphere-to-lamella transformations of the PCL-b-PEO micelles in aqueous solution, affected by the length of the PCL block, the method of salt-adding and the concentration of inorganic salts. The inorganic salt induces ''salting-out'' of the PEO block, leading to a decrease in the reduced tethering density of the corona in the micelles. | |||
TO cite this article:HE Wei-na,XU Jun-ting. Inorganic-Salt-Induced Morphological Transformation of Semicrystalline Micelles of PCL-b-PEO Block Copolymer in Aqueous Solution[OL].[25 September 2012] http://en.paper.edu.cn/en_releasepaper/content/4490188 |
8. Effect of pH on the Micellar Morphology of Semicrystalline PCL-b-PEO block Copolymers in Aqueous Solution | |||
HE Wei-na,XU Jun-ting | |||
Chemistry 19 September 2012 | |||
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Abstract:The effect of pH on the micellar morphology of a semicrystalline poly(ε-caprolactone)-block -poly(ethylene oxide) block copolymer in aqueous solution is investigated. Spherical micelles are formed in neutral and acidic solutions. However, addition of alkali to the neutral micellar solution triggers a sphere-to-cylinder transformation of the micellar morphology. The micelles are stable in both neutral and acidic solutions, but the size of the micelles becomes gradually larger in the alkali solution. This phenomenon is interpreted in terms of the effect of pH value on the reduced tethering density of the corona in the semicrystalline micelles. | |||
TO cite this article:HE Wei-na,XU Jun-ting. Effect of pH on the Micellar Morphology of Semicrystalline PCL-b-PEO block Copolymers in Aqueous Solution[OL].[19 September 2012] http://en.paper.edu.cn/en_releasepaper/content/4490029 |
9. Influence of SiO2 nanoparticles on the phase behavior of polystyrene/poly(vinyl methyl ether) blends under oscillatory shear flow | |||
LI Nan,HUANG Yajiang,LI Guangxian | |||
Chemistry 26 March 2012 | |||
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Abstract:The introduction of nanoparticles into polymer blends has been proved to be an effective way in tailoring their microstructure and properties. However, the influence of nanoparticles on the phase behavior of blends under flow still remains unclear. In this study, the effects of SiO2 nanoparticles on the thermodynamics of polystyrene (PS)/poly(vinyl methyl ether) (PVME) blends with near-critical and off-critical compositions were investigated under oscillatory shear flow. It was found that the phase behavior of SiO2-filled PS/PVME blends was determined with the oscillatory shear frequency and concentration of SiO2 nanoparticles. The shear-induced demixing (SID) behavior was totally suppressed in PS/PVME blends with higher SiO2 nanoparticle loading. However, less SiO2 nanoparticles were needed in the off-critical blend than in the near critical blend in order to eliminate the SID behavior. | |||
TO cite this article:LI Nan,HUANG Yajiang,LI Guangxian. Influence of SiO2 nanoparticles on the phase behavior of polystyrene/poly(vinyl methyl ether) blends under oscillatory shear flow[OL].[26 March 2012] http://en.paper.edu.cn/en_releasepaper/content/4473166 |
10. Elastic behavior of polymer chains | |||
LU Teng,Chen Tao,Liang Haojun | |||
Chemistry 14 January 2009 | |||
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Abstract:The elastic behavior of the polymer chain has been investigated in a three-dimensional off-lattice model. We sample enough conformations of each kind of polymer chain by using Monte Carlo Algorithm, then analyse them with the non-Gaussian theory of rubberlike elasticity, and make statistical process at last. Through observing the effect of the chain flexibility and the stretching ratio on the mean-square end-to-end distance, the average energy, the average Helmholtz free energy, the elastic force, the contribution of energy to the elastic force, and the entropy contribution to elastic force of the polymer chain, we find that a rigid polymer chain is much easier to be stretched than a flexible polymer chain. And a rigid polymer chain will become difficult to be stretched only at a quite high stretching ratio because of the effect of the entropy contribution. These results of our simulation calculation may explain some of the macroscopic phenomena of polymer and biomacromoleculer elasticity. | |||
TO cite this article:LU Teng,Chen Tao,Liang Haojun . Elastic behavior of polymer chains[OL].[14 January 2009] http://en.paper.edu.cn/en_releasepaper/content/27796 |
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