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991.
992.
《Journal of Dispersion Science and Technology》2013,34(3-4):305-341
Abstract Plasma treatment of polymers encompasses a variety of plasma technologies and polymeric materials for a wide range of applications and dates back to at least the 1960s. In this article we provide a brief review of the United States patent literature on plasma surface modification technologies and a brief review of the scientific literature on investigations of the effects of plasma treatment, the nature of the plasma environment, and the mechanisms that drive the plasma–surface interaction. We then discuss low‐radio‐frequency capacitively coupled nitrogen plasmas and their characteristics, suggesting that they provide significant plasma densities and populations of reactive species for effective plasma treatments on a variety of materials, particularly when placing the sample surface in the cathode sheath region. We further discuss surface chemical characterization of treated polymers, including some results on polyesters treated in capacitively coupled nitrogen plasmas driven at 40 kHz. Finally, we connect plasma characterization with surface chemical analysis by applying a surface sites model to nitrogen uptake of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN) treated in a 40 kHz nitrogen plasma. This example serves to suggest an interesting practical approach to comparisons of plasma treatments. In addition, it suggests an approach to defining the investigations required to conclusively identify the underlying treatment mechanisms. 相似文献
993.
994.
This paper has improved Hickman's nonadiabatic collision model by substituting Hickman's constant velocity classical straight line trajectory approximation with the solution of motion equation mR=?dV(R)/dR, and has calculated the cross sections of ion-pair formation Cs+O2→Cs++O?2 with the improved nonadiabatic collision model (INCM). A comparison of our results with other theoretical and experimental results has been made. 相似文献
995.
996.
Chen D Heberling MS Nakata M Hough LE Maclennan JE Glaser MA Korblova E Walba DM Watanabe J Clark NA 《Chemphyschem》2012,13(1):155-159
The B4 liquid crystal phase of bent-core molecules, a smectic phase of helical nanofilaments, is one of the most complex hierarchical self-assemblies in soft materials. We describe the layer topology of the B4 phase of mesogens in the P-n-OPIMB homologous series near the liquid crystal/glass interface. Freeze-fracture transmission electron microscopy reveals that the twisted layer structure of the bulk is suppressed, the layers instead forming a structure with periodic layer undulations, with the topography depending on the distance from the glass. The surface layer structure is modeled as parabolic focal conic arrays generated by equidistant parabolas whose foci are defect lines along the glass surface. Nucleation and growth of toric focal conics near the glass substrate is also observed. Although the growth of twisted nanofilaments, the usual manifestation of structural chirality in the B4 phase, is suppressed near the surface, the smectic layers are intrinsically chiral, and the helical filaments that form on top of them grow with specific handedness. 相似文献
997.
Sarkar S Bekyarova E Haddon RC 《Angewandte Chemie (International ed. in English)》2012,51(20):4901-4904
The Kolbe electrochemical oxidation strategy has been utilized to achieve an efficient quasireversible electrochemical grafting of the α-naphthylmethyl functional group to graphene. The method facilitates reversible bandgap engineering in graphene and preparation of electrochemically erasable organic dielectric films. The picture shows Raman D-band maps of both systems. 相似文献
998.
Larson RG 《Angewandte Chemie (International ed. in English)》2012,51(11):2546-2548
Not your cup of tea? "Coffee rings" of spherical colloidal particles are left behind after water droplets resting on surfaces have dried out. This controlled evaporation of colloidal solutions can be exploited to deposit material in regular patterns. It is now shown that if spherical colloids are replaced by slightly elongated ones, the coffee ring is not formed and is replaced by an even more uniform deposition. 相似文献
999.
Sun Hye Hwang Jongmin Roh Prof. Dr. Jyongsik Jang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(39):13120-13126
Enhanced harvesting of visible light is vital to the development of highly efficient dye‐sensitized solar cells (DSSCs). Nanosilver‐decorated TiO2 nanofibers (Ag@TiO2 NFs) were synthesized by depositing chemically reduced Ag ions onto the surface of electrospun TiO2 nanofibers (TiO2 NFs). The prepared Ag@TiO2 NFs were coated with SiO2 (SiO2@Ag@TiO2 NFs) by using PVP as coupling agent for protecting corrosion of Ag nanoparticle by I?/${{\rm I}{{- \hfill \atop 3\hfill}}}$ solution. The fabricated SiO2@Ag@TiO2 NFs demonstrated a synergistic effect of light scattering and surface plasmons, leading to an enhanced light absorption. Moreover, an anode consisting of SiO2@Ag@TiO2 NFs incorporating TiO2 nanoparticles (NPs) increased light harvesting without substantially sacrificing dye attachment. The power conversion efficiency increased from 6.8 to 8.7 % for a thick film (10 μm), that is, 28 %. These results suggest that SiO2@Ag@TiO2 NFs are promising materials for enhanced light absorption in dye‐sensitized solar cells. 相似文献
1000.
Akira Kawashima Prof. Dr. Takayuki Nakanishi Prof. Dr. Tamaki Shibayama Prof. Dr. Seiichi Watanabe Prof. Dr. Koji Fujita Prof. Dr. Katsuhisa Tanaka Prof. Dr. Hitoshi Koizumi Prof. Dr. Koji Fushimi Prof. Dr. Yasuchika Hasegawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(43):14438-14445
Remarkable magneto‐optical properties of a new isolator material, that is, europium sulfide nanocrystals with gold (EuS–Au nanosystem), has been demonstrated for a future photo‐information technology. Attachment of gold particles that exhibit surface plasmon resonance leads to amplification of the magneto‐optical properties of the EuS nanocrystals. To construct the EuS–Au nanosystems, cubic EuS and spherical Au nanocrystals have been joined by a variety of organic linkers, that is, 1,2‐ethanedithiol (EDT), 1,6‐hexanedithiol (HDT), 1,10‐decanedithiol (DDT), 1,4‐bisethanethionaphthalene (NpEDT), or 1,4‐bisdecanethionaphthalene (NpDDT) . Formation of these systems was observed by XRD, TEM, and absorption spectra measurements. The magneto‐optical properties of the EuS–Au nanosystem have been characterized by using Faraday rotation spectroscopy. The Faraday rotation angle of the EuS–Au nanosystem is dependent on the Au particle size and interparticle distance between EuS and Au nanocrystals. Enhancement of the Faraday rotation of EuS–Au nanosystems was observed. The spin configuration in the excited state of the EuS–Au nanosystem was also investigated using photo‐assisted electron paramagnetic resonance. 相似文献