共查询到4条相似文献,搜索用时 0 毫秒
1.
Kazuhiko Kitano Yuuki Inoue Ryosuke Matsuno Madoka Takai Kazuhiko Ishihara 《Colloids and surfaces. B, Biointerfaces》2009,74(1):350-357
For preparing a “highly lubricated biointerface”, which has both excellent lubricity and biocompatibility, we investigated the factors responsible for resistance to friction during polymer grafting. We prepared poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), poly(2-hydroxyethyl methacrylate) (PHEMA), and poly(methyl methacrylate) (PMMA) brush layers with high graft density and well-controlled thickness using atom transfer radical polymerization (ATRP). We measured the water absorptivity in the polymer brush layers and the viscoelasticity of the polymer-hydrated layers using a quartz crystal microbalance with dissipation monitoring (QCM-D) measurements. The PMPC brush layer had the highest water absorptivity, while the PMPC-hydrated layer had the highest fluidity. The friction properties of the polymer brush layers were determined in air, water, and toluene by atomic force microscopy (AFM). The friction on each polymer brush decreased only when a good solvent was chosen for each polymer. In conclusion, the brush layer possessing high water absorptivity and fluidity in water contributes to reduce friction. PMPC grafting is an effective and promising method for obtaining highly lubricated biointerfaces. 相似文献
2.
Fakhrullin RF Vinter VG Zamaleeva AI Matveeva MV Kourbanov RA Temesgen BK Ishmuchametova DG Abramova ZI Konovalova OA Salakhov MK 《Analytical and bioanalytical chemistry》2007,388(2):367-375
We report the development of a novel quartz crystal microbalance immunosensor with the simultaneous measurement of resonance
frequency and motional resistance for the detection of antibodies to double-stranded DNA (dsDNA). The immobilization of poly(l-lysine) and subsequent complexation with DNA resulted in formation of a sensitive dsDNA-containing nanofilm on the surface
of a gold electrode. Atomic force microscopy has been applied for the characterization of a poly(l-lysine)–DNA film. After the blocking with bovine serum albumin, the immunosensor in flow-injection mode was used to detect
the antibodies to dsDNA in purified protein solutions of antibodies to dsDNA and to single-stranded DNA, monoclonal human
immunoglobulin G, DNase I and in blood serum of patients with bronchial asthma and systemic lupus erythematosus. Experimental
results indicate high sensitivity and selectivity of the immunosensor.
In memoriam Prof. Victor G. Vinter 相似文献
3.
The adsorption-desorption of silica nanoparticles(NPs) on poly(ethylene glycol)(PEG) grafted onto gold(Au) substrate was studied by quartz crystal microbalance with dissipation monitoring(QCM-D) technique. The results of frequency and dissipation show that SiO2 NPs can be adsorbed strongly on PEG-SH brushes at pH of 9.6, and a new dense and rigid construction is formed. Adjusting the pH from 9.6 to 12.3 resulted in the desorption of silica NPs from the PEG brushes because of a significant weakening of the hydrogen bond between the silica NPs and PEG chains. In addition, the viscoelastic properties of the system during the adsorption-desorption process were also analyzed via the relationship between the normalized frequency(Δf/n) and mass. And the corresponding atomic force microscopy(AFM) images also exhibit morphological changes during the above process, consistent with the changes in viscoelasticity. 相似文献
4.
Cellulose nanofibrils—adsorption with poly(amideamine) epichlorohydrin studied by QCM-D and application as a paper strength additive 总被引:1,自引:0,他引:1
In this paper cellulose nanofibrils were used together with a cationic polylelectrolyte, poly(amideamine) epichlorohydrin
(PAE), to enhance the wet and the dry strength of paper. The adsorption of nanofibrils and PAE on cellulose model surfaces
was studied using quartz crystal microbalance with dissipation (QCM-D) and atomic force microscopy (AFM). The differences
in fibril and polyelectrolyte adding strategies onto cellulose fibres were studied by comparing layer-structures and nano-aggregates
formed by the nanofibrils and PAE. The results showed that when PAE was first adsorbed on the model fibre surface a uniform
and viscous layer of nanofibrils could be adsorbed. When PAE and nanofibrils were adsorbed as cationic aggregates a non-uniform
and more rigid layer was adsorbed. Paper sheets were prepared using both the bi-layer and nano-aggregate adding strategy of
the nanofibrils and PAE. When PAE and nanofibrils were adsorbed on pulp fibres as a bi-layer system significant increase in
both wet and dry tensile strength of paper could be achieved even at low added amounts of PAE. When the substances were added
as nano-aggregates the improvements in paper strength properties were not as significant. Bulk and surface nitrogen content
analyses of the paper samples showed that the adding strategy does not affect the total adsorbed amount of PAE but it has
a strong effect on distribution of substances in the paper matrix which has a crucial effect on paper wet and dry strength
development. 相似文献