With the rapid development of nanotechnology, many kinds of metal oxide nanoparticles have been and are being used in biological and medical fields of industry and scientific *** public unavoidably exposes to the envi...
详细信息
With the rapid development of nanotechnology, many kinds of metal oxide nanoparticles have been and are being used in biological and medical fields of industry and scientific *** public unavoidably exposes to the environment of different kinds of nanoparticles, whose effect on the biological system is thereby becoming a critical ***, the interactions of nanoparticles with cells, the smallest building blocks of tissues and organs, are studied in terms of cellular uptake process, localization inside cells, exocytosis, cytotoxicity, genotoxicity and the potential influences on cell cycle, functions, phenotypes after particles uptake.
Synthetic single crystals are usually homogeneous solids. Biogenic single crystals, however, can incorporate biomacromolecules and become inhomogeneous solids so that their properties are also extrinsically regulated ...
详细信息
Synthetic single crystals are usually homogeneous solids. Biogenic single crystals, however, can incorporate biomacromolecules and become inhomogeneous solids so that their properties are also extrinsically regulated by the incorporated materials. The discrepancy between the properties of synthetic and biogenic single crystals leads to the idea to modify the internal structure of synthetic crystals to achieve nonintrinsic properties by incorporation of foreign material. Intrinsically colorless and diamagnetic calcite single crystals are turned into colored and paramagnetic solids, through incorporation of Au and Fe 3 O 4 nanoparticles without significantly disrupting the crystalline lattice of calcite. The crystals incorporate the nanoparticles and gel fibers when grown in agarose gel media containing the nanoparticles, whereas the solution‐grown crystals do not. As such, our work extends the long‐history gel method for crystallization into a platform to functionalize single‐crystalline materials.
To improve the colloidal stability of bovine serum albumin （BSA） nanoparticles （hiPs） in diverse mediums, poly（allylamine hydrochloride） （PAH）/sodium poly（4-styrene sulfonate） （PSS） multilayers and poly（a...
详细信息
To improve the colloidal stability of bovine serum albumin （BSA） nanoparticles （hiPs） in diverse mediums, poly（allylamine hydrochloride） （PAH）/sodium poly（4-styrene sulfonate） （PSS） multilayers and poly（allylamine hydrochloride）-graft-poly（ethylene glycol） （PAH-g-PEG） coating were coated on the surface of BSA NPs. Stabilities of the BSA NPs in diverse mediums with different surfaces were detected by dynamic light scattering （DLS）. Multilayers and PAH-g-PEG coated BSA NPs can be well dispersed in various mediums with a narrow polydispersity index （PDI）. The BSA NPs with the highest surface density of PEG show the best stability. The multilayers and PAH-g-PEG coating do not deter the pH-dependent loading and release property of BSA NPs. At pH 9, the encapsulation efficiency of doxorubicin reaches almost 99%, and the release rate at pH 5.5 is significantly higher than that at pH 7.4.
Ethylene/propylene-random-copolymer （PPR）/clay nanocomposites were prepared by two-stage melt blending. Four types of compatibilizers, including an ethylene-octene copolymer grafted maleic anhydride （POE-g-MA） and...
详细信息
Ethylene/propylene-random-copolymer （PPR）/clay nanocomposites were prepared by two-stage melt blending. Four types of compatibilizers, including an ethylene-octene copolymer grafted maleic anhydride （POE-g-MA） and three maleic-anhydride-grafted polypropylenes （PP-g-MA） with different melt flow indexes （MFI）, were used to improve the dispersion of organic clay in matrix. On the other hand, the effects of organic montmorillonite （OMMT） content on the nanocomposite structure in terms of clay dispersion in PPR matrix, thermal behavior and tensile properties were also studied. The X-ray diffraction （XRD） and transmission electron microscopy （TEM） results show that the organic clay layers are mainly intercalated and partially exfoliated in the nanocomposites. Moreover, a PP-g-MA compatibilizer （compatibilizer B） having high MFI can greatly increase the interlayer spacing of the clay as compared with other compatibilizers. With the introduction of compatibilizer D （POE-g-MA）, most of the clays are dispersed into the POE phase, and the shape of the dispersed OMMT appears elliptic, which differs from the strip of PP-g-MA. Compared with virgin PPR, the Young＇s modulus of the nanocomposite evidently increases when a compatibilizer C （PP-g-MA） with medium MFI is used. For the nanocomposites with compatibilizer B and C, their crystallinities （Xc） increase as compared with that of the virgin PPR. Furthermore, the increase of OMMT loadings presents little effect on the melt temperature （Tc） of the PPR/OMMT nanocomposites, and slight effect on their crystallization temperature （Tc）. Only compatibilizer B can lead to a marked increases in crystallinity and Tc of the nanocomposite when the OMMT content is 2 wt%.
Electrospun material with bio-inspired ordered architectures and patterns is very interesting,yet remains a *** report here that nanofibrous mats with bird＇s nest patterned structures can be directly electrospun from...
详细信息
Electrospun material with bio-inspired ordered architectures and patterns is very interesting,yet remains a *** report here that nanofibrous mats with bird＇s nest patterned structures can be directly electrospun from chlorinated polypropylene solutions doped with an ionic *** solution viscosity and the ionic liquid content are two dominant factors to influence the topological morphology of the nanofibrous *** patterned structures can be further modulated by the collection time of electrospinning,the humidity of environment and the design of *** suggest the electrostatic repulsion between the residual charges of the mat surface and the upcoming nanofibers plays a key role in the formation of the bird＇s nest patterns.
We report a novel strategy to study the chain dynamics of poly(acrylic acid)(PAA)in a relative concentrated solution(1.0 g/L).The strategy is based on the fluorescent probe(DCTPE)with unique aggregation-induced emissi...
详细信息
We report a novel strategy to study the chain dynamics of poly(acrylic acid)(PAA)in a relative concentrated solution(1.0 g/L).The strategy is based on the fluorescent probe(DCTPE)with unique aggregation-induced emission(AIE)*** DCTPE molecules are non-emissive in aqueous solution,but they become highly emissive when trapped in polymer *** fluorescence intensity is proportional to the efficiency of trapping DCTPE molecules in polymer *** correlation the change of fluorescence intensity with the variation of pH value(from1.78 to 12.06),the PAA chain’s dynamics in the relatively concentrated solution have been elucidated into three *** the pH range from 12.06 to 6.0,PAA chains take an extended and non-folding *** pH from 6.0 to 3.86,PAA chains are partially protonated and loosely packed polymer coils are *** lowering the pH value of the solution(from 3.86 to 1.78),protonated segments dominate the PAA chains,and at the same time,the intermolecular hydrogen bonding takes effect,thus the polymer chains posses in the conformation of more compact coils.
暂无评论