The Experts below are selected from a list of 98577 Experts worldwide ranked by ideXlab platform
Hiromichi Kataura - One of the best experts on this subject based on the ideXlab platform.
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Large-scale single-chirality separation of single-wall carbon nanotubes by simple Gel Chromatography
Nature Communications, 2011Co-Authors: Huaping Liu, Daisuke Nishide, Takeshi Tanaka, Hiromichi KatauraAbstract:Large-scale separation of single-wall carbon nanotubes into populations of single chirality is a significant challenge in the practical application of nanotubes. Now, using multicolumn Gel Chromatography, the large-scale separation of 13 different carbon nanotube species is achieved.AbstractMonostructured single-wall carbon nanotubes (SWCNTs) are important in both scientific research and electronic and biomedical applications; however, the bulk separation of SWCNTs into populations of single-chirality nanotubes remains challenging. Here we report a simple and effective method for the large-scale chirality separation of SWCNTs using a single-surfactant multicolumn Gel Chromatography method utilizing one surfactant and a series of vertically connected Gel columns. This method is based on the structure-dependent interaction strength of SWCNTs with an allyl dextran-based Gel. Overloading an SWCNT dispersion on the top column results in the adsorption sites of the column becoming fully occupied by the nanotubes that exhibit the strongest interaction with the Gel. The unbound nanotubes flow through to the next column, and the nanotubes with the second strongest interaction with the Gel are adsorbed in this stage. In this manner, 13 different ( n , m ) species were separated. Metallic SWCNTs were finally collected as unbound nanotubes because they exhibited the lowest interaction with the Gel.
Go Matsumura - One of the best experts on this subject based on the ideXlab platform.
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Determination of Stokes radii and molecular masses of sodium hyaluronates by Sepharose Gel Chromatography
Journal of Chromatography A, 1992Co-Authors: Eiji Shimada, Go MatsumuraAbstract:Abstract On the basis of available volumes (Kav) of a chondroitin sulphate fraction and some proteins with known Stokes radii (R) in Sepharose (6B, 4B and 2B) Gel Chromatography, it was found that Ogston's equation correlating Kav with R was also applicable to Sepharose Gel in addition to the Sephadex Gel previously examined. Therefore, R values for sodium hyaluronate samples were determined in a similar manner to that already described for R values for hyaluronate oligosaccharides by Sephadex Gel Chromatography, using bovine serum albumin as a standard of known size and the radius (2.5 nm) of agarose chain forming the Gel networks. The molecular masses (M) of these samples, estimated from their intrinsic viscosities according to Mark-Houwink equations, were in the range 3.9 · 104−3.0 · 105. Their Stokes radii determined by Gel Chromatography were in the range 5.9–14.4 nm. A simple relationship of R = 0.030 M 1 2 was maintained for the hyaluronates with M below 1.3 · 105 (R = 11 nm). The plots of R against M 1 2 gave R = 4.82 + 0.0175 M 1 2 for M above 1.3 · 105. By use of these relationships, the molecular mass hyaluronate can be determined from its Stokes radius under the experimental conditions.
Huaping Liu - One of the best experts on this subject based on the ideXlab platform.
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Ethanol-assisted Gel Chromatography for single-chirality separation of carbon nanotubes
Nanoscale, 2015Co-Authors: Xiang Zeng, Huaping Liu, Xiao Zhang, Naigen Zhou, Weiya Zhou, Sishen XieAbstract:Surfactants or polymers are usually used for the liquid processing of carbon nanotubes for their structure separation. However, they are difficult to remove after separation, affecting the intrinsic properties and applications of the separated species. Here, we report an ethanol-assisted Gel Chromatography for the chirality separation of single-walled carbon nanotubes (SWCNTs), in which ethanol is employed to finely tune the density/coverage of sodium dodecyl sulfate (SDS) on nanotubes, and thus the interactions between SWCNTs and an allyl dextran-based Gel. Incrementally increasing the ethanol content in a low-concentration SDS eluent leads to successive desorption of the different structure SWCNTs adsorbed on the Gel, and to achieve multiple distinct (n, m) single-chirality species. The use of ethanol enables the working concentration of SDS to be reduced dramatically and also avoids the introduction of other surfactants or chemical reagents. More importantly, ethanol can be easily removed after separation. The ability of ethanol to tune the interactions between SWCNTs and the Gel also gives a deeper insight into the separation mechanism of SWCNTs using Gel Chromatography.
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Large-scale single-chirality separation of single-wall carbon nanotubes by simple Gel Chromatography
Nature Communications, 2011Co-Authors: Huaping Liu, Daisuke Nishide, Takeshi Tanaka, Hiromichi KatauraAbstract:Large-scale separation of single-wall carbon nanotubes into populations of single chirality is a significant challenge in the practical application of nanotubes. Now, using multicolumn Gel Chromatography, the large-scale separation of 13 different carbon nanotube species is achieved.AbstractMonostructured single-wall carbon nanotubes (SWCNTs) are important in both scientific research and electronic and biomedical applications; however, the bulk separation of SWCNTs into populations of single-chirality nanotubes remains challenging. Here we report a simple and effective method for the large-scale chirality separation of SWCNTs using a single-surfactant multicolumn Gel Chromatography method utilizing one surfactant and a series of vertically connected Gel columns. This method is based on the structure-dependent interaction strength of SWCNTs with an allyl dextran-based Gel. Overloading an SWCNT dispersion on the top column results in the adsorption sites of the column becoming fully occupied by the nanotubes that exhibit the strongest interaction with the Gel. The unbound nanotubes flow through to the next column, and the nanotubes with the second strongest interaction with the Gel are adsorbed in this stage. In this manner, 13 different ( n , m ) species were separated. Metallic SWCNTs were finally collected as unbound nanotubes because they exhibited the lowest interaction with the Gel.
Eiji Shimada - One of the best experts on this subject based on the ideXlab platform.
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Determination of Stokes radii and molecular masses of sodium hyaluronates by Sepharose Gel Chromatography
Journal of Chromatography A, 1992Co-Authors: Eiji Shimada, Go MatsumuraAbstract:Abstract On the basis of available volumes (Kav) of a chondroitin sulphate fraction and some proteins with known Stokes radii (R) in Sepharose (6B, 4B and 2B) Gel Chromatography, it was found that Ogston's equation correlating Kav with R was also applicable to Sepharose Gel in addition to the Sephadex Gel previously examined. Therefore, R values for sodium hyaluronate samples were determined in a similar manner to that already described for R values for hyaluronate oligosaccharides by Sephadex Gel Chromatography, using bovine serum albumin as a standard of known size and the radius (2.5 nm) of agarose chain forming the Gel networks. The molecular masses (M) of these samples, estimated from their intrinsic viscosities according to Mark-Houwink equations, were in the range 3.9 · 104−3.0 · 105. Their Stokes radii determined by Gel Chromatography were in the range 5.9–14.4 nm. A simple relationship of R = 0.030 M 1 2 was maintained for the hyaluronates with M below 1.3 · 105 (R = 11 nm). The plots of R against M 1 2 gave R = 4.82 + 0.0175 M 1 2 for M above 1.3 · 105. By use of these relationships, the molecular mass hyaluronate can be determined from its Stokes radius under the experimental conditions.
Daisuke Nishide - One of the best experts on this subject based on the ideXlab platform.
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Large-scale single-chirality separation of single-wall carbon nanotubes by simple Gel Chromatography
Nature Communications, 2011Co-Authors: Huaping Liu, Daisuke Nishide, Takeshi Tanaka, Hiromichi KatauraAbstract:Large-scale separation of single-wall carbon nanotubes into populations of single chirality is a significant challenge in the practical application of nanotubes. Now, using multicolumn Gel Chromatography, the large-scale separation of 13 different carbon nanotube species is achieved.AbstractMonostructured single-wall carbon nanotubes (SWCNTs) are important in both scientific research and electronic and biomedical applications; however, the bulk separation of SWCNTs into populations of single-chirality nanotubes remains challenging. Here we report a simple and effective method for the large-scale chirality separation of SWCNTs using a single-surfactant multicolumn Gel Chromatography method utilizing one surfactant and a series of vertically connected Gel columns. This method is based on the structure-dependent interaction strength of SWCNTs with an allyl dextran-based Gel. Overloading an SWCNT dispersion on the top column results in the adsorption sites of the column becoming fully occupied by the nanotubes that exhibit the strongest interaction with the Gel. The unbound nanotubes flow through to the next column, and the nanotubes with the second strongest interaction with the Gel are adsorbed in this stage. In this manner, 13 different ( n , m ) species were separated. Metallic SWCNTs were finally collected as unbound nanotubes because they exhibited the lowest interaction with the Gel.
