Boron nitride nanotubes are noncytotoxic and can be functionalized for interaction with proteins and cells.
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ABSTRACT:
SUBMITTER: Chen X
PROVIDER: S-EPMC2657038 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Boron nitride nanotubes (BNNTs) are electrically insulating nanoparticles that display highly competitive elastic modulus and thermal conductivity. Long presented as potential fillers for nanocomposite applications, their poor dispersibility in most commodity polymers has, however, limited their spread. In this work, the chemical affinity of purified BNNTs, measured in terms of Hansen solubility parameters (HSP), were obtained through sedimentation tests in a wide set of organic solvents, taking into account relative sedimentation time. The parameters obtained were {δ d; δ p; δ h} = {16.8; 10.7; 14.7} ± {0.3; 0.9; 0.3} MPa1/2, with a Hildebrand parameter, δ t = 24.7 MPa1/2 and a sphere radius of 5.4 MPa1/2. The solubility parameters were determined considering complete dispersion of the purified nanomaterial, as well as the viscosity and density of the host solvent. These factors, combined with the high purity of the BNNTs, are crucial to minimize the uncertainty of the HSP characterization. Such refined values provide necessary insights both to optimize the solvent casting of unmodified BNNTs, and to orient the surface modification efforts that would be needed to integrate these nanomaterials into a wider range of host matrices.
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Project description:A method has been developed to slice boron nitride nanotubes BNNTs under continuous flow in a vortex fluidic device (VFD), along with a method to partially purify the as received BNNT containing material. The latter involves heating the BNNTs to 600 °C followed by dispersing in a 1 : 3 isopropyl alcohol (IPA) and water mixture at 100 °C. The VFD mediated slicing of the BNNTs comprises irradiating the rapidly rotating glass tube (20 mm OD) with a pulsed Nd:YAG laser. Systematically exploring the operating parameter space of the VFD established slicing of ca. 200 μm long purified BNNTs down to 340 nm to 400 nm, in ca. 53% yield, in a 1 : 1 mixture of IPA and water, in the absence of reagents/harsh chemicals, at a flow rate of 0.45 mL min-1, a concentration of 0.1 mg mL-1 BNNTs and an 8.5k rpm rotational speed, with the pulsed laser operating at 1064 nm and 250 mJ per pulse.
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