Universalized and robust length separation of carbon and boron nitride nanotubes with improved polymer depletion-based fractionation.

Partitioning nanoparticles by shape and dimension is paramount for advancing nanomaterial standardization, fundamental colloidal investigations, and technologies such as biosensing and digital electronics. Length-separation methods for single-walled carbon nanotubes (SWCNTs) have historically incurred trade-offs in precision and mass throughput, and boron nitride nanotubes (BNNTs) are a rapidly emerging material analogue. We extend and detail a polymer precipitation-based method to fractionate populations of either nanotube type at significant mass scale for four distinct nanotube sources of increasing average diameter (0.

Dispersant Effects on Single-Walled Carbon Nanotube Antibacterial Activity.

There is significant interest in understanding whether nanomaterials with outstanding mechanical or electrical properties also possess antibacterial properties. However, assessment of antibacterial activity is a complex problem at the interface of chemistry and microbiology. Results can be affected by many factors including nanomaterial size, surface chemistry, concentration, and the dispersion media.

Chiral Structure Formation during Casting of Cellulose Nanocrystalline Films.

A Landau-de Gennes formulation coupled with a mass-transfer equation was used to track the evaporation front and the development of chiral microstructures during the casting of sulfuric acid-hydrolyzed cellulose nanocrystal (CNC) films. These simulations are compared to thin-film casting experiments that used analogous processing parameters and environments. The results show that the initial concentration, chiral strength, surface anchoring, speed of drying, and the influence of initial shear alignment all affect the uniformity of the microstructure and the orientation of the chiral director.

Comparison of Attachment and Antibacterial Activity of Covalent and Noncovalent Lysozyme-Functionalized Single-Walled Carbon Nanotubes.

Carbon nanotube-lysozyme (LSZ) conjugates provide an attractive combination of high strength and antimicrobial activity. However, there has not been a direct comparison of the covalent and noncovalent methods for creating them. In this work, single-walled carbon nanotubes (SWNT) were functionalized with LSZ using both noncovalent adsorption and covalent attachment via -ethyl--(3-dimethylamino-propyl) carbodiimide hydrochloride--hydroxysuccinimide (EDC-NHS) chemistry.