Diameter of Carbon Nanotube-Directed Self-Assembly of Amphiphilic Block Copolymers
AbstractThe cooperative self-assembly of nanoparticles and amphiphilic block copolymers has attracted increasing interests as it offers effective routes to achieve nanocomposite supramolecular structures with desired structure and properties. The incorporation of nanoparticles usually tunes the self-assembly structure of block copolymers, as the copolymer–nanoparticle interactions may change the relative volume ratio of hydrophobic block/hydrophilic block copolymers. It should be noted that the micro-size length and the strong nonpolar feature of carbon nanotubes (CNTs) may cause the block copolymer–CNT interactions to differ from the the block copolymer–nanoparticle interactions. Herein, we show that the diameter of CNTs and the copolymer/CNT ratio have a profound effect on the self-assembly behavior of amphiphilic block copolymers. Upon the addition of carboxylated multi-walled carbon nanotubes (c-MWCNTs, diameter <8 nm,) to the methoxy polyethylene glycol-poly (D,L-lactic acid) (MPEG-PDLLA) solution, it is difficult to observe the c-MWCNTs directly in TEM images. However, it has been found that they form supramolecular nanocomposite structures with MPEG-PDLLA. Moreover, these supramolecular structures transform from core–shell spherical micelles into rod-like micelles and then into large composite aggregates with the increase of the c-MWCNT addition. However, in the case of the addition of c-MWCNTs with a diameter of 30–50 nm, the dispersed c-MWCNTs and spherical core–shell micelles could be observed simultaneously in the TEM images at a low c-MWCNT addition, and then the micelle structure disappeared and only well-dispersed c-MWNTs were observed in TEM images at a high c-MWCNT addition. A possible model was proposed to explain the rule of CNTs participating in the formation of copolymer/CNT nanocomposite structures. It was also shown that as-prepared copolymer/CNT supramolecular nanocomposites could be used as drug carriers, enabling the adjustment of the drug loading and release time. View Full-Text
Share & Cite This Article
Wang, Z.; Tao, S.; Chu, Y.; Xu, X.; Tan, Q. Diameter of Carbon Nanotube-Directed Self-Assembly of Amphiphilic Block Copolymers. Materials 2019, 12, 1606.
Wang Z, Tao S, Chu Y, Xu X, Tan Q. Diameter of Carbon Nanotube-Directed Self-Assembly of Amphiphilic Block Copolymers. Materials. 2019; 12(10):1606.Chicago/Turabian Style
Wang, Zihao; Tao, Susu; Chu, Yanyan; Xu, Xiaoyan; Tan, Qinggang. 2019. "Diameter of Carbon Nanotube-Directed Self-Assembly of Amphiphilic Block Copolymers." Materials 12, no. 10: 1606.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.