دانلود رایگان ترجمه مقاله همبستگی فولرین های BnNn (نشریه الزویر ۲۰۱۲)

بهم آمیختگی فولرین های BnNn: مسیر جدیدی برای تولید نانولوله های نیترید بور با قطر کوچک

Coalescence of BnNn fullerenes: A new pathway to produce boron nitride nanotubes with small diameter

۱ Introduction

After its successful experimental realization [1], carbon nanotubes (CNTs) have stimulated tremendous interest in the extraordinary properties of nanotubular structures [2]. Recently, boron nitride nanotubes (BNNTs), which are structurally similar to CNTs, have attracted increasing attention [3–۸]. BNNTs were theoretically predicted [9] in 1994 and successfully synthesized in 1995 [10]. Compared with metallic or semiconducting CNTs, BNNTs are all stable wide band gap semiconductors independent of their helicity and diameter, regardless of whether the nanotube is single-walled or multi-walled [8]. In addition, BNNTs possess high chemical stability, excellent mechanical properties, and high thermal conductivity [5]. Thus, BNNTs are expected to be a promising nanomaterial in a variety of potential fields such as nano-devices, functional composites, and electrically insulating substrates [5,11].

Nowadays, research on CNTs has become popular because many laboratories are capable of producing their own samples for various investigations. However, the progress of BNNT research is still limited by the availability of BNNT samples for widespread investigation of their properties and applications. The techniques known for BNNT growth, for example, arc-discharge [10], laser vaporization [12], BN substitution method from CNT templates [13], chemical vapor deposition (CVD) [14], and high-temperature ball milling [15], involve either specific instrumentation, high growth temperatures (>1300◦C), and/or dangerous chemistry. Recently, despite the low-temperature synthesis of BNNTs, such as plasma-enhanced pulsed-laser deposition (PE-PLD) [16], high-quality BNNT samples still remained difficult to produce. Furthermore, growing highly pure single-walled BNNTs remains a challenge, especially for small diameter BNNTs [7]. To date, a number of theoretical works have predicted the existence of BNNTs with small diameters (e.g., see Ref. [9]) and possibly possessing semiconducting properties with direct or indirect band gaps. However, there are few experimental reports on the synthesis of this kind of BNNT; only the zigzag (6, 0) BNNT with a small diameter of 5 Å has been reported [17]. This hinders new understanding of the properties of BNNTs and the promotion of research in the field.