Contrast Variation Small Angle Neutron Scattering Investigation of Micro- and Nano-Sized TATB.

Panqi Song,Liangfei Bai,Lili Qiu,Qiang Tian,Guangai Sun,Xiaoqing Tu,Guiyu Zeng,Jian Gong,Liang Chen

doi:10.3390/ma12162606

Abstract

Small angle neutron scattering (SANS) with contrast variation was used to characterize the fractal behavior and embedded porosity of micro/nano-sized 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) crystallites, gauging the effects of particle sizes on the microstructural features. Scattering results reveal that the external surface of micro-sized TATB crystallites are continuous and smooth interfaces and their internal pores display a surface fractal structure (surface fractal dimension 2.15 < DS < 2.25), while the external surface of nano-sized TATB particles exhibit a surface fractal structure (surface fractal dimension 2.36 < DS < 2.55) and their internal pores show a two-level volume fractal structure (large voids consist of small voids). The voids volume fraction of nano-sized TATB particles are found increased distinctively when compared with micro-sized TATB particles on length scale between 1 nm and 100 nm. Specific surface areas are also estimated based on Porod law method, which are coincident with Brunauer-Emmett-Teller (BET) measurements. The contrast variation technique distinguishes the information of internal voids from external surface, suggesting SANS is a powerful tool for determining the microstructural features, which can be used to establish the relationship between microstructures and properties of micro/nano-energetic materials.

Highlights

IntroductionMicro/nano-energetic materials, as a new type of functional materials, have attracted extensive attention due to their excellent performances, such as high energy releasing rate, exceptional combustion efficiency, tailored burning rate, increased shock sensitivity and reduced impact sensitivity [1,2,3]
Micro/nano-energetic materials, as a new type of functional materials, have attracted extensive attention due to their excellent performances, such as high energy releasing rate, exceptional combustion efficiency, tailored burning rate, increased shock sensitivity and reduced impact sensitivity [1,2,3].As widely reported, microstructures such as particle morphologies, sizes, and void size distributions have significant influence on these properties [3,4,5,6,7,8]
It has been reported that embedded submicron pores play an essential part in the formation of hot spots, and groups of small pores can just produce the same efficiency compared with a single large pore in generating a hot spot [9,10,11]

Summary

Introduction

Micro/nano-energetic materials, as a new type of functional materials, have attracted extensive attention due to their excellent performances, such as high energy releasing rate, exceptional combustion efficiency, tailored burning rate, increased shock sensitivity and reduced impact sensitivity [1,2,3]. Microstructures such as particle morphologies, sizes, and void size distributions have significant influence on these properties [3,4,5,6,7,8]. Precise characterization of the surface and void features via various types of apparatuses is essential for exploring the structure–property relationship of micro/nano-energetic materials

Methods

Results

Conclusion