A Superior Two-Dimensional Phosphorus Flame Retardant: Few-Layer Black Phosphorus
Taiming Zhang,
Huanyu Xie,
Shuai Xie,
Ajuan Hu,
Jie Liu,
Jian Kang,
Jie Hou,
Qing Hao,
Hong Liu,
Hengxing Ji
Affiliations
Taiming Zhang
State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, 2# Sipailou, Nanjing 210096, China
Huanyu Xie
Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230026, China
Shuai Xie
Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230026, China
Ajuan Hu
Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230026, China
Jie Liu
Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230026, China
Jian Kang
Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230026, China
Jie Hou
School of Resource Environment and Safety Engineering, University of South China, Hengyang 421001, China
Qing Hao
State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, 2# Sipailou, Nanjing 210096, China
Hong Liu
State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, 2# Sipailou, Nanjing 210096, China
Hengxing Ji
Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230026, China
The usage of flame retardants in flammable polymers has been an effective way to protect both lives and material goods from accidental fires. Phosphorus flame retardants have the potential to be follow-on flame retardants after halogenated variants, because of their low toxicity, high efficiency and compatibility. Recently, the emerging allotrope of phosphorus, two-dimensional black phosphorus, as a flame retardant has been developed. To further understand its performance in flame-retardant efficiency among phosphorus flame retardants, in this work, we built model materials to compare the flame-retardant performances of few-layer black phosphorus, red phosphorus nanoparticles, and triphenyl phosphate as flame-retardant additives in cellulose and polyacrylonitrile. Aside from the superior flame retardancy in polyacrylonitrile, few-layer black phosphorus in cellulose showed the superior flame-retardant efficiency in self-extinguishing, ~1.8 and ~4.4 times that of red phosphorus nanoparticles and triphenyl phosphate with similar lateral size and mass load (2.5~4.8 wt%), respectively. The char layer in cellulose coated with the few-layer black phosphorus after combustion was more continuous and smoother than that with red phosphorus nanoparticles, triphenyl phosphate and blank, and the amount of residues of cellulose coated with the few-layer black phosphorus in thermogravimetric analysis were 10 wt%, 14 wt% and 14 wt% more than that with red phosphorus nanoparticles, triphenyl phosphate and blank, respectively. In addition, although exothermic reactions, the combustion enthalpy changes in the few-layer black phosphorus (−127.1 kJ mol−1) are one third of that of red phosphorus nanoparticles (−381.3 kJ mol−1). Based on a joint thermodynamic, spectroscopic, and microscopic analysis, the superior flame retardancy of the few-layer black phosphorus was attributed to superior combustion reaction suppression from the two-dimensional structure and thermal nature of the few-layer black phosphorus.
