TY - JOUR
T1 - Novel ionic liquid crystals based on N-alkylcaprolactam as cations
AU - Yang, Jing
AU - Zhang, Qinghua
AU - Zhu, Laiying
AU - Zhang, Shiguo
AU - Li, Jian
AU - Zhang, Xiaoping
AU - Deng, Youquan
PY - 2007/5/15
Y1 - 2007/5/15
N2 - A novel series of ionic liquids (ILs) based on N-alkyl-ε-caprolactam as cations [Cn-CP]+ (Cn = alkyl with different numbers of C atoms; n -6, 8, 10, 12, 16, or 18) containing toluene-p-sulfonate [TS]- and methanesulfonate [MS]- as anions have been synthesized via a one-step atom-economic reaction. Characterizations of these ILs by differential scanning calorimetry, polarizing optical microscopy, variabletemperature powder X-ray diffraction, etc., were conducted. The results showed that the caprolactambased ILs (n ≥ 8) were enantiotropic thermotropic liquid crystals, except for C18-CPMS (monotropic), and displayed smectic A phases. Some properties, such as higher transition enthalpies (e.g., ΔH = 83.1 kJ/mol for C18-CPTS), higher specific heat capacities (e.g., Cp = 2.85 J/g·K for C16-CPTS) and higher heat storage densities (e.g., sensible heat storage density Es = 262.81 MJ/m3 for C16~CPTS; latent heat storage density E1 -146.0 MJ/m3 for C18-CRTS), were observed. Fluorescence measurements showed that the homologous Cn-CPTS ILs exhibited strong fluorescence behavior. Finally, the test of acute toxicity toward rats showed that these new ILs were less toxic than the popular [BMIm]BF4 IL.
AB - A novel series of ionic liquids (ILs) based on N-alkyl-ε-caprolactam as cations [Cn-CP]+ (Cn = alkyl with different numbers of C atoms; n -6, 8, 10, 12, 16, or 18) containing toluene-p-sulfonate [TS]- and methanesulfonate [MS]- as anions have been synthesized via a one-step atom-economic reaction. Characterizations of these ILs by differential scanning calorimetry, polarizing optical microscopy, variabletemperature powder X-ray diffraction, etc., were conducted. The results showed that the caprolactambased ILs (n ≥ 8) were enantiotropic thermotropic liquid crystals, except for C18-CPMS (monotropic), and displayed smectic A phases. Some properties, such as higher transition enthalpies (e.g., ΔH = 83.1 kJ/mol for C18-CPTS), higher specific heat capacities (e.g., Cp = 2.85 J/g·K for C16-CPTS) and higher heat storage densities (e.g., sensible heat storage density Es = 262.81 MJ/m3 for C16~CPTS; latent heat storage density E1 -146.0 MJ/m3 for C18-CRTS), were observed. Fluorescence measurements showed that the homologous Cn-CPTS ILs exhibited strong fluorescence behavior. Finally, the test of acute toxicity toward rats showed that these new ILs were less toxic than the popular [BMIm]BF4 IL.
UR - http://www.scopus.com/inward/record.url?scp=34249713257&partnerID=8YFLogxK
U2 - 10.1021/cm062675s
DO - 10.1021/cm062675s
M3 - 文章
AN - SCOPUS:34249713257
SN - 0897-4756
VL - 19
SP - 2544
EP - 2550
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 10
ER -