The Vogel–Fulcher–Tammann equation, also known as Vogel–Fulcher–Tammann–Hesse equation or Vogel–Fulcher equation (abbreviated: VFT equation), is used to describe the viscosity of liquids as a function of temperature, and especially its strongly temperature dependent variation in the supercooled regime, upon approaching the glass ...

Vogel -Fulcher -Tammann方程，也称为Vogel -Fulcher -Tammann -Hesse方程或Vogel -Fulcher方程（缩写：VFT方程），用于描述液体的粘度，尤其是其温度的函数，尤其是其强度接近玻璃过渡后，超冷...

2013年7月1日 · The VFT expression of the viscosity is given by (1) η = η 0 exp B VFT T − T 0, where T is the absolute temperature, η 0 is the value of the viscosity at the high temperature limit, and B VFT is a quantity related with the activation barrier.

2023年1月15日 · The prepared fabric exhibited excellent flame retardancy with a limiting oxygen index value (LOI) of 42.0 % and a damaged length of less than 40 mm in the vertical flammability test (VFT). Besides, the cotton-PEI/APP-TMC sample was not ignited in the 50 kW/m 2 cone calorimeter test with a dramatic decrease in both the peak heat release rate and ...

AMP-SiO 2 -KH570@COT shows the best flame retardancy with the highest char residue rate (48.7%) (6.5 times that of raw cotton fabric), and a LOI value of 27.7% (non-flammable level). It can self-extinguish with a char length of only 8.2 cm in a VFT.

2024年10月13日 · VFT and LOI tests were effective methods for assessing flame resistance. Generally, a higher LOI value and a shorter charcoal frame length indicate lower flammability of the fabric and vice versa (Zhi et al. 2022). Figure 7 and Fig. 8a show the images and char length of samples after VFT.

L'équation de Vogel-Fulcher-Tammann, ou plus succinctement loi de Vogel-Fulcher, est une loi empirique utilisée dans la modélisation de différents problèmes physiques : viscosité d'un matériau au voisinage d'une transition vitreuse, relaxation diélectrique des matériaux relaxeurs, dynamique des verres de spins, etc. Elle prend la forme ...

2022年4月25日 · The flame retardancy of uncoated and coated polyester fabrics was characterized by the vertical flammability test (VFT) and limiting oxygen index (LOI) test.

2019年8月27日 · The so-called Vogel-Fulcher-Tamman (VFT) relation has been extensively used to parameterize the relaxation dynamics in RF, although no microscopic description has been firmly...

VFT law is the increase of the range of elas-tic interaction between local relaxation events. In this theory, we also discuss the origin of cooperativity of re-laxation, the absence of divergence of �. d by elemen-tary local structural rearrangements, during whic.