It is becoming common practice to partition glass-forming liquids into two classes based on the dependence of the shear viscosity η on temperature T . In an Arrhenius plot, ln η vs 1/ T , a strong liquid shows linear behavior whereas a fragile liquid exhibits an upward curvature [super-Arrhenius (SA) behavior], a situation customarily described by using the Vogel–Fulcher–Tammann law. Here we analyze existing data of the transport coefficients of 84 glass-forming liquids. We show the data are consistent, on decreasing temperature, with the onset of a well-defined dynamical crossover η _× , where η _× has the same value, η _× ≈ 10 ³ Poise, for all 84 liquids. The crossover temperature, T _× , located well above the calorimetric glass transition temperature T _g , marks significant variations in the system thermodynamics, evidenced by the change of the SA-like T dependence above T _× to Arrhenius behavior below T _× . We also show that below T _× the familiar Stokes–Einstein relation D / T ∼ η ^-1 breaks down and is replaced by a fractional form D / T ∼ η ^{- ζ} , with ζ ≈ 0.85.

Functionalized chitosan–silica hybrid materials were synthesized, characterized and used for adsorption of rare-earth ions. These adsorbents can be used for the separation of mixtures of rare-earths.

Using NMR, we measure the proton chemical shift δ, of supercooled nanoconfined water in the temperature range 195 K < T < 350 K. Because δ is directly connected to the magnetic shielding tensor, we discuss the data in terms of the local hydrogen bond geometry and order. We argue that the derivative −(∂ ln δ/∂ T ) _P should behave roughly as the constant pressure specific heat C _P ( T ), and we confirm this argument by detailed comparisons with literature values of C _P ( T ) in the range 290–370 K. We find that −(∂ ln δ/∂ T ) _P displays a pronounced maximum upon crossing the locus of maximum correlation length at ≈240 K, consistent with the liquid-liquid critical point hypothesis for water, which predicts that C _P ( T ) displays a maximum on crossing the Widom line.