Contact charging

Mica unmodified Hydrophilic and negatively charged Contact angle <10°b... 

Mica unmodified Hydrophilic and negatively charged Contact angle <10ob A 3l-40 No growth observed Losic et al. (2006) Yang et al. (2007)... 

The solution to the dilemma just posed can be found by comparing an electrolytic solution with a metallic conductor. In a metallic conductor, there is a lattice of positive ions that hold their equilibrium positions during the conduction process. In addition, there are the free conduction electrons which assume responsibility for the transport of charge. Contact is made to and from the metallic conductor by means of other metallic conductors [Fig. 4.48(a)]. Hence, electrons act as charge carriers throughout the entire circuit. 

The physicochemical aspects of micro- and macroemulsions have been discussed in relation to enhanced oil recovery processes. The interfacial parameters (e.g. interfacial tension, interfacial viscosity, interfacial charge, contact angle, etc.) responsible for enhanced oil recovery by chemical flooding are described. In oil/brine/surfactant/alcohol systems, a middle phase microemulsion in equilibrium with excess oil and brine forms in a narrow salinity range. The salinity at which equal volumes of brine and oil are solubilized in the middel phase microemulsion is termed as the optimal salinity. The optimal salinity of the system can be shifted to a desired value hy varying the concentration and structure of alcohol. 

The distinctive features of Warneck s photoionization technique are the pressure range covered (up to 0.2 Torr) and the direct measurement of ion residence times. The capability of working at high pressures makes possible the study of reactions with low rates, even termolecular association reactions. The residence time may be varied considerably and well-defined ion temperatures and drift velocities established at the higher pressures. The direct measurement of residence time eliminates certain errors which can occur in the calculation of this quantity—e.g., the electric field may be affected to an unknown extent by surface charges, space charge, contact potentials, and electric field penetration. The rate constant is directly determined from measured values of the ion residence time and of the initial and final concentrations of reactants or of products or of both. 

Physical characterizations of nanocellulose include particle size analysis, surface charge, contact angle, etc. Particle size analysis of nanocellulose can be done using dynamic light scattering (DLS) and surface charge, which can be measure by zeta potential [130]. 

---