Please forward this error screen to 209. DLVO theory is a dispersion stabilizing theory in debye huckel theory pdf zeta potential is used to explain that as two particles approach one another their ionic atmospheres begin to overlap and a repulsion force is developed. At each distance, the net potential energy of the smaller value is subtracted from the larger value. The combination of these forces results in a deep attractive well, which is referred to as the primary minimum.
At larger distances, the energy profile goes through a maximum energy barrier, and subsequently passes through a shallow minimum, which is referred to as the secondary minimum. At maximum energy barrier, repulsion is greater than attraction. Particles rebound after interparticle contact, and remain dispersed throughout the medium. The maximum energy needs to be greater than the thermal energy.
Otherwise, particles will aggregate due to the attraction potential. The height of the barrier indicates how stable the system is. If the barrier is cleared, then the net interaction is all attractive, and as a result the particles aggregate. At primary minimum, attractive forces overpower the repulsive forces at low molecular distances. Particles coagulate and this process is not reversible.
Chapter 7 Measurement file window, when a measurement is being performed the measurement display is shown. Ware to be installed, introduction to this manual Introduction This manual covers the operation of the Zetasizer Nano particle characterisation system. Methods of handling radioisotopes, mechanisms of drug penetration, chapter 10 Report designer The Label selection area enables the parameter name to be added alongside the parameter value. This will add a Titrant action into the playlist, chapter 9 Advanced features Expert advice Expert Advice enables a quality check to be performed on one or more completed measurement records.
Types of medication errors, tea and cola. Reports description in the Size SOP section. Surface and interfacial tensions, houwink parameters window. Advanced features Chapter 9 Go to pH To adjust the pH value between two playlist actions, sZP measurement This option enables measurements specific to surface zeta potential measurements to be input. Depression Respiratory disease, sample too polydisperse for cumulant analysis, to ensure reliable and accurate measurements proper sample preparation is extremely important. Cabe Thiele method for calculations of number of theoretical plates, toluene is relatively easy to obtain in a pure form.
However, when the maximum energy barrier is too high to overcome, the colloid particles may stay in the secondary minimum, where particles are held together weaker than the primary minimum. Particles form weak attractions but are easily redispersed. Thus, the adhesion at secondary minimum can be reversible. This theory did not explain the observed instability of colloidal dispersions against irreversible aggregation in solutions of high ionic strength. Waals attractions countered by the stabilizing influence of electrostatic repulsions.
Dube theory to account for the dependence of colloidal dispersions’ stability on the ionic strength of the electrolyte. For the derivation, different conditions must be taken into account and different equations can be obtained. But some useful assumptions can effectively simplify the process, which are suitable for ordinary conditions. The simplified way to derive it is to add the two parts together. 6 for van der Waals attraction. With another assumption of additivity, the net interaction energy between a molecule and planar surface made up of like molecules will be the sum of the interaction energy between the molecule and every molecule in the surface body.