Homogeneous Kinetics Research Articles

The kinetics of the formation of a solid solution in an Ag–Pd polycrystalline film system

The kinetics of homogenization of an Ag–Pd film system with a total thickness of 120 nm and a grain size of 5–10 nm has been studied by means of in situ TEM heating. The film system has been formed by the sequential deposition of components in a vacuum on the substrate at room temperature. It has been shown that diffusion processes are activated, starting from the temperature 453 K, resulting in complete homogenization of the film system at 573 K with preservation of its fine-grained structure. The effective diffusion coefficient in the Ag–Pd system was measured as 10−17–10−18 m2/s at 553 K. A possible mechanism of homogenization is discussed.

Special Issue on Radiation Chemistry: In Memory of K. D. Asmus

Special Issue on Radiation Chemistry: In Memory of K. D. Asmus

Microstructural Evolution of Aluminum Alloy 2618 During Homogenization and Its Kinetic Analysis

AbstractThe microstructure evolution of aluminum alloy 2618 and its homogenization kinetics were investigated by optical microscope, scanning electron microscope, energy dispersive spectroscopy and differential scanning calorimeter. The results show that the main constituent phases in as-cast alloy 2618 are α–Al, Al9FeNi phase and non-equilibrium binary θ (Al2Cu) phase instead of typical S (Al2CuMg) phase. The θ phase was dissolved into α–Al gradually and the continuous dendritic-network structure was broken with the increase of homogenization temperature and time. DSC analysis shows that the overburnt and liquidus temperatures of as-cast alloy 2618 are 506.4 °C and 638.0 °C, respectively. After the alloy was homogenized at optimized temperature 500 °C for 16 h, the θ phase was completely dissolved in matrix. The size and morphology of Al9FeNi phase had little change, while the liquidus temperature shifted to 641 °C. The calculated homogenization time for alloy 2618 at 500 °C is 15 h, which is in accordance with that obtained in homogenization experiments.

Fragility and molar volumes of non-stoichiometric chalcogenides: The crucial role of melt/glass homogenization

Melt-fragility index (m) and glass molar volumes (Vm) of binary Ge–Se melts/glasses are found to change reproducibly as they are homogenized. Variance of Vm decreases as glasses homogenize, and the mean value of Vm increases to saturate at values characteristic of homogeneous glasses. Variance in fragility index of melts also decreases as they are homogenized, and the mean value of m decreases to acquire values characteristic of homogeneous melts. Broad consequences of these observations on physical behavior of chalcogenides melts/glasses are commented upon. The intrinsically slow kinetics of melt homogenization derives from high viscosity of select super-strong melt compositions in the intermediate phase that serve to bottleneck atomic diffusion at high temperatures. Schematic of a near homogeneous GexSe100−x melt composed of homogeneous (dark) regions separated by heterogeneous (light) interfacial ones.

Mathematical model of chemical oscillations arising in a homogeneous system of cysteine and oxygenated complexes of iron(II)

A mathematical model of the homogeneous oxidation kinetics of cysteine in the presence of oxygenated complexes of iron(II) with dimethylglyoxime and cytosine expressed in the form of a system of three nonlinear differential equations is analyzed. The model is simplified by stoichiometric analysis of the suggested kinetic scheme. As determined on the basis of qualitative analysis of the system of differential equations, a single stationary state with the singular point assigned to the focus—spatial saddle type, from which a bifurcation of the Andronov-Hopf type can occur, is implemented. Upon solving numerically the system of differential equations for different initial conditions, it is found that the mathematical model has a solution in the form of a limit cycle, and the process runs in an oscillatory mode at such initial concentrations of the catalyst and cysteine that are comparable to their contents at which chemical oscillations are observed in experiments.

Thermokinetic Origin of Luminescent Traveling Fronts in the H2O2–NaOH–SCN––Cu2+ Homogeneous Oscillator: Experiments and Model

According to our original discovery, the oscillatory course of the Cu(2+)-catalyzed oxidation of thiocyanate ions with hydrogen peroxide, in nonstirred medium and upon the addition of luminol as an indicator, can be a source of a novel type of dissipative patterns--luminescent traveling waves. The formation of these fronts, contrary to the patterns associated with the Belousov-Zhabotinsky reaction, cannot be explained in terms of coupled homogeneous kinetics and diffusion, and under isothermal conditions. Both experimental studies and numerical simulations of the kinetic mechanism suggest that the spatial progress of these waves requires mainly the temperature gradient in the solution, which affects the local chemical reaction rate (and thus the oscillation period), with practically negligible contribution from diffusion of reagents. As a consequence of this thermokinetic coupling, the observed traveling patterns are thus essentially the phase (or kinematic) waves, formed due to the spatial phase shift of the oscillations caused by differences in chemical reaction rates. The temperature gradient, caused by the significant heat effect of exothermic oxidation of thiocyanate by hydrogen peroxide, can emerge spontaneously as a local fluctuation or can be forced externally, if the control of progress of the luminescent waves is to be achieved.

Features in chemical kinetics. II. A self-emerging definition of slow manifolds

In the preceding paper of this series (Part I [P. Nicolini and D. Frezzato, J. Chem. Phys. 138, 234101 (2013)]) we have unveiled some ubiquitous features encoded in the systems of polynomial differential equations normally applied in the description of homogeneous and isothermal chemical kinetics (mass-action law). Here we proceed by investigating a deeply related feature: the appearance of so-called slow manifolds (SMs) which are low-dimensional hyper-surfaces in the neighborhood of which the slow evolution of the reacting system occurs after an initial fast transient. Indeed a geometrical definition of SM, devoid of subjectivity, "naturally" follows in terms of a specific sub-dimensional domain embedded in the peculiar region of the concentrations phase-space that in Part I we termed as "attractiveness region." Numerical inspections on simple low-dimensional model cases are presented, including the benchmark case of Davis and Skodje [J. Chem. Phys. 111, 859 (1999)] and the preliminary analysis of a simplified model mechanism of hydrogen combustion.

Appropriate excitation wavelength removes obfuscations from pyrene excimer kinetics and mechanism studies

The experimental procedures of time-resolved laser photolysis studies of pyrene excimer formation in solution have been scrutinized and the appropriate modifications have been implemented. Contrary to the experimental methods applied in all related previous work, the selection of a suitable excitation wavelength (such that the corresponding pyrene absorbance is less than 0.5 absorbance units) utilized in our study results in simple homogeneous kinetics. Consequently, the rate parameters obtained and the mechanism proposed differ significantly from those published previously. The rate constant values of the unimolecular decay of the pyrene monomer, the unimolecular decay of the pyrene excimer, and the excimer formation in decane solution (η = 0.860 mPa s) at 25 °C are (2.38 ± 0.01) × 10(6) s(-1), (2.78 ± 0.02) × 10(7) s(-1), and (3.11 ± 0.06) × 10(9) M(-1) s(-1), respectively. The dissociation of the excimer to form a singlet excited state pyrene and a ground state pyrene was shown to be negligible. The energies of activation corresponding to the monomer and excimer unimolecular decays were found to be 2.51 ± 0.07 and 25.7 ± 0.7 kJ mol(-1), respectively. Also, our temperature resolved laser photolysis data revealed that the excimer formation has a negative energy of activation equal to -11.2 ± 0.5 kJ mol(-1). This unique phenomenon may be attributed to steric effects in the collision of the reactants. The current findings are important for the correct data analysis and interpretation in many applications of the pyrene excimer.

Phosphates (V) recovery from phosphorus mineral fertilizers industry wastewater by continuous struvite reaction crystallization process

Continuous DT MSMPR (Draft Tube Mixed Suspension Mixed Product Removal) crystallizer was provided with typical wastewater from phosphorus mineral fertilizers industry (pH < 4, 0.445 mass % of PO43−, inorganic impurities presence), dissolved substrates (magnesium and ammonium chlorides) and solution alkalising the environment of struvite MgNH4PO4·6H2O reaction crystallization process. Research ran in constant temperature 298 K assuming stoichiometric proportions of substrates or 20% excess of magnesium ions. Influence of pH (8.5–10) and mean residence time (900–3600 s) on product size distribution, its chemical composition, crystals shape, size–homogeneity and process kinetics was identified. Crystals of mean size ca. 25–37 μm and homogeneity CV 70–83% were produced. The largest crystals, of acceptable homogeneity, were produced using 20% excess of magnesium ions, pH 9 and mean residence time 3600 s. Under these conditions nucleation rate did not exceed 9 × 107 1/(s m3) according to SIG (Size Independent Growth) MSMPR kinetic model. Linear crystal growth rate was 4.27 × 10−9 m/s. Excess of magnesium ions influenced struvite reaction crystallization process yield advantageously. Concentration of phosphate(V) ions decreased from 0.445 to 9.2 × 10−4 mass %. This can be regarded as a very good process result. In product crystals, besides main component – struvite, all impurities from wastewater were detected analytically.

Determination of Heterogeneous Electron Transfer and Homogeneous Comproportionation Rate Constants of Tetracyanoquinodimethane Using Scanning Electrochemical Microscopy

We report the use of scanning electrochemical microscopy (SECM) in determining the heterogeneous electron transfer and homogeneous comproportionation kinetics of tetracyanoquinodimethane (TCNQ) in acetonitrile at Pt tip UMEs (radius 12.5–1 μm). TCNQ undergoes two consecutive one-electron reductions with comproportionation occurring between TCNQ2–, the product of the second reduction, and bulk TCNQ to produce TCNQ–. A standard rate constant, k(1)(0) = 2.9 ± 0.5 cm/s, for the first reduction was determined by tip voltammetry with total positive feedback and a large Pt substrate. A comparatively smaller rate constant, k(2)(0) = 0.44 ± 0.05 cm/s, for the second reduction was determined in the absence of comproportionation by tip voltammetry with the tip shielded from the bulk TCNQ solution by the TCNQ– diffusion layer of the large Pt substrate. A comproportionation rate constant, k(comp) = 1 × 10(6) M(–1) s(–1), was determined by tip pulse chronoamperometry at coaxially aligned tip and substrate UMEs of the same radius. Diffusion coefficients of the TCNQ species and standard potentials for the reductions were also determined. Experimental results were compared with 2D transient axisymmetric simulations and reported analytical equations.

New Directions in Advanced Modeling and in Situ Measurements Near Reacting Surfaces

Multidimensional numerical modeling and in situ spatially-resolved measurements of gas-phase thermoscalars over the catalyst boundary layer have fostered fundamental investigation of the heterogeneous and homogeneous chemical reaction pathways and their coupling at realistic operating conditions. The methodology for validating catalytic and gas-phase reaction mechanisms is firstly outlined for industrially-relevant fuels. Combination of advanced modeling and in situ near-wall species and velocity measurements is then used to address the intricate interplay between interphase fluid transport (laminar or turbulent) and hetero-/homogeneous kinetics. Controlling parameters of this interplay are the homogeneous ignition chemistry, flame propagation characteristics, competition between the catalytic and gaseous pathways for fuel consumption, diffusional imbalance of the limiting reactant, flow laminarization due to heat transfer from the hot catalytic walls, and fuel leakage through the gaseous reaction zone. Dynamic reactor operation and intrinsic flame dynamics driven by interactions between homogeneous kinetics and catalytic walls are outlined using detailed transient simulation. It is shown that the presence of catalytic reactions moderates flame instabilities. Future directions for transient modeling and for temporally-resolved in situ near-wall measurements are finally summarized.

Dual electrode micro-channel flow cell for redox titrations: Kinetics and analysis of homogeneous ascorbic acid oxidation

A channel flow cell, fabricated using microsterolithography (MSL), has been employed to determine the rate constant for the homogenous oxidation of ascorbic acid (AA) by an electrogenerated oxidant in aqueous solution under physiological pH conditions using a dual gold microband electrode format. Specifically, the oxidation of ferrocenylmethyl trimethyl-ammonium (FcTMA+) at an upstream electrode produce FcTMA2+, which oxidises AA in solution, yielding FcTMA+ which can undergo further heterogeneous oxidation at the upstream electrode. In addition, by setting the downstream electrode potential to a value where FcTMA2+ is detected at a transport-limited rate, collection efficiency measurements are also possible in a redox titration format. The benefits of studying homogeneous kinetics, and particularly this catalytic EC′ process, in a flow through system using a dual electrode format are highlighted. Collection efficiency measurements are shown to be particularly attractive for the detection of low levels of AA and are much more sensitive than measurements at a single electrode, particularly as a range of device parameters, such as flow rate, electrode size and electrode separation can be tuned to optimise detection. Various electrode sizes operating in the generation/collection (GC) mode have been assessed, with the optimum geometry of those studied (for the highest collection efficiency in the absence of homogenous reactions) being a small upstream generator electrode (25μM long), a large downstream collector electrode (400μM long), separated by a few tens of microns, in a channel of 200μm height and 4mm width. A full model for the cell hydrodynamics and mass transport has been developed using finite element modelling and extensive experiments are reported assessing the collection efficiency for different electrode geometries and AA concentrations. The homogeneous rate constant for the reaction between FcTMA2+ and AA is 5.5 (±1.6)×105M−1s−1.

Modeling the critical hydrogen concentration in the AECL test reactor

Hydrogen is added to a pressurized water reactor (PWR) to suppress radiolysis and maintain reducing conditions. The minimum hydrogen concentration needed to prevent radiolysis is referred to as the critical hydrogen concentration (CHC). The CHC was measured experimentally in the mid-1990s by Elliot and Stuart in a reactor loop at Atomic Energy of Canada (AECL), and was found to be approximately 0.5scc/kg for typical PWR conditions. This value is well below industry-normal PWR operating levels near 40scc/kg. Radiation chemistry models have also predicted a low CHC, even below the AECL experimental result. In the last few years some of the radiation chemical kinetic rate constants have been re-measured and G-values have been reassessed by Elliot and Bartels. These new data have been used in this work to revise the models and compare them with AECL experimental data. It is quite clear that the scavenging yields tabulated for high-LET radiolysis by Elliot and Bartels are not appropriate to use in the present context, where track-escape yields are needed to describe the homogeneous recombination kinetics in the mixed radiation field. In the absence of such data for high temperature PWR conditions, we have used the neutron G-values as fitting parameters. Even with this expedient, the model predicts at least a factor of two smaller CHC than was observed. We demonstrate that to recover the reported CHC result, the chemistry of ammonia impurity must be included.

Antioxidant activity coefficient, mechanism, and kinetics of different derivatives of flavones and flavanones towards superoxide radical

A systematic investigation of the electrochemically generated superoxide radical (O&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;●&amp;ndash;&lt;/sup&gt;) has been conducted in the presence of some flavonoids. Cyclic voltammetry was used to generate O&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;●&amp;ndash;&lt;/sup&gt; by reducing the molecular oxygen in DMSO at room temperature. The scavenging of the radical was monitored by the decrease in anodic or/and cathodic currents while linearly increasing the concentration of the flavonoid. The strength of interaction was quantified in terms of the binding constant (K&lt;sub&gt;b&lt;/sub&gt;)values ranging from 1 &amp;times; 10&lt;sup&gt;2&lt;/sup&gt; and 5 &amp;times; 10&lt;sup&gt;3&lt;/sup&gt;M&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;. The antioxidant activity coefficient (K&lt;sub&gt;ao&lt;/sub&gt;) was calculated from the linear part of the plot of &amp;lsquo;current decrease vs. flavonoid concentration&amp;rsquo;. Radical scavenging mechanism of the antioxidant was proposed and discussed in terms of the structure activity relationship. Nicholson-Shain method was employed to estimate the bimolecular homogeneous kinetics and on this basis control use of antioxidant is pointed out. &amp;nbsp;

Generalization of the Analytical Exponential Model for Homogeneous Reactor Kinetics Equations

Mathematical form for two energy groups of three‐dimensional homogeneous reactor kinetics equations and average one group of the precursor concentration of delayed neutrons is presented. This mathematical form is called “two energy groups of the point kinetics equations.” We rewrite two energy groups of the point kinetics equations in the matrix form. Generalization of the analytical exponential model (GAEM) is developed for solving two energy groups of the point kinetics equations. The GAEM is based on the eigenvalues and the corresponding eigenvectors of the coefficient matrix. The eigenvalues of the coefficient matrix are calculated numerically using visual FORTRAN code, based on Laguerre’s method, to calculate the roots of an algebraic equation with real coefficients. The eigenvectors of the coefficient matrix are calculated analytically. The results of the GAEM are compared with the traditional methods. These comparisons substantiate the accuracy of the results of the GAEM. In addition, the GAEM is faster than the traditional methods.

Continuous Reaction Crystallization of Struvite from Diluted Aqueous Solutions of Phosphate (V) Ions in DT MSMPR Crystallizer

Experimental work concerning continuous reaction crystallization of struvite MgNH4PO4.6H2O from diluted aqueous solutions of phosphates(V) (1.0 mass % of PO4) is presented. Laboratory tests were carried out in a DT MSMPR type crystallizer in 298K assuming stoichiometric ratio of the reagents. Influence of pH (8.5 – 10) and mean residence time of suspension in a crystallizer (900 – 3600 s) on product crystal size distribution, their size homogeneity and process kinetics was identified. Struvite crystals of mean size from ca. 23 to ca. 86 m, of diverse homogeneity (CV 62 – 90%) were produced. The largest crystal sizes of acceptable homogeneity corresponded to pH 8.5 and mean residence time elongated up to 3600 s. Under these conditions struvite nucleation rate did not exceed 2.9 107 1/(s m3) according to SIG MSMPR kinetic model. Linear growth rate of struvite crystals within the parameter ranges tested varied from 4.33 10–9 to 1.75 10–8 m/s.

On the spur lifetime and its temperature dependence in the low linear energy transfer radiolysis of water

In the spirit of the radiation chemical "spur model", the lifetime of a spur (τ(s)) is an important indicator of overlapping spurs and the establishment of homogeneity in the distribution of reactive species created by the action of low linear energy transfer (LET) radiation (such as fast electrons or γ irradiation). In fact, τ(s) gives the time required for the changeover from nonhomogeneous spur kinetics to homogeneous kinetics in the bulk solution, thus defining the so-called primary (or "escape") radical and molecular yields of radiolysis, which are obviously basic to the quantitative understanding of any irradiated chemical system. In this work, τ(s) and its temperature dependence have been determined for the low-LET radiolysis of deaerated 0.4 M aqueous solutions of H(2)SO(4) and pure liquid water up to 350 °C using a simple model of energy deposition initially in spurs, followed by random diffusion of the species of the spur during track expansion until spur overlap is complete. Unlike our previous τ(s) calculations, based on irradiated Fricke dosimeter simulations, the current model is free from any effects due to the presence of oxygen or the use of scavengers. In acidic solutions, the spur lifetime values thus obtained are in very good agreement with our previous calculations (after making appropriate corrections, however, to account for the possibility of competition between oxygen and Fe(2+) ions for H˙ atoms in the Fricke dosimeter, an effect which was not included in our original simulations). In this way, we confirm the validity of our previous approach. As expected, in the case of pure, oxygen-free water, our calculated times required to reach complete spur overlap are essentially the same (within uncertainty limits) as those found in acidic solutions. This explicitly reflects the fact that the diffusion coefficients for the hydrated electron and the H˙ atom that are involved in the overall calculation of the lifetime of spurs in neutral or acidic media, respectively, are of similar magnitude over the 25-350 °C temperature range studied.

The Impact of Melt-Conditioned Twin-Roll Casting on the Downstream Processing of an AZ31 Magnesium Alloy

Melt conditioning by intensive shear was used prior to twin-roll casting of AZ31 magnesium alloy strip to promote heterogeneous nucleation and to provide a refined and uniform microstructure without severe macrosegregation. The cast strip was then processed by homogenization, hot rolling, and annealing, and its downstream processing was compared with a similar cast strip produced without melt conditioning. Melt conditioning produced strip with accelerated kinetics of recrystallization during homogenization and improved performance in hot rolling and improved tensile properties. An average tensile elongation of ~28 pct was achieved, which is substantially higher than the ~9 pct obtained for the strip produced without melt conditioning which is consistent with reported values (~6 pct to 16 pct). The as-cast, homogenized, and hot-rolled microstructures of the strip were characterized. The kinetics of homogenization and hot-rolling process have been discussed in detail.

Mathematical Modeling and Comparisons of Relapse Patterns in AML with 11q23/MLL translocations and Normal Karyotype AML with MLL-PTD

Abstract 750▪FN2▪This icon denotes a clinically relevant abstract INTRODUCTION:Close monitoring of minimal residual disease (MRD) in acute myeloid leukemia (AML) patients in complete remission (CR) holds the promise of detecting relapses in time to initiate cytoreduction prior to a full-blown hematological relapse. However, to implement MRD measurements in protocols as well as clinical practice, key parameters such as optimal sampling intervals and sampling tissues (peripheral blood (PB) vs. bone marrow (BM)) are necessary. We have previously defined these for PML-RARA+, CBFB-MYH11+, RUNX1-RUNX1T1+, NPM1 mutated AML and for AML with over-expression of the WT1 gene (Ommen, et al, BLOOD, 2010). However, the important subgroups with 1) rearrangement of the MLL gene 11q23 translocations (t(11q23)) and 2) partial tandem duplication of the MLL-gene (MLL-PTD) have not been studied, yet. AIM: Optimal sampling intervals and relapse detection rates were investigated in the two AML subgroups with t(11q23) and MLL-PTD. Median time from MRD positivity to hematological relapse should be defined. PATIENTS AND METHODS: 1,321 MRD samples from 258 patients were available for analysis. Based on CR samples from patients who did not experience a relapse we initially established a cut-off level for MRD conversion above which hematological relapse was inevitable (MLL-PTD: 45 patients, 150 samples and t(11q23): 55 patients, 212 samples). Based on MRD courses from 21 pts with MLL-PTD experiencing 24 relapses (CR samples: n=149) and 16 pts with t(11q23) with 17 relapses (CR samples: n=100) we analyzed relapse kinetics using the model we have previously published (Ommen, et al, BJH 2008). This model exploits the information from both positive and negative samples taken prior to relapse. The model establishes the relationship between sampling intervals and the likelihood of discovering a patient positive prior to hematological relapse on the one hand, and the median time from first positive sample to hematological relapse (HR) on the other. RESULTS: We observed strikingly different relapse kinetic patterns in the AML subgroups studied here. Thus, MLL-PTD levels were found to be very informative in some cases with conversion to MRD positivity occurring up to 10 months prior to HR (conversion 4–10 months before relapse in 5/24 relapses, but only 45% (5/11) of patients where bone marrow status could be evaluated 2 month before HR were qPCR positive. Based on this data a 3-monthly BM sampling schedule yield only mediocre relapse detection rates (60%) but in the cases where a positive sample is obtained, relative long time passes before hematological relapse occurs (2 months). Conversely, in the cases with the different t(11q23) markers (t(9;11): n=7, t(6;11): n=5, t(10;11): n=2 and t(11;19): n=2) relapses were correlated with very homogenous relapse kinetics. None of the t(11q23) relapses could be detected 3 months before HR. On the other hand, 80% (4/5) of relapses had converted to negativity as assed by quantitative 2 months before HR. This translated into a 3-monthly BM sampling schedule yielding relapse detection rates of 75% with a median time to HR of 1.1 months. Compared to the relapse kinetics of previously published AML subtypes, the in vivo growth of t(11q23) leukemic cells (leukemic clone median doubling time 9 days, range 4.5–15 days) is faster than both the in vivo growth of CBFB-MYH11 relapses (doubling time 36 days, range 7.4–175 days) (P<0.01) and NPM1c+FLT3-ITD- relapses (doubling time 15 days, range 2.2–33 days) (P=0.07) (Ommen, et al, Blood 2010). CONCLUSION: These data add considerably to our knowledge of molecular relapse kinetics in AML by adding t(11q23) cases and those with MLL-PTD to those already described in the literature. They can be utilized for statistical power calculations when designing clinical trials and allow for cost-benefit calculations regarding MRD monitoring implementation in clinical decision-making in the individual patient. Disclosures:Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Alpermann:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Study of an ultrasound‐based process analytical tool for homogenization of nanoparticulate pharmaceutical vehicles

There are currently no adequate process analyzers for nanoparticulate viscosity enhancers. This article aims to evaluate ultrasonic resonator technology as a monitoring tool for homogenization of nanoparticulate gels. Aqueous dispersions of colloidal microcrystalline cellulose (MCC) and a mixture of clay particles with xanthan gum were compared with colloidal silicon dioxide in oil. The processing was conducted using a laboratory-scale homogenizing vessel. The study investigated first the homogenization kinetics of the different systems to focus then on process factors in the case of colloidal MCC. Moreover, rheological properties were analyzed offline to assess the structure of the resulting gels. Results showed the suitability of ultrasound velocimetry to monitor the homogenization process. The obtained data were fitted using a novel heuristic model. It was possible to identify characteristic homogenization times for each formulation. The subsequent study of the process factors demonstrated that ultrasonic process analysis was equally sensitive as offline rheological measurements in detecting subtle manufacturing changes. It can be concluded that the ultrasonic method was able to successfully assess homogenization of nanoparticulate viscosity enhancers. This novel technique can become a vital tool for development and production of pharmaceutical suspensions in the future.