Novel paint driers based on iron co-ordination complexes were investigated for use as stoving finishes in oil-based coatings. Cis 9, cis 12-octadecadienoic acid was employed as a model vehicle because of its high drying capacity. Iron compounds generally have low catalytic efficiency at low temperatures which however improve with rises in temperature. The catalytic efficiency of some iron compounds was compared with those of some conventional driers at room temperature; 60 C, 80 C and 1200 C. To make the results comparative, equal weights of drier (0.05%) metal were employed in one series of experiments. In another series, a much higher concentration (0.25%) metal based on the weight of 9,12-octadecadienoic acid was employed. Equal weights of drier combination(s) and variable drier weights were examined to determine synergism or antagonism in the autoxidative systems. Maximum oxygen absorption, changes in iodine and peroxide values were monitored to determine a comparative catalytic performance of the driers at the reaction temperatures used. The reactivity of iron co-ordination complexes was found to be influenced by the organic compound with which the iron is chelated. Zerovalent iron complexes can be employed as high temperature driers. For convenience some common names have been used for major chemicals of importance in this work, e. g., Linoleic acid; cis 9, cis 12-octadecadienoic acid. Ferrocene; dicyclopentadienyl iron.

In the modern automotive industry, more and more manufacturers recognise that vehicle paint appearance makes an important contribution to customer satisfaction. Attractive appearance has become one of the important factors for customers in making a decision to purchase a car. Objective measurement of the quality of autobody paint appearance, as perceived by the customer, in a repeatable, reproducible, continuous scale manner is an important requirement for improving the paint appearance. It can provide car manufacturers a standard reference to evaluate the quality of the paint appearance. This thesis mainly deals with the measurement of paint appearance quality in the automotive industry by investigating, identifying and developing measurement methods in this area. First of all, the 'state of the art' in the area of paint appearance measurement was presented, which summarised the concept of appearance, models, attributes and definitions. To further identify the parameters and instruments used in the automotive industry, a round robin test was launched to perform visual assessment and instrument measurements on a set of panels in some European car manufacturers. A summary of the correlation found between measurable parameters and visual assessment provided the basis of the further work. Based on the literature survey and round robin test results, the next work is mainly concentrated on the two most important parameters, 'orange peel' and 'metal texture effect', how to separate and evaluate them. Digital signal processing technique, FFT and Filtering, have been employed to separate them and a set of measures have been provided for evaluation. At the same time, the technique for texture pattern recognition was introduced to evaluate the texture effect when a fine texture comparison was needed. A set of computable textural parameters based on grey-tone spatial-dependence matrices gives good correlation directly corresponding to visual perception. To resolve the overall appearance modelling problem, two novel and more powerful modelling tools, artificial neural networks and fuzzy logic, are introduced to model the overall appearance. The test results showed that both of them are able to reflect the correlation between overall appearance and the major parameters measured from a painted surface. Finally, an integrated measurement system, 'Smart Appearance', was developed using the image processing techniques and the artificial neural network model. The implement results show that this system can measure the major attributes of paint appearance and provide an overall appearance index corresponding to human visual perception. This system is helpful to product quality control on car body paint. It also could be used on the paint production line for dynamic measurement.

Uma forma de reduzir a difusão de agentes agressivos para o interior do concreto é através da aplicação de sistemas de pintura, que funcionam como uma barreira ao ingresso destes agentes. A difusão dos agentes através de películas de pintura está relacionada com a sua porosidade, que, por sua vez, depende principalmente do teor e estrutura química da resina e do teor e morfologia dos pigmentos. Esta tese teve por objetivo principal demonstrar que, com uma formulação adequada, as tintas à base de resina acrílica podem ser utilizadas como barreira de proteção eficiente contra a penetração de água e vapor de água, anidrido carbônico (C\'O IND.2\') e íons cloreto, em estruturas de concreto ou em outros tipos de substratos. As formulações das tintas foram definidas em função do tipo de acabamento final e obtidas pela variação da relação pigmento/resina. Foram realizados ensaios de caracterização nas tintas líquidas e nas resinas utilizadas na preparação das tintas estudadas, bem como ensaios de desempenho nas películas livres e em concretos pintados, que apresentavam resistência à compressão de 20 e 40 Mpa. Para a medida da resistência à penetração dos agentes agressivos no concreto, foram desenvolvidos ensaios acelerados, com base em metodologias de avaliação de argamassas e concretos, adaptados a substratos pintados. A microestrutura das películas de tinta foi correlacionada com as propriedades físicas das películas e dos concretos pintados. Os resultados obtidos mostram a importância da formulação das tintas nos fenômenos de transporte e, além disso, mostram que tintas acrílicas e as estirenoacrílicas com diferentes temperaturas vítreas (Tg) apresentam comportamento físico distinto. Tintas de acabamento semi-brilho conferem boa proteção contra a penetração de agentes agressivos no concreto, enquanto que as de acabamento fosco apresentam função mais decorativa do que de proteção. / The diffusion of aggressive agents into concrete can be reduced by the application of painting systems which work as barriers to these agents. The capacity of these agents to pass through the paint is related to its porosity, which in turn is mainly dependent on the structure and content of the resin and on the morphology and content of the pigments. The main objective of this thesis is to demonstrate that with adequate formulation, paints based on acrylic resin polymers can be used as efficient barriers against the penetration of water and water vapour, carbon dioxide and chloride in concrete structures or any other porous substrate. Paint formulations were defined based on the final appearance (gloss) and obtained by varying the pigmentbinder ratio. Characterization tests on the liquid paints and polymers prepared for this study were done, as were performance tests on free dry films and painted concrete substrates, with compressive strength of 20 MPa and 40 MPa. In order to determine the effectiveness of paint in inhibiting the diffusion of aggressive agents into concrete, accelerated tests based on methodologies for the evaluation of mortars and concrete were developed. The films microstructures were correlated with their physical properties and with painted concrete. The results showed that the formulation of the paints has a important effect on the transport mechanism and also that acrylic and styrene-acrylic paints with different transition temperatures (Tg) do not present the same physical behavior. Glossy paints presented a high level of protection against the penetration of aggressive agents whereas matte finishes offered a more aesthetic function rather than protection.

Interior flat, white latex paint is a common coating applied to walls around the world. Development of a coating with one coat hide capability is a pinnacle achievement for paint formulators as it has the potential to save consumers both time and money. One coat paints already exist on the market, but they are limited in color, coverage, and often have many disclaimers. Work done was part of a project initiated by ChemoursTM Titanium Technologies. The goal of the project presented in this article was to create an interior flat, white latex paint that yields a spread rate of greater than 400 ft2/gal., which is advertised by many below critical pigment volume concentration (CPVC) commercial paints. In order to achieve this goal, an above CPVC paint with a high TiO2 content was created and continuously improved. Improvement of the formulation involved numerous experimental variations including adjustments to the hydroxyethylcellulose (HEC) molecular weight, dispersant chemistry, latex chemistry, TiO2 concentration, extender package, and rheology modifier type. The sheen value, relative light scattering, and spread rate were the main measurements conducted in order to judge formulation improvement. Complications with the spread rate procedure forced its adaptation in order to collect less variable data with the high density, shear thinning formulations. It was found that shorter opacity charts yielded more precise spread rate data than the longer opacity charts. An attempt at correlating rheology with sheen development resulted in the conclusion that the pigment and extender particle package is the greatest driving factor behind sheen reduction. The rheology modifier type and dispersant chemistry did not affect the flatness of the paint nearly as much. A Keyence VR-3000 series One-Shot 3D Measuring Macroscope was used to show that surface roughness does not directly correlate to the sheen value when a number of flat paints with different sheens were analyzed. This project is an ongoing effort and the information contained in this document will substantially help future development.

Novel paint driers based on iron co-ordination complexes were investigated for use as stoving finishes in oil-based coatings. Cis 9, cis 12-octadecadienoic acid was employed as a model vehicle because of its high drying capacity. Iron compounds generally have low catalytic efficiency at low temperatures which however improve with rises in temperature. The catalytic efficiency of some iron compounds was compared with those of some conventional driers at room temperature; 60 C, 80 C and 1200 C. To make the results comparative, equal weights of drier (0.05%) metal were employed in one series of experiments. In another series, a much higher concentration (0.25%) metal based on the weight of 9,12-octadecadienoic acid was employed. Equal weights of drier combination(s) and variable drier weights were examined to determine synergism or antagonism in the autoxidative systems. Maximum oxygen absorption, changes in iodine and peroxide values were monitored to determine a comparative catalytic performance of the driers at the reaction temperatures used. The reactivity of iron co-ordination complexes was found to be influenced by the organic compound with which the iron is chelated. Zerovalent iron complexes can be employed as high temperature driers. For convenience some common names have been used for major chemicals of importance in this work, e. g., Linoleic acid; cis 9, cis 12-octadecadienoic acid. Ferrocene; dicyclopentadienyl iron.

No description available.

O trabalho desenvolvido tem como objetivo avaliar um sistema de pintura anticorrosiva aplicado diretamente sobre o metal, sistema DTM, em relação a um sistema tradicional, composto por Primer, Intermediário e Top Coating, ambos base solventes e destinados para aplicações arquitetônicas, e propor o desenvolvimento e avaliação de formulações base água substitutas à base solvente, procurando-se determinar a influência de determinados componentes presentes nas formulações, tais como o dióxido de titânio, fosfato de zinco, caulim, inibidor de corrosão orgânico e agente reticulante nas propriedades anticorrosivas da tinta. São realizadas avaliações das propriedades anticorrosivas das tintas por meio de medidas de potencial de circuito aberto (EOCP), espectroscopia de impedância eletroquímica (EIS) e ensaio acelerado de corrosão em câmara de névoa salina. Além das propriedades anticorrosivas, as tintas DTM base água formuladas são avaliadas comparativamente à tinta DTM base solvente em outras propriedades, particularmente em relação à resistência à água, por meio de medidas de absorção de água, permeabilidade ao vapor dágua e determinação do ângulo de contato, e em relação às propriedades estéticas, tais como o poder de cobertura de tinta úmida e seca. Os resultados demonstram que o sistema DTM basesolvente apresenta desempenho anticorrosivo equivalente ao sistema tradicional. Dentre as formulações base água avaliadas, verifica-se que o uso do fosfato de zinco como pigmento anticorrosivo e de um agente reticulante na formulação é fundamental para se obter um desempenho anticorrosivo satisfatório. Também é demonstrado que a resistência à água dos filmes é um fator fundamental a ser melhorado nas tintas base água para que se possa obter resultados satisfatórios em relação à resistência à corrosão para longos períodos de exposição como o obtido para o sistema base solvente. / The developed work aims to evaluate an anticorrosive paint system applied directly on metal, DTM system, in relation to a traditional three components paint system, composed by Primer, Intermediary Coating and Top Coating - both systems solvent based and intended to architectural applications. The work also aims to develop and evaluate water based DTM paint formulations in substitution to solvent based paint system, determining the influence of some components present in the formulations, such as titanium dioxide, zinc phosphate, kaolin, organic corrosion inhibitor and a crosslinker agent, in the anticorrosive properties of the paint. The anticorrosive properties of the paint are evaluated by open circuit potential measures (EOCP), electrochemical impedance spectroscopy (EIS) and accelerated corrosion test in the salt-spray chamber. Besides the anticorrosive paints properties, water based DTM formulated paints are compared to solvent borne DTM paint in other properties, particularly in relation to water resistance, by measures of water absorption, water vapor permeability and contact angle, and also in relation to aesthetic properties, such as dry and wet hiding power. The results demonstrated that anticorrosive performance of solvent borne DTM paint system is similar to the solvent borne traditional paint system. In relation to formulatedwater based DTM paints, it was observed that the use of zinc phosphate as an anticorrosive pigment and a crosslinker agent in the formulation is essential to obtain a satisfactory anticorrosive performance. It is also demonstrated that the paint films water resistance is a fundamental property to be improved in water based paints in order to obtain satisfactory results in relation to corrosion resistance for long periods of exposure, just as observed for solvent borne system.

O trabalho desenvolvido tem como objetivo avaliar um sistema de pintura anticorrosiva aplicado diretamente sobre o metal, sistema DTM, em relação a um sistema tradicional, composto por Primer, Intermediário e Top Coating, ambos base solventes e destinados para aplicações arquitetônicas, e propor o desenvolvimento e avaliação de formulações base água substitutas à base solvente, procurando-se determinar a influência de determinados componentes presentes nas formulações, tais como o dióxido de titânio, fosfato de zinco, caulim, inibidor de corrosão orgânico e agente reticulante nas propriedades anticorrosivas da tinta. São realizadas avaliações das propriedades anticorrosivas das tintas por meio de medidas de potencial de circuito aberto (EOCP), espectroscopia de impedância eletroquímica (EIS) e ensaio acelerado de corrosão em câmara de névoa salina. Além das propriedades anticorrosivas, as tintas DTM base água formuladas são avaliadas comparativamente à tinta DTM base solvente em outras propriedades, particularmente em relação à resistência à água, por meio de medidas de absorção de água, permeabilidade ao vapor dágua e determinação do ângulo de contato, e em relação às propriedades estéticas, tais como o poder de cobertura de tinta úmida e seca. Os resultados demonstram que o sistema DTM basesolvente apresenta desempenho anticorrosivo equivalente ao sistema tradicional. Dentre as formulações base água avaliadas, verifica-se que o uso do fosfato de zinco como pigmento anticorrosivo e de um agente reticulante na formulação é fundamental para se obter um desempenho anticorrosivo satisfatório. Também é demonstrado que a resistência à água dos filmes é um fator fundamental a ser melhorado nas tintas base água para que se possa obter resultados satisfatórios em relação à resistência à corrosão para longos períodos de exposição como o obtido para o sistema base solvente. / The developed work aims to evaluate an anticorrosive paint system applied directly on metal, DTM system, in relation to a traditional three components paint system, composed by Primer, Intermediary Coating and Top Coating - both systems solvent based and intended to architectural applications. The work also aims to develop and evaluate water based DTM paint formulations in substitution to solvent based paint system, determining the influence of some components present in the formulations, such as titanium dioxide, zinc phosphate, kaolin, organic corrosion inhibitor and a crosslinker agent, in the anticorrosive properties of the paint. The anticorrosive properties of the paint are evaluated by open circuit potential measures (EOCP), electrochemical impedance spectroscopy (EIS) and accelerated corrosion test in the salt-spray chamber. Besides the anticorrosive paints properties, water based DTM formulated paints are compared to solvent borne DTM paint in other properties, particularly in relation to water resistance, by measures of water absorption, water vapor permeability and contact angle, and also in relation to aesthetic properties, such as dry and wet hiding power. The results demonstrated that anticorrosive performance of solvent borne DTM paint system is similar to the solvent borne traditional paint system. In relation to formulatedwater based DTM paints, it was observed that the use of zinc phosphate as an anticorrosive pigment and a crosslinker agent in the formulation is essential to obtain a satisfactory anticorrosive performance. It is also demonstrated that the paint films water resistance is a fundamental property to be improved in water based paints in order to obtain satisfactory results in relation to corrosion resistance for long periods of exposure, just as observed for solvent borne system.

Thesis (PhD (Process Engineering))--Stellenbosch University, 2008. / The feasibility of predicting paint properties directly from the raw material formulation as well as the rheological data is investigated in this study. Although extensive work has been carried out on the prediction of paint properties in terms of the raw material data, very little research has been carried out on the prediction of paint properties in terms of the rheological data. Little is known about the relationship between fundamental rheological properties and real-world performance. The paint under investigation consists of fourteen raw materials. These raw materials interact in a very complex manner to produce certain desired paint properties. Evaluation of these interactions in terms of constitutive equations is almost impossible and the relationships between paint properties, raw materials and rheology can only be modelled in a statistical way. Linear relationships are investigated with linear parameter estimation techniques such as multiple linear regression. However, it has been found that many of these relationships are non-linear and that linear modelling techniques are no longer applicable for certain situations, e.g. at very high concentrations of specific raw materials. Non-linear techniques such as neural networks are used in these situations. The relationship between the raw materials, paint properties and rheology are evaluated using the following three models: · MODEL 1: The relationship between rheology and raw materials · MODEL 2: The relationship between paint properties and raw materials · MODEL 3: The relationship between paint properties and rheology MODEL 1 makes use of techniques such as principal component analysis and preliminary modelling to respectively reduce redundancy and to capture as much data as possible. MODELS 2 and 3 make use of linear screening techniques in order to identify relevant raw materials and paint properties. The validity of every model is checked to ensure that predictions and interpretations are unbiased and efficient. MODEL 1 revealed that emulsion, extender particles, pigment, water, organic pigment and solvent are the six most important raw materials affecting the rheology of the specific paint. The rheology curves that are predicted most accurately by means of multiple linear regression are the “Amplitude Sweep” (AS), “3-Interval-Thixotropy-Test” (3-ITT) and the “Flow Curve” (FC). Non-linear rheological behaviour is encountered at high pigment volume concentrations (PVC) and volume solids (VS), due to the strong dependency of the rheology of the paint on these properties. It has been shown that neural networks perform better than multiple linear regression in predicting the rheological behaviour of these paint samples for which the raw materials vary by more than 20% from the standard formulation. On average, neural networks improve predictability of the rheological parameters of these samples by 54%. The largest improvement in predictability is made on the rheological variable “Extra Low Frequency” value (CXLF), where multiple linear regression resulted in relative errors of 59%, while neural networks resulted in errors of only 5%. Other predictions of rheology curves where neural networks have shown a major improvement on predictability are the “Time Sweep” (TS) – 68% increase in accuracy and “Low Shear” curve (LS) – 63% increase in accuracy. The smallest increase that the neural network had on the predictability of a rheology curve, was a 33% increase in accuracy of the “Amplitude Sweep” (AS) predictions. Multiple linear regression models of MODEL 2 predict the critical paint properties of Opacity, Gloss, Krebs Viscosity and Dry Film Thickness with relative errors smaller than 10%. It has been shown that 90% of all new predictions fall within the allowable error margin set by the paint manufacturer. Paint properties that can be predicted with an expected error of between 10% and 20% are Dry and Wet Burnish, Open Time and Water Permeability. Paint properties that are predicted the most inaccurately by MLR, that results in errors larger than 20% are Dirt Pick-Up and Sagging. Non-linear techniques such as neural networks are used to predict the paint properties of these paint samples for which the raw materials vary by more than 20% from the standard formulation. The neural networks show a major improvement on the predictability of the paint properties for those paint samples that vary more than 20% from the standard formulation. On average, neural networks improve predictability of the paint properties by 47%. The largest improvement in predictability is made on the Wet Burnish20 prediction, where multiple linear regression resulted in relative errors of 66%, while neural networks resulted in errors of only 0.6%. Other paint property predictions where neural networks have shown a major improvement on predictability of 80% or more in accuracy are Gloss – 80% increase in accuracy and Dry Film Thickness – 81% increase in accuracy. The smallest increase that the neural network had on the predictability of a paint property, was a 33% increase in accuracy of the Sag predictions. MODEL 2 makes it possible for the paint manufacturer to test tolerances around certain paint properties during manufacturing. Rheology is still a very under-utilised tool for explaining certain paint properties. MODEL 3 quantified the correlation between fundamental rheological properties and real world performance of a paint. It has been shown that rheological measurements can be used accurately to predict certain critical paint properties such as Opacity, Krebs Viscosity, Dry Film Thickness and Gloss within the allowable error margin given by the paint manufacturer. Multiple linear regression models predict the paint properties of Opacity, Krebs Viscosity and Dry Film Thickness with relative errors smaller than 10%, with rheology as input to the model. A neural network of MODEL 3 was developed to predict the paint properties of those paint samples that vary more than 20% from the standard formulation, by using rheology data as input to the model. The neural networks perform better than multiple linear regression in predicting the paint properties of these paint samples. On average, neural networks that use rheology data as input, predict the paint properties 49% more accurate than equivalent multiple linear regression models. The greatest improvement in model predictability is for Water Permeability - 73% increase in accuracy and Gloss - 70% increase in accuracy....

Thesis (MScEng)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Desired behaviour of paint during processing, storage, application and after application is of great importance in the coatings industry. Rheology (the study of flow and deformation behaviour) is used as a method to investigate the behaviour of the flow and deformation properties of the paint during these stages. Some of the more important phenomena that can occur during these stages, which were examined rheologically, are: 1. The rheological behaviour of certain complex raw materials during processing - vesiculated beads suspensions 11. The paint behaviour during storage - in-can stability, e.g. phase separation and sedimentation of particles; Ill. The paint during application - ease of application, spatter, etc.; IV. The paint behaviour after application - sag, layer thickness, levelling (ability to hide brush marks), etc. A rheometer was used to obtain rheological curves from a paint sample (± 1 ml). Correct interpretation of these curves, which display rheological properties of the sample such as the viscosity, shear stress, structural strength and many more, produced information about the properties mentioned in i, ii, iii and iv above. It was found that the rheological data correlated well with empirical tests carried out in the laboratory for spatter, sag, levelling behaviour and in-can stability of the paint. A wide variety of paints were studied ranging from tough/durable outdoor paints to smooth/velvety indoor paints. The rheological behaviour explained the specific end-use properties of the paints. Paints from two different companies were compared on a rheological basis. In some cases large differences in rheological behaviour were observed. Rheology modifiers were tested on a new paint. It was found that specific rheology modifiers could be incorporated into the formulation to give the specific rheological behaviour required. Rheological modelling was performed and it was found that the flow behaviour of paint cou1d be modelled accurately with existing viscosity models (Ostwald/de Waal, Bingham, Casson, Herschel-Bulkley, Cross and Philips-Deutsch). Other rheological properties of paint were also modelled successfully with a simple linear regression model. Rheology was also used as a method to examine the flow and deformation properties of vesiculated beads, a component of paint with very complex rheology. The most important factors that influence the rheological behaviour of the vesiculated beads were determined. It was found that the type of manufacturing process for the beads affected the rheological behaviour. The effect of the raw materials used to manufacture the vesiculated beads were rheologically determined. / AFRIKAANSE OPSOMMING: Dit is baie belangrik dat verf die gewenste gedrag moet toon tydens berging, vervaardiging, tydens aanwending en direk na aanwending. Reologie (die studie van vloei- en vervorming) word gebruik as a metode om die vloei- en vervormingseienskappe van verf gedurende bogenoemde stadia te ondersoek. Sommige van die belangriker verskynsels wat gedurende hierdie stadia kan plaasvind, is d.m.v reologiese toetse ondersoek. Die verskynsels is as volg: i. Die reologiese gedrag van komplekse grondstowwe soos gevesikuleerde partikel suspensies. ll. Verfgedrag tydens berging - stabiliteit van verf in die blik, bv. faseskeiding en sedimentasie van partikels lll. Verfgedrag tydens aanwending - gemak van aanwending, spatsels IV. Verfgedrag direk na aanwending - afsakking, dikte van verflaag, vloei-eienskappe 'n Reometer is gebruik om die reologiese kurwes te bepaal deur gebruik te maak van ± 1 ml monster. Korrekte interpretasie van hierdie kurwes, wat onder meer eienskappe soos viskositeit, spanning en struktuursterkte insluit, lei tot inligting wat die verskynsels in i, ii, iii en iv kan verklaar. Daar is gevind dat inligting wat verkry is i.v.m die verskynsel van spatsels, afsakking, vloei en die stabiliteit van verf in die blik, goed korreleer met empiriese toetse wat in die laboratorium uitgevoer is. 'n Groot verskeidenheid van verwe, wat wissel van duursame/sterk buitemuurse verf, tot fluweelsagte binnenshuise verf, isondersoek. Die reologiese toetse het daarin geslaag om die eienskappe van die eindproduk suksesvol te verduidelik. Verf van twee verskillende maatskappye is ook met mekaar vergelyk op 'n reologiese grondslag. Daar is by sommige van die verwe aansienlike verskille in die reologiese gedrag gevind. 'n Nuwe verf is gebruik om die uitwerking van reologie modifiseerders te ondersoek. Daar is gevind dat daar spesifieke reologie modifiseerders bestaan wat unieke reologiese gedrag verseker. Reologiese modellering is gedoen op verf en daar is gevind dat die vloeigedrag van die verf akkuraat gemodelleer kan word deur van die bestaande viskositeitsmodelle gebruik te maak (Ostwald/de Waal, Bingham, Casson, Herschel- Bulkley, Cross en Philips-Deutsch). Ander reologiese eienskappe is gemodelleer deur gebruik te maak van eenvoudige regressie modelle. Daar is ook van reologiese tegnieke gebruik gemaak om die vloei en vervormingseienskappe van gesuspendeerde gevesikuleerde partikels, wat as 'n grondstof vir verf gebruik word, te ondersoek. Die belangrikste faktore wat die reologiese gedrag beïnvloed het, was onder meer die verskillende prosesse waarmee die gevesikuleerde partikels vervaardig is. Die effek van sekere van die grondstowwe wat gebruik word om die gevesikuleerde partikels te vervaardig, is ook reologies ondersoek.