Surface Science Specialists:

Rheology of Emulsions

Home / Posts tagged "Rheology of Emulsions"
Electrical Wetting Phenomena

Electrical Wetting Phenomena

The electrowetting effect has been defined as “the change in solid-electrolyte contact angle due to an applied potential difference between the solid and the electrolyte”. The phenomenon of electrowetting can be understood in terms of the forces that result from the applied electric field.  It is also known that the contact angle supression or saturation phenomenum through voltage can be affected by changing the detailed geometry of the system.  It is predicted that  in reversed electrowetting, the contact angle can possibly grow with the voltage.

Electrowetting is now used in a wide range of applications from modular to adjustable lenses, electronic displays (e-paper) as well as switches for optical fibers. Electrowetting has recently been evoked for manipulating Soft Matter.  Furthermore, filters with electrowetting functionality has been suggested for cleaning oil spills and separating oil-water mixtures.  By optically modulating the number of carriers in space-charge region of the semiconductor, the contact angle of a liquid droplet can be altered in a continuous way.  This is called photoelectricalwetting and it can be observed if the conductor in the liquid/insulator/conductor stack used for electrowetting is replaced by a semionductor.

Our devices which can help you: OCA15, OCA20, OCA25, OCA35, OCA50, TEC, EFC, PMC, HGC, Electro-wetting platform EWP100, etc. 


Nano/micro Surface Treatments

Nano/micro Surface Treatments

Researchers work on proprietary particle coating and surface treatment technology to tailor the surface properties of the nanoparticles. By discreetly encapsulating individual particles with various chemical and physical processes, they are able to meet a customer’s performance requirements by controlling the particle size distribution, ensuring compatibility with the customer’s formulation, and including beneficial additives to control pH or rheology, to name a few.  In most instances, it is beneficial to mediate the interface between the nanoparticle surface and the application matrix in which the nanoparticles are to be utilized.  For example, for a naturally hydrophilic nanoparticle to be used effectively in non-polar media such as cosmetic oils, the surface of the particle may need to be rendered hydrophobic for uniform dispersion, compatibility, and performance.  The proprietary chemistry and process technology used to prepare these dispersions ensures that the customers receive ready-to-use products in which the nanoparticles are stabilized at their primary particle size, with no secondary structure or agglomeration.  The purpose to develop an optimized process is to impart a wide range of functionality to the particles, which not only ensures the success in the application but also provides the required flexibility in formulation with their nanoparticles.  The effectiveness of these surface treatment and coating processes can be examined, verified and optimized with our precision instruments such as OCA, DCAT, ODG and T-100 on the produced particle samples in either dry powder or pre-dispersed format.

Our devices which can help you: OCA15, OCA25, OCA50, DCAT11, DCAT21, ODG, T100

Foam Generation and Stability

Foam Generation and Stability

A foam is a colloidal dispersion in which a gas is dispersed in a continuous liquid phase. Many examples of foams in industry and everyday life can be found easily such as shampoo, bubble bath, dishwater detergent, cleaner, laundry, coffee, beer, beverages, soda, mining process, oil recovery, environment remedy, and so on. Solid foams, dispersions of gas in a solid, are not covered in this statement.

Do you like or hate foams?  For some refiners, in which the through-flow of gas at high temperature, pressure is required to crack hydrocarbons, the gas-liquid mixtures will foam strongly. The foam traps gas with gas fractions of 80% or higher.  Clearly in such situations, in which it is desired that solid catalysts contact liquids, the production of foam is not wanted. On the other hand, there are applications where foams are useful.  For example foams can have a high stress yield  and can be used in a fluid for carrying particles in applications ranging from the transport of cuttings in drilling, to the placement of sands in cracks in oil producing reservoirs, to increasing the conductivity of reservoirs for secondary oil recovery. Obviously, bubble bath and shampoo companies should like to produce appropriate foams for dish and hair washing.  Therefore, technologies which are impacted by foams and foaming are widespread.  And you have to deal with them.

Realistically, foams are not well understood and they are very hard to control.  A foam cannot be created without the vigorous introduction of gas from a bubbly mixture. To understand foaming it is necessary to try to be precise about the critical values of bubble release required to make and maintain a foam.  All liquid/gas foams are unstable, and some are more unstable than others.  The stability of foams is another subject in which our understanding is far from complete. Foams collapse by draining and film rupture. To keep a foam from collapsing it is necessary to oppose the draining by surface tension gradients induced by surfactants.  Therefore, the selection of surfactant through an effective foam testing to design an appealing formulation for the market is critical.

SITA R2000 and its versatile functional modules can help you understand all these important topics with a foam Its fully automated features enable you to measure the foam’s ease of generation, stability, drainage, density, and many other foam properties.  An interfacial rheology device, OCA25+ODG25 and bubble tensiometer SITA T100 will help you identify key factors which play important roles in determining the effectiveness of your formulations.  Speak to our experienced scientists to start making changes for your business.

Cleaning Processes Optimization and Validation

Cleaning Processes Optimization and Validation

There is a tremendous amount of types of industrial parts and surfaces required for cleaning before they become a finished product for users.  All the relevant processes or procedures to respond to the required cleanliness, whether they are chemical or physical methods will be interested in the effectiveness of their cleaning processes and cleaning formulations. The industry which is involved in cleaning process is widespread.

  • Cleaning equipment systems and cleaning reagents for
    1. wet cleaning processes
    2. thermal processes
    3. blasting processes
    4. special processes
    5. mechanical processes
  • Systems for drying processes will need to check on water stains or chemical leftover
  • Processes and systems for corrosion protection and preservation
  • Reagents for corrosion protection and preservation
  • Processes and systems for quality assurance
  • Clean room systems
  • Surface treatment systems
  • Processes and techniques in recycling and disposal
  • Components for cleaning systems
  • On-line automation cleaning systems
  • Cleaning products

SITA CleanoSpector, SITA ConSpector, SITA Cleanline ST, SITA Cleanline CL for direct cleanliness validation and the Dataphysics OCA devices for contact angle measuring are all available for both batch and on-line cleanliness checking to help you maintain and optimize your cleaning requirements.

Enhanced Oil Recovery/Oil Drilling/Petroleum Geology

Enhanced Oil Recovery/Oil Drilling/Petroleum Geology

Enhanced Oil Recovery (EOR) technologies are used to increase the amount of oil that can be extracted from an existing oil field after the primary and secondary production stages. These technologies play on the physics of how oil is trapped in the rocks and are primarily aimed at either decreasing the interfacial forces holding the oil in pores within the rock formation, reducing the viscosity difference between the oil and water phases, or modifying the reservoir and oil properties to release the oil more easily.

With increasing global energy demand, high-sustained oil prices, aging oil fields and a scarcity of conventional oil discovery, enhanced oil recovery techniques are set to play an increasingly important role in the global oil industry over the coming decades.  Although some short-term downturns occurred through the years, the growth rates and EOR methods employed vary considerably from country to county; a strong growth in oil recovery is still anticipated in each of the three main EOR sub-markets: thermal, gas and chemical.

Application scope for EOR:

-Identify commercially available additives, which are effective in reducing the mobility of carbon dioxide (CO2), thereby improving its efficiency and yield in the recovery of tertiary oil

-The control and/or  reduction in oil saturation  with a waterflood-containing surfactant concentration

-The use of foam to lower the mobility of gases used to displace oil

-Visco-elasticity measurements at varying shear help explain the dramatic change in gas/liquid/oil mobility

-Selection of the added surfactants and water-soluble polymers

-Environmental remedy and protection issues


Our devices which can help: OCA, DCAT, SVT20, ODG25, T100, T15+, etc.

Cosmetics and Personal Care Products

Cosmetics and Personal Care Products

The cosmetics/personal care industry develops and manufactures products such as cosmetics, soaps, detergents, and more, which are used for personal hygiene and beautification.  The global beauty market is usually divided into the following main business segments: baby and child care, bath and shower, color cosmetics, deodorants, depilatories, fragrances, hair care, men’s grooming, oral care, toiletries, skin care, and sun care.  These segments are complementary and through their diversity are collectively able to satisfy all consumers’ needs and expectations.

Personal care formulators/chemists work to understand the chemical and physical processes that describe how raw ingredients work, how they affect each other, and how they affect the manufacturing process. They design and manufacture new ingredients or combine and modify existing ingredients in new ways to create new products. Therefore, they need to make sure that desirable properties are maintained when ingredients are changed; they are continually trying to develop better and more cost-effective products.  In product development, cosmetic and personal care formulators need innovative solutions to successfully develop and introduce new products that will deliver tangible benefits to their customers.  FDS/SITA/Dataphysics’ experts are continually seeking new methods to help our customers and new formulators for their following purposes:

– Manage the product development process, from small scale laboratory to pilot plant to commercialization scale

– Monitor potential product formulations for stability over time and under varying levels of light and heat

– Selecting and testing new pigments, herbal and botanical ingredients, while reducing and eliminating e.g., synthetic ingredients and allergens

-Testing potential products for resistance to bacterial growth, settling, separation, agglomeration, coalescence

– Bring products to market faster and with more appeal

Our precision devices which can help you: OCAs, DCATs, SVT20, T100, T15+, Dynotester, etc.

Interfacial Rheology

Interfacial Rheology

Interfacial transport phenomena are of specific importance in the applications of multiphase fluid systems (complex fluids-suspensions, dispersions and colloids), which possess a large specific surface. Microscopically, the formation of long-range ordered structures inside the created thin films has many implications of both fundamental and practical significance. Applications of interfacial transport phenomena can be found in many areas: separation processes such as distillation, flotation, and liquid membranes; concerns of processing, flow and stability of emulsions, foams and particle dispersions; ink-jet printing; paints/coatings; wetting; etc.  To understand the dynamic process of lamination or multi-layering, which rearranges microstructures in sub-micron thin liquid films, can serve as an important tool for probing the long range interaction forces in concentrated particle suspensions and colloidal dispersions.  The dynamic surface tension and dynamic viscosity (including linear and non-linear interfacial viscoelasticity) are crucial in knowing  their creation, characteristics and stability for such systems of containing layered films.

The team of FDS/Dataphysics/SITA is a unique one in the market, with in-depth experience not only in surface science and interfacial rheology but also in manufacturing precision tensiometers and rheometers (we are not depending on external licensing as others) . 

Our devices which can help you are: OCAs, ESr-O, ODG, DCAT-LBE, T100, T15Plus, etc.