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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. 

EPC

Wetting Phenomena under High Pressure and Vacuum Conditions

Wetting Phenomena under High Pressure and Vacuum Conditions

High pressure and high temperature applications can easily be found in many areas, from basic and fundamental research to inevitable utilization in oilfields where gas injection, thermal injection, steam flooding and  fire flooding technique are applied to enhance oil recovery.  Our various chambers, attachable to OCA and DCAT devices are available for temperature control from -30 to 1900C, pressure control from 10E-7 mbar to 750 bars and humidity from 0% to 100%. 

Our devices which can help you: OCA15, OCA25, OCA50, DCAT EZSM, MTFQ, HTFC, NHD, TEC, EFC, PMC, HGC, 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

Surface Structures Fabrication and Verification

Surface Structures Fabrication and Verification

A fine (micro- or nano-patterned) Si-based mold is fabricated by a conventional VLSI process and the mold is directly pressed to a thin glass plate using a hot-press machine.  Fabrication of fine grating on a glass surface can be achieved by imprint lithography using a Si3N4/SiO2/Si mold and a low Tg glass. The imprint conditions are designed based on the glass surface property measured under a temperature, humidity or pressure controlled condition.  Recently micro-fluidics research will rely on the similar imprint and etching processes to create the desired patterns or channel designs as another example in other modern applications.

FDS/Dataphysics can help in the steps  of  your VLSI processes 

Lithography is used to transfer a pattern from a photomask to the surface of the wafer. The photoresistant coverage and wetting nature on the wafer surface will determine the effectiveness of the partner trafer when exposed to (often ultraviolet) light or another source of illumination (e.g. X-ray).  Therefore, the surface preparation of the wafer and selection of photoresistant needs to be checked with a contact angle meter OCA and tensiometer such as DCAT, t15, t100, etc.

Etching is used to remove material selectively in order to create patterns.   The selectivity and completeness of the etching are always desired by the process engineers and they can be verified with a contact angle device, OCA.

Deposition- A multitude of layers of different materials have to be deposited during the IC fabrication process. The two most important deposition methods are the physical vapor deposition (PVD) and the chemical vapor deposition (CVD). During PVD accelerated gas ions sputter particles from a sputter target in a low pressure plasma chamber. The principle of CVD is a chemical reaction of a gas mixture on the substrate surface at high temperatures. The need of high temperatures is the most restricting factor for applying CVD. This problem can be avoided with plasma enhanced chemical vapor deposition (PECVD), where the chemical reaction is enhanced with radio frequencies instead of high temperatures. An important aspect for this technique is the uniformity of the deposited material, especially the layer thickness.  You can use an OCA device to check on the uniformity of the deposited material.

Chemical Mechanical Planarization– Processes like etching, deposition, or oxidation, which modify the topography of the wafer surface lead to a non-planar surface. Chemical mechanical planarization (CMP) is used to plane the wafer surface with the help of a chemical slurry. First, a planar surface is necessary for lithography due to a correct pattern transfer.  The CMP slurry formulations can be optimized with a DCAT tensiometer or a MutiScan and the planarity of the wafer after CMP can be examined with a fully automated OCA50 contact angle scanning and mapping features.

Oxidation is a process which converts silicon on the wafer into silicon dioxide. The chemical reaction of silicon and oxygen already starts at room temperature but stops after a very thin native oxide film. For an effective oxidation rate the wafer must be settled to a furnace with oxygen or water vapor at elevated temperatures. Silicon dioxide layers are used as high-quality insulators or masks for ion implantation. The quality of the formed silicon dioxide can be examined with an OCA25 equipped with a temperature, humidity or pressure chamber.

Ion implantation is the dominant technique to introduce dopant impurities into crystalline silicon. This is performed with an electric field which accelerates the ionized atoms or molecules so that these particles penetrate into the target material until they come to rest because of interactions with the silicon atoms. Ion implantation is able to control exactly the distribution and dose of the dopants in silicon, because the penetration depth depends on the kinetic energy of the ions which is proportional to the electric field.  With an OCA25 and one of environmental chamber for either electrical field, pressure, temperature or humidity, you can research for an optimized ion implantation process.

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.

Coatings and Adhesives

Coatings and Adhesives

In coating and adhesion/bonding operations, it is vital that the adhesive and paint are applied in the correct locations and spread over properly treated surfaces to achieve needed coverage and bond. Poor formulations and incorrectly applied adhesive/paint can weaken the bond and undermine the coating effect.  Hardening of the adhesive( the so called shark skin of the coating) can be done through cooling, drying or curing reactions, prior to bonding and surface formation; overspreading or over-absorption into permeable materials can weaken the subsequent joint and adhesion. The techniques for characterizing the properties of surfaces and formulations that influence the interactions between the substrate and adhesive/coating during the bonding and surface finishing processes are critical. These methods include  substrate wettability and surface energy, surface absorbency, surface receptivity and modification, application and spreading monitoring.  Good wettability of a surface is a prerequisite for ensuring good adhesive bonding and surface finishing. In the meantime, some important issues need to be focused on developing a better formulation for a liquid adhesives and coating include: enhancing dispersion – maximizing pigment coverage; increasing solubility – increasing component loading; and reducing viscosity –  reducing mixing requirements, enhancing flow-ability and wetting.

The team of FDS/SITA/Dataphysics can help you with our years of application experiences not only in surface treatment and verification, but also the dynamic processes of applying your adhesives and coatings to any surface.  

Our devices which can help you are: OCAs, DCATs, DCAT-LBE, ODG, RN4.2, LK2.2, T100, T15Plus, etc.