Centre for Sol-Gel Coatings (CSOL)
Pilot Plant for the Large Scale Synthesis of Sols
A pilot plant for the synthesis of inorganic and organic-inorganic hybrid sols has been set up. It consists of three reactors of capacities 100 l, 20 l and 10 l with storage vessels of various capacities (from 30 l up to 200 l) attached to the respective reactors. Known quantities of the precursors or reactants can be transferred from the storage vessels into the reactors. Small additions of chemicals can be precisely controlled through suitable dosing systems, provided. The reactors can be operated in the temperature range -5oC to 150oC. The plant is equipped with sophisticated process controls and safety mechanisms for efficiently producing large volumes of sols. The prepared sols can be collected in receivers and transported for coating, curing and densification.
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Atomic Force Microscope (AFM)
Model No & Make :
Park XE7 (Direct On-Axis Manual Focus Optics)
Specifications
- XY Sample stage : 13 mm x 13 mm
- Scan Range in XY : 50 µm (max)
- Scan Range in Z : 12 µm (max)
- Options : Non Contact, Contact, Dynamic Contact, Phase Imaging. Heater Stage and Lithographic.
The atomic force microscope (AFM) is extensively used in material science and biological sciences. Characterization of sol-gel thin film surface morphology in sub-micron scale is necessary to evaluate their function properties in a wide variety of applications. It has been known that sub-micron and nanoscale properties control various aspects of functional performance. For example, enhanced transmittance in borosilicate glass (BSG, 91%) over soda lime glass (SLG, 89%) is due to sub-nanometer surface morphology of BSG. This may occur due to its different chemical composition though the refractive indices are comparable.
Coating Equipment
Flat spray unit
A spraying unit for flat substrates of varying dimensions up to 600 mm x 600 mm is available at the Centre. The sample table has a maximum displacement of 2000 mm. A variety of coating parameters, such as the transverse and lateral speeds of the spraying nozzles along with the table speed can be controlled to obtain coatings of desired quality. The unit is attached to a drying oven for baking the coatings prepared.
Spray coating line
A chain type coating line equipped with 95 spindles for coating of symmetrical components has been installed and commissioned. The unit is capable of coating up to 900 components per hour and the conveyor speed can vary from 1 to 15 parts per min. The coated components can be heated / dried in an adjoining IR chamber. The dimensions of a typical component that can be handled are 200 mm height and 150 mm diameter.
Spin coater
Two desk top spin coating units are available for carrying out experiments at the lab scale. The largest sample that can be handled for spin coating would be a wafer of dimensions 200 mm x 200 mm.
Dip coater
A table-top dip coater, is available for carrying out lab-scale experiments on 100 mm square substrates of up to 5 mm thickness. Variable withdrawal speed allows control over film characteristics such as thickness and uniformity. Angle dependant dip coater-can take up 1 m x 1 m substrates and can be tilted up to an angle of 15 degrees.
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Weathering Resistance Measurement System
Model & Make
Xenon test chamber model XE-3-HBS, Q-Lab Corporation, USA
Specifications
- Number of xenon lamps: 3
- Possible temperature range of test chamber: 25-110oC
- Range of relative humidity control : 10-95%
- Appropriate filters available for simulation of solar radiation behind window glass as well as for outdoor solar radiation
Details
The xenon test chamber is a laboratory testing facility to evaluate the product durability for indoor as well as outdoor conditions by exposing the product to simulated weather conditions. This accelerated testing facility has mostly been used in development and durability evaluation of paints/coatings for corrosion protection, anti-reflective, anti-tarnishing application as well as in the evaluation of the UV/weather resistance of polymer products/coatings.. The Q-SUN tester's user interface is designed to be functional, highly reliable and easy to use. Xenon arc lamps produce the most realistic reproduction of the full spectrum of solar radiation. The humidity and temperature corresponding to varying weather conditions can also be simulated accurately.
Centre
Centre for Sol-Gel Coatings
Weathering resistance measurement system
Variable Angle Spectroscopic Ellipsometer
Model & Make
VASE - 32, J.A.Woollam Co.Inc
Specifications
- Wavelength range: 400 to 1700 nm
- Angle of incidence: 40 to 85o
Details
Spectroscopic ellipsometry (SE) is routinely used to characterize both thin film and bulk materials for film thickness and optical constants, because of its simplicity in data collection without requirement of any reference sample. Moreover, an ellipsometry is more accurate than intense reflectance or transmittance measurements, because SE measures the relative phase change rather than the absolute intensity of the reflected or transmittance. VASE 32 is a rotating analyzer ellipsometer. The input polarizer is fixed, while the analyzer continuously rotates. Data acquisition is perfectly synchronized without use of position encoders. A monochromator is placed before the sample to study photosensitive materials. The ellipsometer is equipped with synchronous detection techniques to reject ambient light and allows data to be acquired even with room lights on. The angles of incidence can be varied automatically with a vertical sample mount.
Centre
Centre for Sol-Gel Coatings
Variable Angle Spectroscopic Ellipsometer
UV - Curing system
Model & Make
Conveyorised 3 Lamp UV Curing System, Advance Curing Systems, Bangalore
Specifications
- Light source : Medium Pressure Hg Quartz Lamps
- Power : 300 W/inches (each lamp)
- Curing width : 1000 mm (Max)
- Belt speed : 0.5 to 15 m/min
- Component Height : 25 mm
- Cooling : Centrifugal Blowers
- Mode : Auto and manual
Details
The main advantage of use of organic-inorganic hybrid coating systems is the use of low temperature radiation assisted curing for densification of coatings. The importance of ultraviolet (UV) curing especially realized when functional coatings like scratch resistant coatings, antireflective coatings etc. need to be cured on temperature sensitive transparent plastic substrates like polymethylmethacrylate (PMMA) and polycarbonate (PC). The unit is conveyorised having three lamps emitting UV radiation. The power of each UV lamp can be controlled individually. The centrifugal blowers attached to each lamp help to cool the substrate and remove the volatile organic by-products upon UV irradiation. A part of the equipment (substrate feed in) is placed inside the clean room and the lamps along with the hoods are placed outside the clean room. The conveyor belt is capable of an automated reverse motion, so that once curing has been completed during the forward motion of the belt, the cured substrate is brought back into the clean room due to the reverse motion of the conveyor belt.
Centre
Centre for Sol-Gel Coatings
UV Curing system
uv-curing-system-Inside-clean-room
IR - Curing System
Model & Make
Oven type Near Infra Red (NIR) Curing System, Advance Curing Systems (ACS), Bangalore
Specifications
- Heating source : Near Infrared Lamps
- Number of lamps : 6 Nos
- Power : 27 kW
- Heating area : 250 mm x 120 mm
- Temperature control : Thyristor with PLC
- Max Temperature : 350oC
Details
The absorption of NIR radiation by organic molecules leads to molecular vibrations that generates the heat by the material itself. This phenomenon has various applications such as in drying, evaporation, gelling and hardening etc. of coatings/materials. Use of IR radiation for curing of coatings has the advantage of efficiency, energy saving and better performance when compared to conventional curing method. The available NIR curing facility has IR emitters with gold reflector so as to utilize 95% of the available radiation to cure the work piece surface.
Centre
Centre for Sol-Gel Coatings
IR Curing system
Portable hand held Emissometer
Model & Make
AE 1, Devices & Services Company, Texas, USA
Specifications
- Measurement area : 0.75" (in flat samples); 1.0" (in tube samples)
Details
The portable emissometer measures the thermal emissivity of a material/coating. Thermal emittance measurements with the emissometer require that the high and low emittance standards and the sample to be measured be maintained at the same temperature. To achieve a uniform temperature, the instrument is provided with a heat sink on which the standards as well as the sample (normally flat) is to be mounted. Appropriate adapters can be used to measure the emittance of curved profiles also. The accuracy or repeatability of the instrument at room temperature for any particular measurement is high.
Centre
Centre for Sol-Gel Coatings
Portable hand held emissometer
Thin Film Analyzer
Model & Make
F20, Filmetrics Inc., USA
Specifications
- Thickness range : 15 nm to 50 µm
- Accuracy : 1 nm
- Precision : 0.1 nm
- Stability : 0.07 nm
- Wavelength : 400 to 1000 nm
Details:
The thin film analyzer works based on the intensity measurement of reflecting and transmitting light through the sample. Hence, thickness of only transparent coatings can be measured, though the substrates can be of transparent or non-transparent nature. There are possibilities of using a contact or a non-contact probe depending upon the nature of film and the substrate.
Centre:
Centre for Sol-Gel Coatings
Thin Film Analyzer
Viscometer
Model & Make
ViscoLab 4100, Cambridge Applied Systems, Inc
Specifications
- Viscosity : 0.2 to 10,000 centipoise
- Minimum sample required : less than 2 ml of fluid
- Operation temperature : -40 - 90oC
- pH of the fluid : 2.5 - 11
- Time required per sample: 30 minutes
Details
The vibrational viscometer, has been used to study rheological behaviour of ceramic powder suspensions. The principle of measurement of viscosity in a vibrational viscometer is based on damping of an oscillating electromechanical resonator immersed in a fluid whose viscosity is to be determined.
Centre
Centre for Sol-gel Coatings
