4. DESCRIPTION

A. FIELD OF THE INVENTION

The present invention relates to the dispersion of inorganic nanoparticles in polymer (which acts as binder solution) and plasticizer solution using hydrodynamic cavitation technique, which was designed for particular application.

B. BACKGROUND OF THE INVENTION

The present invention relates to dispersion of inorganic nanoparticles in thick viscous polymer matrix through hydrodynamic cavitation technique. The dispersion or mixing of nanoparticles in polymer matrix was the major research developed in this invention. The stability of the dispersion was the major issue addressed in this research work. The main phenomena of hydrodynamic cavitation is associated with the formation, growth and collapse of bubbles, which leads to the generation of high pressure and temperature and create a localized hot spots therefore the breakdown of agglomeration of the particle takes place, therefore the dispersion of solid particles in polymer takes place. Cavities in hydrodynamic cavitation are mainly formed due to change in pressure caused in a flowing fluid by varying its area or flow rate. This cavitation effect causes the turbulent shear stress on the surrounding liquid and high velocity. The flow area can be restricted by placing orifice or venture meters. A dispersion process takes place during cavitation, the collapse of a cavitation bubble near the boundary of the phase separation of a solid particle suspended in a liquid result in the breakdown of the agglomerated suspension. An emulsification and homogenization process takes place during cavitation, the collapse of a cavitation bubble near the boundary of the phase separation of a liquid suspended or mixed with another liquid result in the breakup of drops in the disperse phase. Thus, the use of kinetic energy from collapsing cavitation bubbles and cavities, produced by hydrodynamic means, can be used for various mixing, emulsifying, homogenizing, and dispersing processes. Devices are known in the art which utilize the passage of a hydrodynamic flow through pipes.

The dispersion of metal and metal oxide nanoparticles in polymer matrix of binder & plasticizer was carried out on .hydrodynamic cavitation setup. Inorganic nanoparticles synthesized using ullrasonication technique, of average range from 1-100 nm were used in the dispersion process. Different ratios of plasticizer and binder solution were taken into the feed tank and carried out the experiment for 10 min and then different amounts of different nanoparticles were added to it inorder to check the dispersion stability using hydrodynami'c cavitation technique by operating its flow rate and pressure.

Patent #8,936,392 - Justia Patents Database, invented the hydrodynamic cavitation setup for fluid streams used in high contaminant flow situations. It is made from the cylindrical tube having a flow through chambers arranged in a'manner which creates cavitations. Each chamber consists of three triangular shaped plates placed radically inward at an oblique angle to the chamber. Patent US20100059726 A I, invention relates to multicolor colloidal particles coaled with a metal nanoparticles mixture having colours in.the visible region and a method for preparing the same. In this work different metal particles of different colours were mixed in compositional ratio and coated with different polymers, the method for the same is developed. Patent US7727909 B2, invented a method to produce fine grained particles especially oxides. The invention is based upon the surprising discovery of one or more metals incorporation into a mixed metal oxide was done in a particulate matter instead of dissolving in solution. Patent US 5658653 A, this invention relates to the dispersion of crystalline mixer metal hydroxide particle in polymeric composites mixed with fliers. The polymeric composites of the invention have improved the toughness, retention and stiffness. By which the coefficient of expansion, was reduced and enhances the abrasion resistance and many other properties.

Patent US 5417956 A, invented a process for the preparation of nanophase solid state materials having crystallite morphology and particle size in the range I to 30 nm was obtained. It had a step by step process of mixing, pressurizing, increasing shear by passing it in fluidizer, - depressurizing and separating from the mixture, the whole process was done through cavitation process. Patent US 8309479, this invention relates to the process developed for metal coating of nano-fibers in general simple, inexpensive method generating metal coated electronic fibers. Patent WO 2008066995 A2, this invention reveals the method of changing rheology in filled resin using cavitation technique. The viscosity change is made through changing ratios and cavities producing, by changing morphology of the particles and type of material such as organic, inorganic etc., by using different resins under controlled cavitation. US patent 5492654 A, invented a method to obtain a free disperse system which will make it possible to regulate the intensity of the hydrodynamic cavitation setup and to select its parameter according to the properties of components of the flow under treatment. The components consist of physico-chemical characteristics therefore a device was developed by placing baffles with in hydrodynamic cavitation set up which allows the multiplicity of the treatment and will be regulated by increasing the degree of cavitation. Therefore the quality of the dispersion is improved and a free disperse system was obtained. US patent 6502979 Bl, invented a device and a method to create hydrodynamic cavitations in fluid. This method can find applications in areas such as oil processing, petroleum chemistry, organic & inorganic synthesis. In this method the device was developed for creating cavitations in fluids comprising a flow-through chamber and intermediate through an inlet and an outlet opening and the flow through chamber having an upstream opening portion communicating with the inlet opening and the downstream operating with the outlet opening and the cross-sectional area was also considered.

US patent 0140047 Al, invention relates to the method for the surface application of chemical compounds to both synthetic and natural fibers. This was used in the wide variety of differentiating properties to fibers in silver form through its surface treatment. In this sonochemical reaction the oxidation or the reduction process described above was not limited to only a silver compound or copper compound. It can also be applied to any solid insoluble or poorly soluble compound in solution that can be reduced to a solid from the solution. WO patent 2002040142 A2= invented a device and method for creating hydrodynamic cavitation in fluids particularly for creating and controlling cavitations effects in fluids in both quantitative and qualitative process with in the position of structural components. In this method the annular orifice formed between the flow through chambers and the perimeter of the first baffle element creates the cavitations. The annular orifice increases as the first baffle element moves downstream along the chamber.

WO patent 2010089759 A2, invented the hydrodynamic cavitation reactor to achieve tailored cavities in aqueous and non- aqueous media, for intensification of the physical and chemical processes and a method for designing such reactor. In this it produces a stable cavitation as a function of density and viscosity. The cavitation conditions generated were represents as percentage cavitational activity or simply dissolution characteristics.

US patent 0053545 Al. invention relates to the controlled formation of cavitation bubbles that serve as autonomous chemical mini-reactors and use the energy released during implosion of these bubbles to rapidly alter complex hydrocarbon mixtures from crude oil. This method of fast hydrocarbon mixture modification comprises pumping a fluid in channels provided with a local constriction of the flow-through hydrodynainic multi-stage cavitation device with the controlled inlet pressure and using reagents conditions of choice.

US patent 0135902 Al, invented a method for industrial-scale production of metal matrix nanocomposites. This method can be used for the batch production in a volume of molten metal housed within the cavity of the production chamber. Apparatus comprises the production chamber defining a cavity, a nanoparticle feeding system, nanoparticle mixing system, a cavitation system and a pumping conduit. The pumping conduit can be configured to conduct a flow metal held in the production chamber cavity from the se cond impeller into the cavitation cavity through the input aperture.

The review of the prior methods revels following drawbacks / limitations:

• In vertical/horizontal planetary mixers mixing does not occur uniformly, and it takes longer mixing cycles without homogeneous dispersion of particles.

• No process is developed for dispersion of nanoparticles in high viscosity polymer solution. Necessity has constantly been felt to develop a production route which aims:

• To attain a good homogeneous dispersion at normal temperature.

• To carry out the dispersion/mixing process at large scale.

• To build up a large magnitude of energy in small area and achieve the dispersion in small time and cost effectively.

5. OBJECTIVES OF THE INVENTION

I. Sophisticate equipment was designed for producing cavitations using orifices of different sizes.

2. Developed an energy intensified process for the dispersion of different inorganic nanoparticles in high viscous polymer matrix in different ratios.

3. A homogeneous dispersion is attained by adding 10 - 15 % of inorganic nanoparticles in polymer and plasticizer solution.

4. This method gives the best homogenous dispersion than sonication and other process used for dispersion such as planetary milling, wet milling, helical mixer etc.

6. SUMMARY OF THE INVENTION

A device and a method was designed for the dispersion of inorganic nanoparticle in polymer matrix using hydrodynamic cavitation, where the cavitations occurred by placing the orifice of different size and there by maintaining cavitation impulse. A homogeneous dispersion solution is attained at reasonable cost at very less time. The cavities were produced due to restriction of flow using orifice plate. Therefore high pressure is developed which leads for the better dispersion of nanoparticles.

7. DETAILED DESCRIPTION OF THE INVENTION

Features and advantages of the invention will become apparent in the following detailed description and the preferred embodiments with reference to the accompanying drawing. The main objective of the invention was to obtain a homogeneous dispersion of metal nanoparticles in high viscous polymer matrix through hydrodynamic cavitation process. The design of the equipment setup was shown in figure I. The pump used in this process is double piston pump of 1.5 Hp. Example I: I. The composition is formulated as per self esteemed models.

2. A thick high viscous fluid (1-4 cenlipoise) which acts as a binder and a plasticizer was taken in the required proportion (weight ratios range from 1: 10 to 1:100 and 1:1 to 20:1) in the feed tank, and the cavitation process was carried out for 10 min by maintaining both pressure and flow rate with 1 mm orifices.

3. A metal and metal oxide nanoparticle of different sizes from 1-100 nm range (in different ratios of solid particles) was added slowly to the tank. The mixture is stirred with a glass rod for proper mixing (preventing agglomeration) of the particle into the slurry.

4. The experiment was carried out for about 30 min through I mm orifice size at a flow rate varying in the range from 10-50 mL/s.

5. A homogeneous dispersion of inorganic nanoparticles in plasticizer and polymer solution was obtained.

8. DESCRIPTION OF PROCESS THROUGH HYDRODYNAJV1IC CAVITATION TECHNIQUE

Cavitation is a subject of interest in a number of fields in science and engineering.-Cavitation may occur in various pipe components such as valves, orifices, elbows and tees in any place where low pressure and high velocity was reached along with change in temperature. The effect of cavitation developments can be noticed first from the noise and later vibrations, then erosion all through the pipeline. The cavitation process combines the volume of fluid technique predicting the formation of nuclei, growth of the bubble and collapse. Hence the bubble liquid flow was treated as single fluid homogeneous flow. The bubble growth was described by the Rayleigh-Plesset equation. . The development of cavitation phenomena depends on many factors like pressure, flow rate, depressurization rate, surface conditions, dissolved gases present in the fluid, impurities, solid particles loading, surface irregularities of the pipe line.

The specification of the equipment is as follows:

Capacity- 1.5 Hp; Viscosity of the fluid can be used upto-6 centipoise; Temperature - 303-473 X; Flow Rale - (0.5-5)* 10"6 m3/s ; Piping Material - SS-304/305; Pipe inner diameter - 1 mm: Upstream pressure - I - 20 Bar; Sample collector Vessel Capacity - 50L; Vessel Material - SS-304. The hydrodynamic cavitation setup consist of a feed tank of 10 L capacity, from there the inlet feed to the system was passed with a controlled flow wall foremost to the pump (2 piston plunger pump of capacity 1.5 Hp) where a adjustable and safety flow valves were attached to the pump. By adjusting the flow meters the feed was passed to the orifice (circular orifice) with a controlled flow rate where the cavities were created and then the composite solution was collected as outlet in the same tank. The excess feed from the orifice was collected through bypass or purge system placed ahead of the orifice. The process continuous for a specified time and here the term hydrodynamic dispersion denotes the spreading or mixing (at a very macroscopic to nanoscopic level) that results from both mechanical dispersion and molecular diffusion.

10. CLAIMS:

A device and a method was designed for ihe dispersion of inorganic nanoparticle in mixture binder matrix using hydrodynamic cavitation, where the cavities were occurred by incorporating orifices of different size in the pipeline. A homogeneous dispersion of nanoparticles in polymer matrix was prepared by the above method.

We Claim:

1. The successful dispersion of inorganic nanoparticles in thick mixture binder solution was developed through hydrodynamic cavitation technique.

a. Formulation for low viscous fluid - by taking binder solution in low quantity in large quantity of plasticizer to prepare a low viscous polymer solution.

b. Formulation for high viscous fluid - by taking large quantity of binder solution and less quantity of plasticizer inorder to prepare a high viscous polymer solution.

2. A methodology for claim I was incorporated in this work by using orifice as the key parameters to build cavities.

3. A methodology for claim 2 was carried out by maintaining flow rate and pressure of the fluid in order to maintain the pressure drop throughout the process in order to build cavities.

4. A methodology according to claim 1 ihe discharge coefficient of the orifice is maintained constant by keeping flow rate constant. So that the cavities occurred in all the runs would be equal and study that as a parameter.

5. A complete methodology was developed from claim 2, 3, 4 to follow the claim I procedure.