This document presents research on developing a lead-free and environmentally-friendly substitute for PVDF polymer composites. It investigates using potassium sodium niobate (KNN) ceramic as a filler material in a polyacrylonitrile (PAN) polymer matrix composite. KNN is identified as a promising substitute due to its comparable piezoelectric and dielectric properties to lead-based ceramics, as well as being non-toxic. The document outlines the experimental process of fabricating PAN/KNN composites and evaluating their properties through various characterization techniques. Future work is proposed to further optimize the composite properties by controlling parameters like KNN particle size and volume fraction in the polymer matrix.

1. Presented by
Rohan R. Parsewar (MIS No. 111111038)
Hanmant A. Gawade (MIS No.141211005)

2.  Introduction
 Objective
 Literature Survey
 Experimental Work
 Future Plan
 Conclusion

3.  Piezoelectric are a class of materials that can
transfer mechanical energy into electrical and vice
versa
 Ceramics like PZT have excellent dielectric
properties but their use is restricted
 Some of the polymers show dielectric properties
but their use is restricted

4.  Intense work has been done on development of ceramic
filled polymer matrix composite
 PVDF polymer has received largest attention
 However there is a need to find substitute for PVDF due
to its toxic effects on environment

5.  To find a suitable substitute for PVDF and PZT
composites.
 Substitute is expected to give comparable piezoelectric
and dielectric properties.
 Substitute has no or lesser hazardous effects on
environment and health.

7.  Dielectric constant increases as volume fraction of filler
increases
 Higher temperature stability can be achieved by using
modified ceramic filler

8. Fig 1 Density and relative density of PVDF BTO composite as a function of volume fraction of BTO.

9. Fig.2 Dielectric loss and dielectric constant at 1 KHz as a function of temperature.

10.  Highly aligned whiskers of BatiO3 are added instead of
its powder
 All dielectric parameters like dielectric constant
remanant polarization are high in whisker form than in
powder form

11. Fig 3 Ferroelectric hysteresis loops for 30% whisker-PVDF composite:
(a) normal and (b) parallel specimens

12. Fig 4 Profiles of: (a) powder-PVDF composite (b) parallel
specimen and (c) normal specimen.

13. Here main focus is to tailor
 Curie temperature
 Particle size
 Volume fraction.

14. Fig 5 Effect of La content (x) on Curie temperature of Pb1−x Lax(Zr0.55Ti0.45)1−x/4O3ceramics.

15. Effects of ceramic volume fraction and particle size on (a) piezoelectric coefficient
and (b) dielectric constant of a) PL0.04ZT/PVDF, (b) PL0.07ZT/PVDF composites.

16.  Not only as a product Halogen based polymers have
serious environmental issues during their synthesis as
well
 Apart from PZT and Barium Titanate deserving attention
was not given to the any other ceramic
 Considering strict environmental regulations need to find
substitution for PVDF is inevitable which should be
halogen free

17.  Low density-1.15 g.cm−3
 Thermal stability
 High strength
 Shows a dielectric constant in the range
4.5-5.5

18. The crystal structure of KNN

19.  Potassium Sodium Niobate (KNN) is lead-free
ceramic
 Piezoelectric d33coefficient typically between
80 and110 pC/N
 Dielectric constant is 200-250

20.  Lead free ceramic
 Non toxic
 Sodium and potassium carbonates are readily
available
 Good dielectric and piezoelectric properties

22. Angle 2 theta
Intensity

23.  Anode material- Cu
 K-Alpha 1 wavelength – 1.540598
 K-Alpha 2 wavelength - 1.544426
 Ratio K1/K2 - 0.5
 Generator Voltage- 40 V
 Tube Current – 30

24. Angle 2 theta
Intensity

25.  Anode material- Cu
 K-Alpha 1 wavelength – 1.540598
 K-Alpha 2 wavelength - 1.544426
 Ratio K1/K2 - 0.5
 Generator Voltage- 40 V
 Tube Current – 30

26.  BET is Brunauer Emmett Teller method determine the
total specific surface area in m2/g
 Uses concept of adsorption of gas molecules on
a solid surface
 Based on the amount of gas absorbed at a given
pressure, the BET equation is used to calculate the
number of adsorbed gas molecules that would be
required to form a mono layer on the surface.

 With knowledge of the cross section area of the gas
molecules adsorbed, the surface area can be easily
calculated.

27. SR NO Component Weight of
empty tube
(gm)
Weight with
component
(gm)
1 K2CO3 24.6005 26.5864
2 Na2CO3 24.2540 26.2264
Surface Area of Na2CO3= 3.01 m2/g.
Surface Area of K2CO3= 3.54 m2/g

29.  (Na2CO3) and (K2CO3) heated at 2000 C for 2 hours to
remove moisture.
 Milling is done in jar mill for 3-4 hours of mixture of
(Na2CO3), (K2CO3) and (Nb2O5).
 Calcinations of above mixture at 8500 C- 9500 C for 4
hours in F/C

30. Sr No. Component Molecular Weight
1 Sodium Carbonate (Na2CO3) 106
2 Potassium Carbonate ( K2CO3) 138
3 Niobium Pentoxide ( Nb2O5) 266
4 Potassium Sodium Niobate[( K.5 Na.5)NbO3] 172
5 Carbon Dioxide(CO2) 44
REACTION:
 1(Na2CO3) +1(K2CO3)+2 (Nb2O5) 4 [( K.5 Na.5)NbO3] +2(CO2)
 Now 1 mole of [(K.5 Na.5)NbO3] = 172 gram
By above reaction balancing we note that to produce 1 mole of KNN we require 0.25 moles
each of (Na2CO3) and (K2CO3) and .5 mole of (Nb2O5)
0.25 mole of (Na2CO3) =26.5 g
0.25 mole of ( K2CO3) =34.5g
0.5 mole of ( Nb2O5) =133g

31. i.e 25/172=0 .1453 mole
 Mole of (Na2CO3) = .1453/4 = 0.0363 mole = 3.8478g
… … I
 Mole of ( K2CO3) = .1453/4 =0 .0363 mole = 5.0094g …
… … II
 Mole of ( Nb2O5) = .1453/2 = 0.07265 mole =19.3249g …
… … III
Amount of CO2 evolved = (I+II+III)- 25g of KNN=28.1821-
25= 3.1821g=0.0723 mole

32.  X-Ray Diffraction (XRD)
 A Scanning Electron Microscope (SEM)

33. It can be processed by processing techniques like:-
 Hot Pressing
 Compression Moulding
 Film Casting

34.  Thermo gravimetric analysis (TGA)
 X-ray diffraction (XRD)
 Scanning electron microscope (SEM)
 BET for surface area analysis.
 Impedance spectroscopy is used to dielectric properties.

35.  Substitution for halogen based polymers and lead based
ceramics is feasible
 There are different parameters must be considered
during composite fabrication
 PAN matrix composite having ceramic named KNN as
filler is to be fabricated
 It is expected to give comparable properties with less or
no hazardous effect on environment

36.  [1] Fundamentals of Materials Science and Engineering
- By William Callister
 [2] Wikipedia- free encyclopedia
 [3] Piezoelectric properties of cement based/PVDF/PZT
composites
 [4] Preparation and properties of polymer matrix piezoelectric
composites containing aligned BaTiO3 whiskers.
 [5] Highly enhanced piezoelectric properties of PLZT/PVDF
composite by tailoring the ceramic Curie temperature, particle
size and volume fraction.
 [6] Microstructural, structural, dielectric and piezoelectric
properties of potassium sodium niobate thick films.