Temperature influencing amplitude of resonating carbonblack nanoparticles in an RTV615 elastomer'

1
Temperature influencing amplitude of resonating
carbon-black nanoparticles in an RTV-615
elastomer.

• Jared Durden
• Drury University
• Advisor Adam Huang

2
Silicone polymer chemical vapor sensors
fabricated by direct polymer pattering on
substrate technique

• The preparation of the composite
• Acetylene based carbon black nanoparticles (from
  Alfa Aesar, 40 nm mean diameter)is mixed with
  RTV-615 silicone.
• The RTV-615 is first mixed with its curing agent
  with a 101 ratio.
• The nanoparticles are mixed with the silicone
  followed by a 10 min degas step at 13 Pa
  (100mTorr).
• In all the test samples the RTV615 to carbon
  black mass ratio of 10.2 is used (yielding a
  resistivity of 110-
• cm).

ASEM micrograph showing the 4X4RTV-11
silicone/carbon black composite chemical vapor
sensor arrays occupying an area of 560 m560 m
on a glass substrate.
3
The Phenomena

• Resonance remains constant in the material untill
  a particular temperature window is reached
• From approximately 60 to 65 degrees Celcius we
  see a peak in amplitude 100 times greater than
  the average resonance amplitude
• What is the cause?

4
Elastomers

• Agrogates of nanoparticles-
• Agrogates modeled as single particle.

5
My first models
6
New Model of elastomer/particle interaction
Assuming particle diameter of 20nm, polymer
chain thickness of 1nm diameter, and
interparticle distance of 60 nm.
7
Properties of elastomer

• Crystallization is increased by stress/strain
  applied to elastomer
• Previous work show a spike in crystallization at
  a temp window between -40 and -20 degrees
  celcius.

• The creep deformation and creep rate shows a
  dependence on temperature and stress level
  suggesting a thermally and stress activated
  process.
• Both the parameters were
• decreased to different extents by the addition of
  nanofillers.

8
My Hypotheses

• The increased amplitude is due to the natural
  resonance of the elastomer which is a mechanical
  agitation caused by the temperature windows
  effect on the crystallization of the polymer
  allowing for an ideal change in the flow of
  current.

9
Isolation of VariablesExperimentally
10
Properties of Elastomers

• 5 Different elastomers to assure 5 Different Data
  points allowing optimal analysis
• Elastomers vary in Density, Elasticity (i.e.
  stress strain ration, k)
• If crystallization of elastomer molecular chains
  is responsible for resonance excitation these
  variables will give a change in temp. window,
  factor of amplitude increase

11
Isolating nano-particles influence

• 5 different percentages of filler to elastomer-
  5, 10,12,15, 20,
• Metallic particles used as filler this will help
  in determining the importance of the
  semi-conductive properties of carbon.

12
Circuit analysis

• Vary electrodes?
• Variation in potential difference of electrodes,
  rate of change, and resistance in circuit.
• Analyze resonance in different elastomers not
  only peak but natural resonance of circuit before
  and after.

13
Refrences

• Jing-Lei Yang a, Zhong Zhang a,b, Alois K.
  Schlarb a, Klaus Friedrich a
• On the characterization of tensile creep
  resistance of polyamide 66
• nanocomposites. Part I. Experimental results and
  general discussions. Polymer 2006472791-801

14
Refrences cont.

• Cornelius O. Horgan, Giuseppe Saccomandi. A
  Molecular-Statistical Basis for the Gent
  Constitutive Model of Rubber Elasticity. Journal
  of Elasticity68167-1762002
• Zhong Zhang,Jing-Lei Yang,Klaus Friedrich. Creep
  resistant polymeric nanocomposites. Polymer
  453481-34852004
• Boyce,M.C., Arruda,E.M. Constitutive Models of
  Rubber Elasticity A Review. Rubber Chemistry and
  Technolgy 73504-5232000.
• Renata Melamud,a Bongsang Kim, Saurabh A.
  Chandorkar, Matthew A. Hopcroft,
• Manu Agarwal, Chandra M. Jha, and Thomas
  W. Kenny. Temperature-compensated high-stability
  silicon. APPLIED PHYSICS LETTERS 90, 244107 2007
  resonators.

Dongsheng Liu, D. Q. Cao, Charles H.-T. Wang
-Computational Cosserat Dynamics in MEMS
Component Modelling. Tsinghua University Press
Springer-Verlag Sept. 5-102004.