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Polymer sample preparation techniques

Sputter coating

A sputter coater may be purchased that deposits single layers of gold, gold-palladium, tungsten, chromium, platinum, titanium, or other metals in a very controlled thickness pattern. It is possible, and desirable, to coat only a few nm’s of metal onto the sample surface.

Spin coating

Many polymer films are depositing via a spin coater which spins a substrate (often ITO glass) and drops of polymer liquid are dispersed an even thickness on top of the substrate.

Staining

Another option for polymer sample preparation is staining the sample. Stains act in different ways, but typical stains for polymers are osmium tetroxide (OsO 4 ), ruthenium tetroxide (RuO 4 ) phosphotungstic acid (H 3 PW 12 O 40 ), hydrazine (N 2 H 4 ), and silver sulfide (Ag 2 S).

Examples

Comb-block copolymer (microstructure of cast film)

  • Cast polymer film (see [link] ).
  • To view interior structure, the film was cut with a microtome or razor blade after the film was frozen in liquid N 2 and fractured.
  • Stained with RuO 4 vapor (after cutting).
  • Structure measurements were averaged over a minimum of 25 measurements.
SEM micrograph of comb block copolymer showing spherical morphology and long range order. Adapted from M. B. Runge and N. B. Bowden, J. Am. Chem. Soc. , 2007, 129 , 10551. Copyright: American Chemical Society (2007).

Polystyrene-polylactide bottlebrush copolymers (lamellar spacing)

  • Pressed polymer samples into disks and annealed for 16 h at 170 °C.
  • To determine ordered morphologies, the disk was fractured (see [link] ).
  • Used SEM to verify lamellar spacing from USAXS.
SEM image of a fractured piece of polymer SL-1. Adapted from J. Rzayev, Macromolecules , 2009, 42 , 2135. Copyright: American Chemical Society (2009).

Swnts in ultrahigh molecular weight polyethylene

  • Dispersed SWNTs in interactive polymer.
  • Samples were sputter-coated in gold to enhance contrast.
  • The films were solution-crystallized and the cross-section was imaged.
  • Environmental SEM (ESEM) was used to show morphologies of composite materials.
  • WD = 7 mm.
  • Study was conducted to image sample before and after drawing of film.
  • Images confirmed the uniform distribution of SWNT in PE ( [link] ).
  • M W = 10,000 Dalton.
  • Study performed to compare transparency before and after UV irradiation.
SEM images of crystallized SWNT-UHMWPE films before (left) and after (right) drawing at 120 °C. Adapted from Q. Zhang, D. R. Lippits, and S. Rastogi, Macromolecules , 2006, 39 , 658. Copyright: American Chemical Society (2006).

Nanostructures in conjugated polymers (nanoporous films)

  • Polymer and NP were processed into thin films and heated to crosslink.
  • SEM was used to characterize morphology and crystalline structure ( [link] ).
  • SEM was used to determine porosity and pore size.
  • Magnified orders of 200 nm - 1 μm.
  • WD = 8 mm.
  • M W = 23,000 Daltons
  • Sample prep: spin coating a solution of poly-(thiophene ester) with copper NPs suspended on to ITO coated glass slides. Ziess, Supra 35
SEM images of thermocleaved film loaded with nanoparticles with scale bar 1 μm. Adapted from J. W. Andreasen, M. Jorgensen, and F. C. Krebs, Macromolecules , 2007, 40 , 7758. Copyright: American Chemical Society (2007).

Cryo-sem colloid polystyrene latex particles (fracture patterns)

  • Used cryogenic SEM (cryo-SEM) to visualize the microstructure of particles ( [link] ).
  • Particles were immobilized by fast-freezing in liquid N 2 at –196 °C.
  • Sample is fractured (-196 °C) to expose cross section.
  • 3 nm sputter coated with platinum.
  • Shapes of the nanoparticles after fracture were evaluated as a function of crosslink density.
Cryo-SEM images of plastically drawn polystyrene and latex particles. Adapted from H. Ge, C. L. Zhao, S. Porzio, L. Zhuo, H. T. Davis, and L. E. Scriven, Macromolecules , 2006, 39 , 5531. Copyright: American Chemical Society (2006).

Bibliography

  • H. Ge, C. L. Zhao, S. Porzio, L. Zhuo, H. T. Davis, and L. E. Scriven, Macromolecules , 2006, 39 , 5531.
  • J. Rzayev, Macromolecules , 2009, 42 , 2135.
  • J. W. Andreasen, M. Jorgensen, and F. C. Krebs, Macromolecules , 2007, 40 , 7758.
  • M. B. Runge and N. B. Bowden, J. Am. Chem. Soc. , 2007, 129 , 10551.
  • P. J. Goodhew, J. Humphreys, and R. Beanland, Electron Microscopy and Analysis , Taylor&Francis Inc., New York (2001).
  • Q. Zhang, D. R. Lippits, and S. Rastogi, Macromolecules , 2006, 39 , 658.

Questions & Answers

Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
hi
Loga
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
advantages of NAA
Sai Reply
how I can reaction of mercury?
Sham Reply

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Source:  OpenStax, Physical methods in chemistry and nano science. OpenStax CNX. May 05, 2015 Download for free at http://legacy.cnx.org/content/col10699/1.21
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