The morphology of symmetric diblock copolymers as revealed by neutron reflectivity

Journal Article · Tue May 01 00:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.458499· OSTI ID:6947153

Anastasiadis, S H; Russell, T P ^[1]; Satija, S K; Majkrzak, C F ^[2]

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1. IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120-6099 (USA)
2. National Institute of Standards and Technology, Reactor Radiation Division, Gaithersburg, Maryland 20899 (USA)

The specular reflectivity of neutrons has been used to characterize quantitatively the microphase separated morphology of symmetric, diblock copolymers of polystyrene (PS), and polymethylmethacrylate (PMMA), as a function of the total molecular weight of the copolymer where either block is perdeuterated. It is shown that the hyperbolic tangent function, as opposed to a linear or cosine-squared function, most closely describes the concentration gradient at the interface between the lamellar copolymer microdomains. The effective width of the interface is found to be independent of the molecular weight of the copolymer blocks and has a value of 50{plus minus}3 A. This interface is also found to be identical to that between PS and PMMA, homopolymers. However, using measured values of the Flory--Huggins interaction parameter for PS and PMMA, current theoretical treatments cannot describe the observed widths of the interface.

• DOE Contract Number: FG03-88ER45375
• OSTI ID: 6947153
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 92:9; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
COHERENT SCATTERING
COPOLYMERS
DIFFRACTION
DOMAIN STRUCTURE
ESTERS
INTERFACES
MATERIALS
MOLECULAR WEIGHT
MORPHOLOGY
NEUTRON DIFFRACTION
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHYSICAL PROPERTIES
PLASTICS
PMMA
POLYACRYLATES
POLYMERS
POLYOLEFINS
POLYSTYRENE
POLYVINYLS
REFLECTIVITY
SCATTERING
SURFACE PROPERTIES
SYNTHETIC MATERIALS