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Title: Manipulating the ABCs of self-assembly via low-χ block polymer design

Block polymer self-assembly typically translates molecular chain connectivity into mesoscale structure by exploiting incompatible blocks with large interaction parameters (χ ij). In this report, we demonstrate that the converse approach, encoding low-χ interactions in ABC bottlebrush triblock terpolymers (χ AC ≲ 0), promotes organization into a unique mixed-domain lamellar morphology which we designate LAM P. Transmission electron microscopy indicates that LAMP exhibits ACBC domain connectivity, in contrast to conventional three-domain lamellae (LAM 3) with ABCB periods. Complementary small angle X-ray scattering experiments reveal a strongly decreasing domain spacing with increasing total molar mass. Self-consistent field theory reinforces these observations and predicts that LAM P is thermodynamically stable below a critical χ AC, above which LAM 3 emerges. Both experiments and theory expose close analogies to ABA triblock copolymer phase behavior, collectively suggesting that low-χ interactions between chemically similar or distinct blocks intimately influence self-assembly. Furthermore, these conclusions provide new opportunities in block polymer design with potential consequences spanning all self-assembling soft materials.
 [1] ; ORCiD logo [2] ;  [3] ;  [4] ;  [4] ; ORCiD logo [5] ;  [5] ; ORCiD logo [1]
  1. California Institute of Technology, Pasadena, CA (United States)
  2. Univ. of California, Santa Barbara, CA (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. California Inst. of Technology (CalTech), Pasadena, CA (United States)
  5. Univ. of Waterloo, Waterloo, ON (Canada)
Publication Date:
Grant/Contract Number:
Published Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 114; Journal Issue: 25; Journal ID: ISSN 0027-8424
National Academy of Sciences, Washington, DC (United States)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
National Science Foundation (NSF); U.S. Department of Defense (DOD); USDOE Office of Science (SC)
Country of Publication:
United States
36 MATERIALS SCIENCE; LAMP; block polymer; domain spacing; polymer nanostructure; self-assembly
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1373730