Liquid Crystal Ordering in Densely Packed Colloidal Suspensions of Highly Anisotropic Monolayer Nanosheets
Year: 2024
Type: article
Abstract: Monolayer nanosheets of zirconium phosphate in aqueous suspension exhibit short-range repulsion and long-range attraction, producing, at overall volume fractions larger than about half a percent, phase separation into higher-concentration liquid crystal and lower-concentration isotropic regions. At high concentrations, this phase separation takes the form of an emulsion of condensed, liquid-crystalline droplets, which anneal to form lens-shaped tactoids. These tactoids provide an opportunity to study the liquid crystal ordering of inorganic nanosheets in the limit of large shape anisotropy (diameter/thickness~400) and high packing fraction (volume fraction ≳ 70%). The internal liquid crystal structure of the tactoids remains nematic even under conditions that would usually favor ordering into lamellar smectics. Local lamellar ordering is suggested by short-range, smectic-like layer correlations, but a full transition into a smectic phase appears to be inhibited by the nanosheet edges, which act as a perturbative population of dislocation loops in the system of layers. Under conditions of thermal equilibrium, the nanoplates organize positionally to enable bend deformation of the director, a hallmark of the nematic phase and its principal distinction from the smectic, where bend must be expelled.
Source: Crystals
Institutions: University of Colorado Boulder, Texas A&M University
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,955
Awards: G1433346967, G1821513860, Soft Materials Research Center, G3078429399, G319283152, FERROMAGNETIC LIQUID CRYSTAL COLLOIDS IN MICROGRAVITY NASA'S PHYSICAL SCIENCES RESEARCH PROGRAM CONDUCTS FUNDAMENTAL AND APPLIED PHYSICAL SCIENCES RESEARCH WITH THE OBJECTIVE OF ENABLING IMPROVED SPACE SYSTEMS AND TECHNOLOGICAL ADVANCES THAT SUPPORT NEW PRODUCTS AND OTHER BENEFITS ON EARTH. NASA'S EXPERIMENTS IN THE VARIOUS DISCIPLINES OF PHYSICAL SCIENCE REVEAL HOW PHYSICAL SYSTEMS RESPOND TO THE NEAR ABSENCE OF GRAVITY. THEY ALSO REVEAL HOW OTHER FORCES THAT ON EARTH ARE SMALL AS COMPARED TO GRAVITY CAN DOMINATE SYSTEM BEHAVIOR IN SPACE. AS PART OF THESE RESEARCH EFFORTS THIS NRA SOLICITS MATERIALS SCIENCE RESEARCH PROPOSALS TO DEFINE AND DESIGN BROADLY SCOPED INVESTIGATIONS TO BE CONDUCTED ABOARD THE INTERNATIONAL SPACE STATION. THE RESEARCH WILL BE CONDUCTED AS PART OF THE PROGRAMS NEW OPEN SCIENCE INITIATIVE WHICH WAS REALIZED THROUGH THE MATERIALSLAB COMBUSTIONLAB AND FLUIDSLAB WORKSHOPS HELD IN 2014. THE MOTIVATION OF THE OPEN SCIENCE METHOD IS TO PROVIDE MASS DISSEMINATION OF THE ISS DATA TO NUMEROUS INVESTIGATORS OR USERS FROM THE GOVERNMENT ACADEMIA AND INDUSTRY FROM AROUND THE WORLD. THE OPEN SCIENCE METHOD BEING ADOPTED BY NASA'S PHYSICAL SCIENCES RESEARCH PROGRAM IS ILLUSTRATED IN FIGURE 1. THIS NRA FOCUSES ON OPEN SCIENCE CAMPAIGNS AS SHOWN ON THE RIGHT SIDE OF FIGURE 1. OPEN SCIENCE CAMPAIGNS UTILIZE SCIENCE DEFINITION TEAMS TO DEFINE HIGH-CONTENT EXPERIMENTS TO BE CONDUCTED ON THE ISS THAT EXPLORE A BROADER RANGE OF QUESTIONS AND GATHER MORE DATA THAN WOULD BE DONE UNDER TRADITIONAL SINGLE-PI INVESTIGATIONS. AFTER THE DATA HAS BEEN GATHERED ON THE ISS THE SCIENCE DEFINITION TEAMS WILL ANALYZE THE DATA AND PROVIDE IT TO THE NASA PHYSICAL SCIENCES INFORMATICS SYSTEM (HTTP://PSI.NASA.GOV) WHICH WILL MAKE THE DATA ACCESSIBLE TO THE GLOBAL COMMUNITY. THIS APPROACH LEVERAGES RAW AND ANALYZED DATA FROM COMPLETED EXPERIMENTS CONDUCTED AS PART OF OPEN SCIENCE CAMPAIGNS (TOP RIGHT IN FIGURE 1) AND AS PART OF TRADITIONAL PROGRAMS (TOP LEFT OF FIGURE 1) AND INCORPORATES NUMERICAL MODELS AND RELATED PUBLICATIONS TO CREATE EXPERIMENTAL INFORMATICS LIBRARIES. BY BUILDING UPON THE PREVIOUS INVESTIGATORS FINDINGS RESEARCH ADVANCES CAN BE ACCELERATED THROUGH INFORMATICS TURNING INFORMATION INTO KNOWLEDGE LEADING TO NEW DISCOVERIES WITHIN A FEW YEARS VERSUS MULTIPLE DECADES. PROVIDING GREATER ACCESS TO THIS DATA WILL ALSO ALLOW FOR NOVEL AND UNIQUE ANALYSIS TO BE PERFORMED THAT WILL CONTRIBUTE TO NEW RESEARCH OPPORTUNITIES AND TRANSLATE RESULTS FROM FUNDAMENTAL SCIENCE TO APPLIED SCIENCE WITH THE GOAL OF PRODUCING NEW PRODUCTS FOR THE MARKETPLACE., Soft Materials Research Center, THE CENTRAL OBJECTIVES OF THE PROPOSED THE RESEARCH ARE TO INVESTIGATE THE DYNAMICS OF PHASE TRANSITIONS , INCLUDING THE FORMATION OF LIQUID CRYSTALS, Phase Transitions in Colloidal Suspensions of Disks, G7749454669, G961144504
OpenAlex ID: W4404111936