CHEMISTRY

Nematic-to-columnar mesophasetransition by in situsupramolecular polymerizationKeiichi Yano1, Yoshimitsu Itoh1*, Fumito Araoka2, Go Watanabe3,Takaaki Hikima4, Takuzo Aida1,2*

Disk- and rod-shaped molecules are incompatible in coassembly, as the former tend tostack one-dimensionally whereas the latter tend to align in parallel. Because this typeof incompatibility can be more pronounced in condensed phases, different-shapedmolecules generally exclude one another. We report that supramolecular polymerizationof a disk-shaped chiral monomer in nematic liquid crystals comprising rod-shapedmolecules results in order-increasing mesophase transition into a single mesophasewith a core-shell columnar geometry. This liquid crystalline material responds quicklyto an applied electric field, resulting in unidirectional columnar ordering. Moreover,it can be modularly customized to be optoelectrically responsive simply by using aphotoisomerizable rod-shaped module. The modular strategy allows for cooperativeintegration of different functions into elaborate dynamic architectures.

Polymerization in organized media hasattracted attention because of the poten-tial of themedia to promote higher-orderstructures and the resulting physical prop-erties (1–5). Conversely, supramolecular

polymerization (6–8) in organized media hasbeen explored very little to date (9, 10), becausethe resultant noncovalent structures (if any)conferred by the media cannot be isolated.We focused on supramolecular polymeriza-

tion in liquid crystalline (LC) media (Fig. 1A). Ifthe affinity between the resulting supramolec-ular polymer and the LC medium is large, thenthey are miscible, affording a uniform LC dis-persion of the polymer (Fig. 1A, b). Conversely,if their affinity is poor, the polymer moleculesare bundled and phase-separated from the LCmedium (Fig. 1A, d). In the latter case, the in-soluble polymer bundlesmay form a cross-linkedthree-dimensional network, which possibly com-partmentalizes the LC phase and enhances itsdynamic properties, as seen with LC physicalgels (9). We find that supramolecular polymer-ization in nematic LCmedia induces an order-increasing mesophase transition (Fig. 1A, c),allowing highly elaborate, core-shell columnarcoassembly.Our initialmotivationwas to investigatewheth-

er a chiral dopant, if supramolecularly polym-erized into a helical strand, could geometricallytwist anematicmesophase into a cholestericmeso-

phase to a greater extent than itsmonomeric formcould (11). For this purpose, we chose a chiralbenzenetricarboxamide (BTA) analog (12) as asupramolecularly polymerizable chiral dopantwhose polymerization in solution has been in-vestigated by Meijer and co-workers (7, 13).In general, different-shaped molecules, such

as rods and disks, tend to exclude one anotherdespite the large entropic penalty of the resultingphase separation (14). The combination of OCBRod,a rod-shaped LC molecule affording a nematicorder (Fig. 1C), and a BTA derivative monomersuch as C10DiskNH* (Fig. 1B, left) is not an excep-tion to this general tendency. C10DiskNH*, whichcarries three chiral hydrocarbon side chains,noncovalently polymerizes via triple hydrogen-bonding (H-bonding) interactions at its amidegroups. We heated a mixture of C10DiskNH* andOCBRod (C10DiskNH*/

OCBRod ratio = 1/30) (figs.S13B, S17C, and S21C) and then allowed the re-sulting isotropic melt to cool so that C10DiskNH*could polymerize noncovalently in the LCmediumof OCBRod. Polarized optical microscopy (POM)revealed bundled fibers thatwere phase-separatedfrom the LC medium (fig. S14, A and C). To ad-dress this incompatibility issue, we synthesizedOCBDiskNH* (Fig. 1B, center, and figs. S15A andS32) (12), whose hydrocarbon side chains areappended with an oxycyanobiphenyl (OCB) ter-minus as a potential compatibilizer with OCBRod(15, 16). A mixture of OCBDiskNH* and

OCBRod(molar ratio, 1/30), treated thermally in a sim-ilar fashion, showed a fan-shaped POM texture(fig. S14, B and D) characteristic of columnarLC phases rather than cholesteric LC phases.Figure 1D shows a full phase diagram of theOCBDiskNH*-

OCBRod system, where a columnarmesophase at an OCBDiskNH*/

OCBRodmolar ratioof 1/6 develops entirely as a single mesophaseover the temperature range from 117 to –6°C(Fig. 2D and fig. S11E). When this mixture was

dilutedwith OCBRod, an exothermic peak assign-able to its isotropic-to-nematic phase transitionappeared at ~68°C, indicating that excess OCBRodphase-separated (figs. S12 and S24). UnlikeOCBDiskNH* and

OCBRod alone (figs. S11, S16,and S19), OCBDiskNH*-

OCBRod (molar ratio, 1/6)in its synchrotron x-ray diffraction (XRD) pro-file at 100°C presented sharp and intense peaksin a low-angle region, whereas the wide-angleregion presented only a broad diffraction peakwith a d-spacing of 3.4 Å (Fig. 2G).We confirmedthat this columnar LCmaterial adopts a centeredrectangular c2mm symmetry (lattice parameters,a = 75.2 Å; b = 35.0 Å), where each column con-tains tilted p-stacks of polymeric OCBDiskNH* inits core (17), which is wrapped by a polymericshell comprising self-assembled OCBRod (Fig. 2A).Molecular dynamics (MD) simulations (12) alsoindicated the possibility of the formation of acore-shell columnar structure from OCBDiskNH*and OCBRod (figs. S54 to S57 and S60). Uponbeing cooled from 100 to 60°C, this columnarLC material changed its fundamental geometryfrom rectangular to hexagonal (a = 40.8 Å) with-out an exotherm (figs. S11E and S20). This phasesequence is opposite to those commonly observed(18) and has been observed in only rare cases (19).Fourier-transform infrared (FTIR) spectros-

copy (figs. S30A and S31) of an isotropic state ofOCBDiskNH*-

OCBRod (molar ratio, 1/6) showedstretching vibrations due to free amide C=O andN–Hmoieties at 1673 and 3401 cm–1, respectively(13). When this isotropic mixture was cooled to100°C, allowing the phase transition into thecolumnar LC phase, these vibrational bandsshifted abruptly to the lower wave numbers of1640 and 3243 cm–1, respectively, indicating thatthe amide moieties of OCBDiskNH* H-bonded toform its supramolecular polymer. The supramo-lecular polymerization of OCBDiskNH* is essentialfor the mesophase to adopt a columnar geom-etry. Chiral OCBDiskNMe* (Fig. 1B, right, and figs.S13D, S15C, and S22), which is an N-methylatedversion of OCBDiskNH*, cannot form a H-bondedsupramolecular polymer. This modified version,when doped into the nematic phase of OCBRod(OCBDiskNMe*/

OCBRod ratio = 1/6), gave rise tothe formation of only a cholesteric mesophase(Fig. 2, C, F, and I) and did not induce thenematic-to-columnar mesophase transition.As described above, chiral OCBDiskNH* carries

a stereogenic center in each of its side chains thatis in proximity to theH-bonding amide unit (Fig.1B, center). We confirmed that the supramolec-ular polymers of (R)-OCBDiskNH (OCBDiskNH

R) and(S)-OCBDiskNH (OCBDiskNH

S) inmethylcyclohexanewere optically active and presented circulardichroism (CD) spectra that are mirror images(figs. S28A and S34). Heating to 80°C or mix-ing with 5 volume % methanol allowed thesupramolecular polymers to depolymerize, andtheir characteristic CD bands virtually disap-peared (fig. S28B). We also found that poly-meric OCBDiskNH

R in the columnarmesophase ofOCBDiskNH

R-OCBRod (molar ratio, 1/6) at 100°Cadopts a helical geometry, displaying a distinctchiroptical feature (Fig. 2J, red, and fig. S29C).

RESEARCH

Yano et al., Science 363, 161–165 (2019) 11 January 2019 1 of 5

1Department of Chemistry and Biotechnology, School ofEngineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku,Tokyo 113-8656, Japan. 2RIKEN Center for Emergent MatterScience, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.3Department of Physics, School of Science, KitasatoUniversity, 1-15-1 Kitasato, Minami-ku, Sagamihara,Kanagawa 252-0373, Japan. 4RIKEN SPring-8 Center, 1-1-1Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.*Corresponding author. Email: itoh@macro.t.u-tokyo.ac.jp (Y.I.);aida@macro.t.u-tokyo.ac.jp (T.A.)

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TheMD simulation of OCBDiskNH*-OCBRod (molar

ratio, 1/6) again indicated the formation of ahelical BTA assembly in the core (fig. S58).As expected, when the opposite enantiomerOCBDiskNH

Swas coassembled with OCBRod (molarratio, 1/6), the resultant CD spectrumwas amirrorimage of that observed for OCBDiskNH

R-OCBRod(Fig. 2J, blue, and fig. S29E). Upon heating to160°C to induce the phase transition into itsisotropic melt, OCBDiskNH*-

OCBRod became vir-tually CD silent (fig. S29A).Columnar LC phases are known to be rigid and

poorly responsive to electrical stimuli (20–22).We introduced OCBDiskNH*-

OCBRod (molar ratio,1/6) into a comb-type electrical cell, enabling in-plane application of the electric field (E-field)(Fig. 3A) (12). Before the application of the E-field,the sample at 100°C in POMwas birefringent anddisplayed a fan texture characteristic of randomlyorientedmultidomain columnar LC phases. Thetwo-dimensional (2D)–XRD pattern, obtained byirradiation with an x-ray beam along the z axis ofthe sample (Fig. 3A), was isotropic with a con-centric diffraction feature (fig. S46A). However,when a direct-current (DC) E-field (40 V mm–1)was applied to this sample along the arrow shownin Fig. 3A, the fan texture disappeared within 1 s(fig. S36 and movie S1). Upon being rotatedaround the z axis, the resultingmaterial in POMshowed bright- and dark-field images alternatelyat 45° intervals (fig. S35, A and B), indicating thatthe LC columns uniformly align unidirectionallyfor up to several hundred micrometers. In 2D-XRD, this oriented sample showed two distinctdiffraction arcs, indexed to the (200) and (400)planes of the rectangular geometry, only in theequatorial direction (Fig. 3C), indicating parallelorientation of the core-shell columns relative tothe direction of the applied DC E-field. The orderparameter of the columnar orientation, as de-termined by scattering intensity plots, was 0.91(fig. S47A). The observed response time of thecolumnar LC sample in its electrical orientationwas shorter than most reported (table S1). De-spite the rapid response of OCBDiskNH*-

OCBRod,the unidirectional order remained unchangedfor several days at 100°C after the E-field wasturned off. This slow structural relaxation is notexpected for the parent nematic LC material ofOCBRod. In polarized FTIR spectroscopy at 100°C,this unidirectional order presented a dichroicfeature (Fig. 3D and fig. S51), where the polarplots of the H-bonded amide N–H (3239 cm–1)and C≡N (2224 cm–1) groups showed their ab-sorption maxima in the meridional and equa-torial directions, respectively. Together with the2D-XRD profiles (Fig. 3C), the FTIR results makeit apparent that the amide N–H and C≡N groupspreferentially align parallel and perpendicularto the columnar axis, respectively, in accordancewith the MD simulation (fig. S59). By switchingthe applied E-field from DC to AC (alternatingcurrent) (10 kHz, 24 V mm–1), the columnar direc-tionwas changed fromparallel to perpendicularand vice versa relative to the direction of theapplied E-field (Fig. 3, B, E, and F; figs. S37 toS39; and movie S2). Such frequency-dependent

behavior is reasonable considering that the C≡NandH-bonded amide groups, which are arrangedorthogonally to each other in the LC column, tendto align parallel to the appliedAC andDCE-fields,respectively (22). The orientational change profile,obtained from the scattering intensity–azimuthalangle (q) plots, showed that two peaks (q =0° and

180°; perpendicular orientation) emerged at theexpense of the original peaks (q = ±90°; parallelorientation) (figs. S48 and S49). Thus, the orien-tational change of OCBDiskNH*-

OCBRod occurredthrough electrical reconstruction, that is, electricaldisassembly and subsequent reassembly (Fig. 3G),rather than rotation of the core-shell columns. The

Yano et al., Science 363, 161–165 (2019) 11 January 2019 2 of 5

Fig. 1. Phase transition of LC media by supramolecular polymerization. (A) Schematicrepresentations of possible modes of supramolecular polymerization in LC media. A monomercan form its one-dimensional supramolecular polymer in a nematic LC medium. (a to d) Dependingon the affinity between the monomer or the resultant supramolecular polymer and the LC medium,four different modes are expected. (B) Molecular structures of disk-shaped chiral monomersderived from BTA: C10DiskNH*,

OCBDiskNH*, andOCBDiskNMe*. Me, methyl. (C) Molecular structures

of rod-shaped LC molecules affording a nematic order: OCBRod and AZORod. Upon trans-cisisomerization, AZORod undergoes a reversible phase transition between its nematic LC phase andisotropic liquid. Vis, visible. (D) Phase diagram of OCBDiskNH*-

OCBRod. Iso, SC, Colr, Colh, Col, Ch, N,and Cr denote isotropic, soft crystalline, rectangular columnar, hexagonal columnar, columnar(unidentified), cholesteric, nematic, and crystalline phases, respectively.

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possible energy diagram is shown in Fig. 3G, a,where the intermediate state, featuring dis-sociated OCBDiskNH* and

OCBRod, substantiallylowers the energetic barrier for the electricalreconstruction. Such anM-shaped energy diagram

is not expected when the core and shell parts ofthe column are covalently connected (Fig. 3G, b).In general, high levels of structural integrity

and stimulus responsiveness aremutually exclu-sive. However, Zhang et al. recently succeeded in

addressing this issue by integrating a proteincrystal into a polymer network (23). In this work,we showed that a rod (OCBRod), when combinedwith a disk (OCBDiskNH*), properly operates forachieving the high levels of structural integrityand stimulus responsiveness. Furthermore, asdescribed below, our material is customizableby modifying the rod- and disk-shaped compo-nents. An example made use of photoisomeriz-able AZORod (Fig. 1C), instead of OCBRod, for thecoassembly with OCBDiskNH*, which resulted inthe formation of a core-shell columnarmesophasewith a rectangular geometry (Fig. 2, B, E, and H,and fig. S23), similar to the case of OCBDiskNH*-OCBRod. The isotropic-to-columnar phase transi-tion, whichwas observed for OCBDiskNH*-

AZORod(molar ratio, 1/6) at 155°C (fig. S11G), was ac-companied by the H-bonding–mediated supra-molecular polymerization of OCBDiskNH* (figs.S30B and S33, A to C). The columnar LC mate-rial of OCBDiskNH*-

AZORod was optically active,displaying distinct CD bands at 320 and 370 nm(Fig. 2K) originating from the OCB moietiesin OCBDiskNH* [wavelength of maximum ab-sorption (lmax) = 300 nm] and AZORod (lmax =347 nm), respectively (fig. S25B). Thus, notonly the core but also the shell in the core-shellcolumnar assembly adopts a helical geometrywith a complementary helical handedness (Fig.2B). Just like OCBDiskNH*-

OCBRod, OCBDiskNH*-AZORod was electrically alignable (figs. S40 andS50). Furthermore, it was optically responsive(24): The LC material, upon exposure to 365-nmultraviolet (UV) light in a sandwich-type glasscell at 140°C (Fig. 4A) (12), underwent a phasetransition into an isotropic melt, where thephotoirradiated portion changed its appearancefrom birefringent to dark (Fig. 4C, f and g). Asshown in movie S3, this reversible change oc-curred within seconds upon turning the UVlight irradiation off and on (fig. S41). We foundthat this phase transition is due to the depoly-merization of columnarly assembled OCBDiskNH*accompanied by the trans-to-cis photoisomeriza-tion of AZORod in the shell (Fig. 4B). Upon ir-radiation with UV light, OCBDiskNH*-

AZORodshowed an enhancement of its electronic absorp-tion intensity at 445 nm due to the cis form ofAZORod at the expense of the absorption in-tensity at 347 nm due to its trans form (figs. S26and S27). Concomitantly, the stretching vibra-tion due to the H-bonded amide C=O moiety(1640 cm–1) shifted to the higher wave numberof 1671 cm–1, whereas that due to the N–Hmoiety(3243 cm–1) became highly obscure (fig. S33, Dand E). The thermodynamic stability of polymericOCBDiskNH* is highly sensitive to the polarity ofthe medium. From the FTIR spectral featuresdescribed above, we believe that the dissociationof the polymeric OCBDiskNH* upon irradiationwithUV light is caused by the enhanced polarityof the medium upon photochemical generationof highly polar cis-AZORod (Fig. 4B).A wide variety of operating principles have

been reported for the realization of molecularinformation processors (25–27). As LCmaterialscan provide an amplified optical output because

Yano et al., Science 363, 161–165 (2019) 11 January 2019 3 of 5

Fig. 2. Noncovalent modular approach to hierarchically ordered core-shell columnar LC phases.(A to C) Schematic representations; (D to F) POM images under crossed polarizers; (G to I) synchrotronXRD patterns; and (J and K) CD spectra of [(A), (D), (G), and (J)] OCBDiskNH*-

OCBRod at 100°C, [(B),(E), (H), and (K)] OCBDiskNH*-

AZORod at 140°C, and [(C), (F), and (I)] OCBDiskNMe*-OCBRod at 30°C at

disk/rod molar ratios of 1/6. Supramolecular polymerization of OCBDiskNH* in (A) OCBRod and (B) AZORodresults in mesophase transition into a columnar LC phase with a core-shell geometry. Each columnbears a helical polymeric core composed of H-bonded OCBDiskNH*, which is surrounded by apolymeric shell comprising (A) OCBRod and (B) AZORod with a complementary helical handedness.(C) Nonpolymerizable OCBDiskNMe* in OCBRod forms a cholesteric LC phase. [(D) to (F)] For thePOM observations, a sandwich-type glass cell (5 mm of separation) was employed. Scale barsrepresent 100 mm. [(G) to (I)] Synchrotron XRD patterns in a capillary were obtained upon coolingfrom isotropic melts. Miller indices are given in parentheses. a.u., arbitrary units; q, scatteringvector. (Insets) Diffraction profiles in the wide-angle region. [(J) and (K)] For the CD spectroscopy,each of the samples was introduced into a sandwich-type quartz cell. The CD spectra werenormalized by the thicknesses of their quartz cells. mdeg, millidegrees.

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Yano et al., Science 363, 161–165 (2019) 11 January 2019 4 of 5

Fig. 3. Electrical reconstruction of thecore-shell columnar LC material and itsenergy diagram. (A) Schematic representationof a comb-type electrical cell comprising twoparallel glass plates (20 mm of separation) forin-plane E-field application. (B) Electrical reas-sembly of OCBDiskNH*-

OCBRod (molar ratio, 1/6),where the core-shell LC columns can be orientedparallel and perpendicular to the directionsof applied DC and AC E-fields, respectively.(C to F) [(C) and (E)] Synchrotron 2D-XRDprofiles and [(D) and (F)] polar plots of thepolarized IR absorption intensities of OCBDiskNH*-OCBRod at 100°C oriented by applying [(C) and(D)] a DC E-field (40 V mm–1) and [(E) and (F)] anAC E-field (square wave, 10 kHz, 24 V mm–1).Arel, relative absorbance. [(C) and (E)] Millerindices are given in parentheses. [(D) and (F)]Polarized IR absorption intensities, arisingfrom the H-bonded amide N–H (3239 cm–1;purple) and C≡N (2224 cm–1; orange) groups,were recorded upon rotation of the polarizer at5° intervals. These intensities were normalizedrelative to the minimum value among them.(G) Energy diagrams for the electricalreconstruction of columnar LC materials.(a) The noncovalent core-shell column bearsan intermediate state featuring disassembledcore and shell modules, whereas (b) thecovalent one does not.

Fig. 4. LC material–based optoelectricallyrewritable and logic gate operation byoptical and electrical stimuli. (A) Schematicrepresentation of a sandwich-type glass cellcomprising two parallel glass plates (5 mmof separation) for vertical E-field applicationand UV light irradiation. (B) Schematicrepresentations of the photoinduceddepolymerization and repolymerizationof OCBDiskNH*-

AZORod (molar ratio, 1/6)between the columnar LC and its isotropicliquid upon UV light irradiation (365 nm)and backward thermal relaxation. (C) POMimages of OCBDiskNH*-

AZORod (molar ratio,1/6) upon application of a power-tunedDC E-field (5 V mm–1) and/or upon irradiationwith 365-nm UV light with a lattice-patternedphotomask. Dashed squares representareas exposed to UV light, whereasthe entire area was exposed to the E-field.Scale bars represent 200 mm.

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of their long-range molecular ordering, the de-velopment of LC material–based logic gates isan interesting challenge. Such logic gates re-quire LCmaterials that can respond differently tomultiple stimuli. We developed an LCmaterial–based optoelectrically rewritable device by usingOCBDiskNH*-

AZORod (Fig. 4C), exploiting its opti-cally and electrically responsive properties. Thestrategy uses a power-tuned DC E-field that can-not solely orient the LC columns but can onlyassist the photodissociated monomer to reas-semble into a unidirectionally oriented colum-nar order. The as-received columnar LC phase ofOCBDiskNH*-

AZORod (molar ratio, 1/6) at 140°Cprovided a birefringent multidomain sample(Fig. 4C, a) in a sandwich-type glass cell (Fig.4A). This POM image could be darkened by theapplication of a DC E-field with a power above5 V mm–1; otherwise, it remained birefringent(Fig. 4C, b and c; fig. S42; and movie S4). Bycontrast, when this sample was exposed to UVlight, its POM image became nonbirefringentlydark by the photoinduced columnar-to-isotropicphase transition (Fig. 4C, f). However, when theUV irradiation ceased, the POM image becamebirefringent again because the columnar meso-phase, thus reformed, presented a randomlyoriented multidomain feature (Fig. 4C, g) anal-ogous to the initial state (Fig. 4C, a). Thus, theLC logic gate device can initialize written infor-mation by light (movie S6). Meanwhile, whenthe DC E-field application (5 V mm–1) and UVirradiation were performed simultaneously, thebirefringent image quickly turned dark withina few seconds (Fig. 4C, d and e; fig. S43; andmovie S5), becausemonomeric OCBDiskNH*, gen-erated by the photoinduced phase transition,reassembled into a unidirectionally ordered

column with the assistance of the applied DCE-field. The nonbirefringently dark image re-mained unchanged for several hours at 140°Cafter both the external inputs were turned off(fig. S44). Although this pointwise rewritable ca-pability can be realized by using photoisomeriz-able AZORod alone, the written image becameblurry because of the high fluidity of AZORod(fig. S45 andmovie S7). As shown in Fig. 4C, thewhole process can be regarded as a rewritableand logic gate because the nonbirefringently darkoutput appears only when the electrical and opti-cal inputs are applied simultaneously.

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ACKNOWLEDGMENTS

The synchrotron radiation experiments were performed on BL44B2and BL45XU at the Super Photon Ring (SPring-8) with theapproval of RIKEN (proposal nos. 20140045, 20150022, 20160024,20170046, and 20180044). The computations were performedby using the Research Center for Computational Science (Okazaki,Japan). We acknowledge K. Kato for generous support forthe synchrotron radiation experiments. Funding: This workwas financially supported by a JSPS Grant-in-Aid for ScientificResearch (S) (18H05260) on “Innovative Functional Materialsbased on Multi-Scale Interfacial Molecular Science” for T.A. Y.I.is grateful for a JSPS Grant-in-Aid for Young Scientists (A)(16H06035). K.Y. thanks the Program for Leading GraduateSchools (MERIT) and the JSPS Young Scientist Fellowship. Authorcontributions: K.Y. designed and performed all experiments.Y.I. and T.A. co-designed the experiments. K.Y., Y.I., F.A., G.W.,and T.A. analyzed the data and wrote the manuscript. G.W.performed MD simulations. T.H. supported the XRD measurementsat SPring-8. Competing interests: The authors have nocompeting interests. Data and materials availability: Alldata are available in the main text or in the supplementary materials.

SUPPLEMENTARY MATERIALS

www.sciencemag.org/content/363/6423/161/suppl/DC1Materials and MethodsSupplementary TextFigs. S1 to S60Table S1References (28–57)Movies S1 to S7

4 March 2017; resubmitted 12 September 2017Accepted 23 November 201810.1126/science.aan1019

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Nematic-to-columnar mesophase transition by in situ supramolecular polymerizationKeiichi Yano, Yoshimitsu Itoh, Fumito Araoka, Go Watanabe, Takaaki Hikima and Takuzo Aida

DOI: 10.1126/science.aan1019 (6423), 161-165.363Science 

, this issue p. 161Scienceoptical stimuli could lead to a second ordering transition.stabilized by polymerizing the disks. The orientation of the twisted columns could be altered using electric fields, whereasenough affinity between the disks and rods so that they formed a blended twisted columnar phase. The phase could be

found the right recipe that allowedet al.When the two types of molecules are mixed, they tend to phase separate. Yano Disk-shaped molecules tend to stack in columns, whereas rod-shaped ones tend to align parallel to each other.

Mating disks and rods into an ordered phase

ARTICLE TOOLS http://science.sciencemag.org/content/363/6423/161

MATERIALSSUPPLEMENTARY http://science.sciencemag.org/content/suppl/2019/01/09/363.6423.161.DC1

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