Self-Organized Formation of Parallel-Banded Structures through

Subscriber access provided by Binghamton University | Libraries

Article

Self-organized Formation of Parallel-banded Structures though Synchronization of Twisted Growth Shingo Mizue, Shunsuke Ibaraki, Ryuta Ise, Gen Sazaki, Yuya Oaki, and Hiroaki Imai Cryst. Growth Des., Just Accepted Manuscript • Publication Date (Web): 30 May 2017 Downloaded from http://pubs.acs.org on May 30, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Crystal Growth & Design is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

Cover page Self-organized Formation of Parallel-banded Structures through Synchronization of Twisted Growth Shingo Mizue,1 Shunsuke Ibaraki,1 Ryuta Ise,1 Gen Sazaki,2 Yuya Oaki,1 and Hiroaki Imai1* 1

Department of Applied Chemistry, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan 2

Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo 060-0819, Japan

Self-organized formation of parallelbanded structures was demonstrated through the twisted growth of K2Cr2O7 in a thin layer of a viscous solution containing poly(acrylic acid) on a glass substrate. Dense branching of the twisted crystals was induced by increasing their growth rate under a controlled flow of nitrogen gas. Periodically banded structures were then produced by the synchronization of the twist in the parallel branches. Specific structural colors originating from the parallel-banded structures as a diffraction grating were observed on the self-organized patterns of the twisted crystals.

*To whom correspondence should be addressed. Hiroaki Imai Department of Applied Chemistry, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan Phone +81 45 566 1556. Fax: +81 45 566 1551. Email: [email protected]

ACS Paragon Plus Environment

1


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 22

Self-organized Formation of Parallel-banded Structures though Synchronization of Twisted Growth Shingo Mizue,1 Shunsuke Ibaraki,1 Ryuta Ise,1 Gen Sazaki,2 Yuya Oaki,1 and Hiroaki Imai1* 1

Department of Applied Chemistry, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan

2

Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo 060-0819, Japan

KEYWORDS Crystal growth; Self-organization; Pattern formation; Dendrite.

ABSTRACT. Self-organized formation of parallel-banded structures was demonstrated through the twisted growth of K2Cr2O7 in a thin layer of a viscous solution containing poly(acrylic acid) on a glass substrate. Dense branching of the twisted crystals was induced by increasing their growth rate under a controlled flow of nitrogen gas. Periodically banded structures were then obtained by the synchronization of the twist in the parallel branches. Specific structural colors


2

Page 3 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


originating from the parallel-banded structures as a diffraction grating were observed on the selforganized patterns of the twisted crystals.

Introduction The formation of helical morphologies of achiral crystals is known as a particularly interesting phenomenon.1–17 Eshelby twists on metal whiskers originate from screw dislocation.18 Lamellar twists of polymer crystals are derived from the surface stress caused by the tilt of the molecular chain.19–28 The asymmetric attachment of small units is another route to helical structures.14 In previous works, the formation of twisted crystals has mainly been regarded as the result of intrinsic reasons, such as dislocation stress or the distortion of crystal structures. On the other hand, our research group reported that external factors, such as the concentration field around the growing tip, are essential for the twisted growth of crystals with a low crystallographic symmetry in gel-like viscous matrices.29 Twisted morphologies consisting of K2Cr2O7 crystals are commonly produced in gel matrix (Figure S1).3 −6, 8−10 The specific shapes were found to be formed by twisted stacking of unit plates in a specific direction.9, 10 According to our previous work, the presence of a coincidence-site lattice like a twin boundary was suggested between the stacked units. Thus, specific forces are not needed to hold the structures. Recently, the twisted growth was associated with the periodic change in the concentration field around the growing tip (Figure S2).29 In this case, the mode of growth can be controlled by changing the external fields. The present article shows that twisted growth is successfully synchronized by varying the growth velocity in a gas flow and is applicable for self-organized formation of diffraction gratings consisting of parallel-banded structures.


3


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 22

Spherulites are generally formed by the crystallization of a polymer from its melt and solution. In polymer spherulites, lamellar twists of molecular crystals, such as polyethylene,20 aspirin,30 poly(trimethylene terephthalate),31 and poly(ethylene adipate)32, 33 produce two-dimensional (2D) concentric ring patterns on a substrate as shown in Figure 1a, c. The periodic bands in the rings have been characterized by their associations with the conditions and mechanisms of the radial grwoth.20–25, 34–46 However, the control of the growth direction and the periodicity of the banded structures has not been achieved by conventional techniques. If parallel structures consisting of periodic bands are fabricated on a substrate through twisted crystal growth to a constant direction (Figure 1b, d), we would obtain a new micropatterning technique through self-organization for specific structures, such as diffraction gratings.

Figure 1. Schematic illustration and SEM images of a banded spherulites (a, c) and a parallel banded structure (b, d) consisting of twisted K2Cr2O7 ribbons. The spherulites of twisted K2Cr2O7 ribbons was obtained on a glass substrate by dropping of a small amount of solution containing poly(acrylic acid) (PAA) and subsequent natural drying.10 The parallel-banded structures were obtained in the present study.


4

Page 5 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


In the present study, the self-organized formation of 2D structures was demonstrated through the crystal growth of K2Cr2O7 in a thin layer of a viscous solution containing poly(acrylic acid) (PAA) on a glass substrate. Parallel-banded structures were obtained by twisted growth of the branches under a controlled flow of nitrogen gas (Figure 1b, d). We controlled the growth direction with synchronization of the pitch and phase of twists. The formation mechanism of the parallel-banded structures is discussed on the basis of the diffusion field around the growing tip observed in situ. Here, the synchronization of multiple twisted growth is achieved by merging diffusion fields around the growth fronts. We found that the periodic patterns of the parallelbanded structures perform as a diffraction grating exhibiting specific structural colors.

Experimental Section Preparation of samples Precursor solutions were prepared by dissolving K2Cr2O7 (Junsei Chemical) (space group P-1) and PAA (MW: 250,000, 35wt% aqueous solution, Sigma-Aldrich) in 100 g of purified water at room temperature. The concentrations of K2Cr2O7 and PAA ([K2Cr2O7] and [PAA]) were varied in a range of 5 to 15 g/100 g of water. Glass slides washed with acetone and purified water were dip-coated with the precursor solution at a withdrawal rate of 1.6 mm/s at room temperature (Figure S3). Dipped glass slides were kept under saturated water vapor for 3 min to prevent rapid evaporation and then placed in a nitrogen gas flow at a linear velocity of 0.05−2.22 m/s. As water evaporated from the precursor solution, crystal growth proceeded along the glass substrate.

Characterization


5


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 22

The crystal morphology was observed with a scanning electron microscope (SEM, Keyence VE-9800) and an optical microscope (Keyence VK-9710). Structural analysis of the products on the glass slides was performed using an X-ray diffractometer (XRD, Rigaku MiniFlex II) with Cu Kα radiation using the θ−2θ scanning method. The periodicity of 2D structures on a substrate was characterized as light grating by the diffraction of a beam (λ = 650 nm, φ = 3 mm) from a semiconductor laser. The structural color originating from a 2D structure was observed under the illumination of a white light with an optical microscope (Keyence VH-S30F) and a spectrometer (Hamamatsu C10027-01) while changing the incident angle. The growth behavior of K2Cr2O7 crystals was directly observed on a glass substrate using the optical microscope and a Michelson interferometer (Nikon M Plan 2.5 TI). The macroscopic concentration field around the twisting crystal was observed using reflection from the backside of the glass substrate.

Results and Discussion Parallel-banded structures of K2Cr2O7 We utilized the crystal growth of a triclinic K2Cr2O7 in a PAA matrix because twisted crystals are easily produced in this system.3–6, 8–10 Millimeter-size helical architectures were obtained in a bulky gelatin matrix supersaturated with K2Cr2O7, as reported in our previous article.9 A large backbone of helical K2Cr2O7 was formed in a gelatin matrix (Figure. S1). The backbone of K2Cr2O7 grown in gelatin is elongated in the b direction and consists of tilted planer units that are twisted with a rotation of approximately 12° on the (010) plane. Detailed explanations of the twisted structures and their formation mechanism were reported in our previous articles.9, 29 In the present work, 2D dendrites consisting of helical K2Cr2O7 were produced on a glass substrate (Figure 2a, c) by the dip-coating and subsequent drying of aqueous solutions containing K2Cr2O7


6

Page 7 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(5–15 g/100 g of water) and PAA (5–15 g/100 g of water). The branches were found to be twisted (Figure 2c−e). On the basis of the detailed observation of the K2Cr2O7 crystals grown in gelatin and PAA matrices (Figure S1),9, 10 micrometric twisted morphologies were deduced to be formed by staking of platy units on the substrate. The presence of 020, 200, 210, and 2-11 reflections and the absence of hkl (l ≠ 0) signals including -111 and 0-12 of K2Cr2O7 in the typical XRD pattern (Figure 2b) indicate that the c ([001]) direction of the twisted crystals was parallel to the substrate. This means that the K2Cr2O7 dendrites are elongated in the c direction in a PAA matrix. As reported in our previous articles,9,

29

the stacking of the unit plates was

suggested to be perpendicular to the b-plane in the gelatin matrix. In this case, however, the twists are inferred to be normal for the c-plane in the PAA matrix (Figure S1). Differences in the polymer matrix may change the stacking direction of planer units in the twisted structure. Here, the growth direction of branched in the K2Cr2O7 dendrites was not controlled by natural drying. Basically, the same amounts of the right- and left-handed ribbons are formed in a matrix of achiral molecules.10 On the other hand, the right-handed ribbons are mainly produced in natural polymers, such as gelatin, agar, and pectin. Detailed mechanism on the control of handedness was discussed in our previous article.10 We observed almost the same amounts of the right- and left-handed ribbons in the PAA matrix due to the absence of molecular chirality. Here, the handedness of the helical ribbons was not discussed because it is not essential for the formation of parallel-banded structures. In order to control the crystal growth, we varied the drying rate of the solutions coated on the substrate under a flow of nitrogen gas. We obtained 2D parallel-banded structures on the substrate (Figure 3), when [K2Cr2O7] and [PAA] were 5 : 5, 10 : 10, and 15 : 15 (g/100 g of water) (Figure 4a). Suitable flow velocity values for the parallel-banded structures were 0.2–0.4,


7


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 22

0.6–0.8, and 0.8–1.1 m/s for the concentration ratios 5 : 5, 10 : 10, and 15 : 15 (g/100 g of water), respectively (Figures 4b and S4). When the value was lower than the suitable flow velocity, the random branching of K2Cr2O7 crystals was observed with a relatively low growth rate, and their growth direction was not controlled. A large number of nuclei were randomly formed when flow velocities were higher than suitable. The concentration ratio of K2Cr2O7 and PAA was an essential factor in the morphological variation of the grown crystals. By adjusting the ratio (1 : 1 in weight), 2D parallel-banded structures consisting of twisted branches were obtained on the substrate. The addition of an excess amount of K2Cr2O7 induced the random branching of K2Cr2O7 crystals with any growth rates. Crystal growth was suppressed by the presence of a large amount of PAA. Bands were composed of twisted branches with a helical pitch of ~7–8 µm for 180°-rotation (Figures 3 and S4). Symmetric arcs were observed on a screen by the diffraction of a laser beam through the parallel-banded structure (Figure 3i). This means that the K2Cr2O7 crystals grown on the substrate perform as a diffraction grating with periodicity of ~7 µm. On the other hand, the diffraction spots of a laser beam were not observed from the random 2D structure (Figure 2d) because the branching occurred randomly and the directions of branches were not oriented. In parallel-banded structures, K2Cr2O7 twisted crystals grew in the same direction and with the same pitch and phase (Figure 3k, l). This suggests that twists of multiple growth fronts are synchronized under a specific condition. As shown in the schematic illustration (Figure 3m), the parallel-banded structure is comprised of twisted crystals that consist of small units similar to the helical morphology obtained in a bulky gelatin. We observed structural colors from the diffraction grating formed in a millimeter-scale area by backlighting of white light (Figure 3a).


8

Page 9 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


The growth rate influenced the helical period and branching rate of ribbons. As shown in Figure S4, the half pitch of the twisted crystals was changed with changing the growth conditions. The helical period decreased with increasing growth rate. For example, twists with a helical pitch of ~50 µm for 180°-rotation were obtained with a growth rate of 43 µm/s in random branches (Figure 2). On the other hand, the helical ribbons with a helical pitch of ~7–8 µm were formed by a rapid growth of 560 µm/s (Figure 3). As shown in Figure 2c, d, the branching was basically synchronized with the twist of the ribbons. Thus, the branching or twisting rate steeply increased with increasing growth rate and was roughly estimated to be ~1 and ~70/s for the growth rates of 43 and 560 µm/s, respectively. However, basically, the parallel-banded structures were comprised of the twisted structures only with a half pitch of ~7–8 µm because the condition for the synchronization of the twisted fronts is highly limited with a certain growth rate. Thus, we need further investigation for controlling the periodicity of the banded structures formed by the self-organized crystal growth.


9


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 22

Figure 2. Typical optical micrograph (a), XRD pattern (b), SEM images (c, d), and schematic illustration (e) of K2Cr2O7 twisted crystals grown on a substrate with PAA ([K2Cr2O7] = [PAA] = 10 g/100 g of water). (b) Blue, green, and red indicate 001, 020, and 2-11 planes that are facets of the planer unit, respectively. Purple indicates hk0 signals assigned to plains parallel to the caxis. Many other peeks that are assigned to hkl (l ≠ 0) plains non-parallel to the c-axis are not observed in the XRD pattern. (f) Diffraction image of a laser beam from the 2D structures without the gas flow. The distance between the 2D structures and the screen was 100 mm. (g) The growth rate of K2Cr2O7 twisted crystals grown on a substrate with PAA.


10

Page 11 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 3. Optical micrographs (a, b), SEM images (c, e), schematic illustrations (d), and growth rates (g) of K2Cr2O7 crystals with the gas flow ([K2Cr2O7] = [PAA] = 10 g/100 g of water). (f) Diffraction image of a laser beam from the 2D structures with the gas flow. The distance between the 2D structures and the screen was 100 mm.


11


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 22

Figure 4. Morphological variation of the grown crystals with changing parameters, such as [K2Cr2O7], [PAA], and flow velocity. (a) Influence of [K2Cr2O7] and [PAA] in a suitable flow velocity shown in (b). (b) Influence of [K2Cr2O7], [PAA], and flow velocity. [PAA] was equal to [K2Cr2O7] in (b).

Figure 5. SEM images of the transient region from the random branching region to the parallelbanded structures of K2Cr2O7 crystals. (I) Random branching, (II) transient, and (III) parallelbanded structures.


12

Page 13 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 5 shows the transition of the twist morphology from random branching to parallelbanded structures in which the pitch and the phase of twisting were synchronized. Dendritic morphologies consisting of twisted crystals were grown without the gas flow in Region I. Parallel-banded structures comprised of synchronized twisted crystals with pitches of 7−8 µm were observed under a suitable gas flow in Region III. The widths of the crystals were ~6 µm and ~1 µm in the sparse dendrites and densely packed bands, respectively. Region II is a transient area between random branching and banded structures. These results indicate that the growth mode of randomly grown branches was gradually synchronized with further branching by adjusting the drying rate. Finally, parallel-banded structures were formed in the progressive stages. In our previous article,29 twisted growth was reported to be associated with the oscillation of the concentration field around the growing tip (Figure S2). Here, we monitored the concentration field during formation of parallel-banded structures of K2Cr2O7 with PAA using a Michelson two-beam interferometer. Figure 6 shows optical micrographs, interference figures, and schematic images of the growth front of K2Cr2O7 crystals in the viscous matrix with and without the gas flow. Relatively large twisted dendrites were observed with a relatively slow growth rate (Figure 2) without the gas flow as shown in Figure 6a, d, f. The direction and periodicity of the growing crystals were not regulated in isolated diffusion fields. The branching of the dendrites was promoted in the gas flow and fine branches were then formed at the growth front (Figure 6b). The growth direction of the branches was aligned with the dense branching (Figure 6c) as the growth rate increased with the gas flow and parallel-banded structures were then formed (Figure 3). The diffusion fields around the growing tips were shrunken and merged with densification of the growing branches at the front (Figure 6e). The merge of the diffusion fields around the


13


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 22

growing tips would lead synchronization of the oscillation of the concentration at the growing tips (Figure 6g). Since the pitch and phase of the twisted growth are associated with the oscillation of the concentration, parallel-banded structures are achieved by the synchronization at the front of the branches.

Figure 6. Optical micrographs (a−c), interference figures (d, e), and schematic images (f, g) of the growth front of K2Cr2O7 crystals in the gel matrix without the gas flow (a, d, f) and with the suitable gas flow (c, e, g). Interference fringes parallel to the growing direction. Red lines in the schematic illustrations indicate the presence of the diffusion field around the growing tip. The interference fringes were perpendicular to the growing direction of the crystals. The semicircular deformation of fringes that indicated the concentration field was observed around the tip of the crystals. In panel (d) for random growth of the dendrites, a concentration field with a radius of


14

Page 15 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


ca. 100 µm was observed around the growing tip. The helical pitch of the twists in the dendrites was about 40 µm (Figure 2). In panel (e) for the parallel banded structures, the concentration fields were not recognized because their size was too small for the interference fringes in this system. The helical pitch of the parallel banded structures was about 8 µm.

Angle-dependent structural color of banded structures As shown in Figure 7, we observed specific structural colors on the banded patterns having the pitch of ~7−8 µm backlighted with a white light source. The color change from blue to orange was observed by a microscope and a spectrometer in light transmitted through the parallelbanded structures at incident angles of ~3−5°. Figure 7b indicates spectra of angle-dependent structural color of blue, green and yellow shown in Figure 7a. Calculated incident angles of blue (470 nm), green (510 nm) and yellow (560 nm) using the periodicity of 7.5 µm are 3.6°, 3.9° and 4.3°, respectively. The spectral change with those incident angles agreed with the color observed by the diffraction grating with the periodicity of ~7−8 µm. Thus, the periodic patterns composed of twisted crystals provide specific structural colors originating from their periodicity. As shown in Figure 3a, the structural color was homogeneously observed in a large area over 5 mm. We observe the similar colors on the concentric patterns consisting of twisted ribbons in a spherulites. However, the homogeneity of the color of the parallel banded structures is much better than that of the spherulites. The banded structures are formed from a nucleus at the center of the spherulites (Figure 1a). Thus, the synchronization of the twist occurs spontaneously only in the limited area because the pitch and phase are originally the same. On the other hand, the twists of the branches are gradually synchronized by merging of the concentration fields with


15


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 22

increasing growth rate under the gas flow (Figure 6). Finally, parallel-banded structures consisting of synchronized twists are produced in millimeter-sized area on a substrate. Very recently, we observed parallel banded structures by helical growth of K2SO4 and poly(ethylene adipate). The specific architectures obtained in gel-like matrices are now being investigated to expand the particular phenomenon to other materials.

Figure 7. Micrographs and spectra of angle-dependent structural colors of light transmitted through parallel-banded structures.


16

Page 17 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Conclusion We produced diffraction gratings consisting of parallel-banded structures on a glass substrate by the dip-coating of solutions of K2Cr2O7 with poly(acrylic acid). The parallel banded structures were obtained by the synchronization of twisted crystal growth when the growth rate was increased in a controlled flow of nitrogen gas. The periodic patterns composed of twisted crystals exhibited specific structural colors originating from their periodicity. The controlled crystallization with the twisted growth mode would be applicable to a new type of patterning technique through self-organization.

AUTHOR INFORMATION Corresponding Author Hiroaki Imai Department of Applied Chemistry, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan Phone +81 45 566 1556. Fax: +81 45 566 1551. Email: [email protected]

ACKNOWLEDGMENT


17


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 22

This work was partially supported by Grant-in-Aid for Scientific Research (A) (16H02398) from Japan Society for the Promotion of Science. .

REFERENCES (1) Garcia-Ruiz, J. M. J. Cryst. Growth 1985, 73, 251–262. (2) Garcia-Ruiz, J. M.; Carnerup, S. T. A. M.; Christy, A. G.; Van Kranendonk, M. J.; Welham, N. J. Science 2003, 302, 1194–1197. (3) Suda, J.; Matsushita, M. J. Phys. Soc. Jpn. 1995, 64, 348–351. (4) Suda, J.; Nakayama, T.; Nakahara, A.; Matsushita, M. J. Phys. Soc. Jpn. 1996, 65, 771– 777. (5) Suda, J.; Nakayama, T.; Matsushita, M. J. Phys. Soc. Jpn. 1998, 67, 2981–2983. (6) Suda, J.; Matsushita, M.; Izumi, K. J. Phys. Soc. Jpn. 2000, 69, 124–129. (7) Gower, L. A.; Tirrell, D. A. J. Cryst. Growth 1998, 191, 153–160. (8) Oaki, Y.; Imai, H. Cryst. Growth Des. 2003, 3, 711–716. (9) Imai, H.; Oaki, Y. Angew. Chem. Int. Ed. 2004, 43, 1363–1368. (10) Oaki, Y.; Imai, H. J. Am. Chem. Soc. 2004, 126, 9271–9275. (11) Oaki, Y.; Imai, H. Langmuir 2005, 21, 863–869. (12) Imai, H.; Oaki, Y. CrystEngComm, 2010, 12, 1679–1687.


18

Page 19 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(13) Wang, M.; Li, D. W.; Shu, D. J.; Bennema, P.; Mao, Y. W.; Pan, W.; Ming, N. B. Phys. Rev. Lett. 2005, 94, 125505. (14) Shtukenberg, A. G.; Punin, Y. O.; Gujral, A.; Kahr, B. Angew. Chem., Int. Ed., 2014, 53, 672–699. (15) Yu, S. H.; Colfen, H.; Tauer, K.; Antonietti, M. Nat. Mater. 2005, 4, 51–55. (16) Terada, T.; Yamabi, S.; Imai, H. J. Cryst. Growth 2003, 253, 435–444. (17) Giraldo, O.; Brock, S. L.; Marquez, M.; Suib, S. L.; Hillhouse, H.; Tsapatsis, M. Nature, 2000, 405, 38. (18) Eshelby, J. D. J. Appl. Phys. 1953, 24, 176–179. (19) Toda, A.; Okamura, M.; Taguchi, K.; Hikosaka, M.; Kajioka, H. Macromolecules. 2008, 41, 2484–2493. (20) Keith, H. D.; Padden Jr, F. J. Macromolecules 1996, 29, 7776–7786. (21) Owen, A. J. Polymer 1997, 38, 3705–3708. (22) Ye, H.-M.; Xu, J.; Guo, B.-H.; Iwata, T. Macromolecules 2009, 42, 694–701. (23) Iwata, T.; Doi, Y. Macromolecules 2000, 33, 5559–5565. (24) Maillard, D.; Prud’homme, R. E. Macromolecules 2008, 41, 1705–1712. (25) Kikkawa, Y.; Abe, H.; Iwata, T.; Inoue, Y.; Doi, Y. Biomacromolecules 2002, 3, 350– 356. (26) Keith, H. D.; Padden Jr, F. J. Polymer, 1984, 25, 28–42.


19


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 22

(27) Toda, A.; Okamura, M.; Taguchi, K.; Hikosaka, M.; Kajioka, H. Macromolecules 2008, 41, 2484–2493. (28) Li, Y.; Yan, D.; Cheng, S. Z. D.; Bai, F.; He, T.; Chien, L. C.; Harris, F. W.; Lotz, B. Macromolecules 1999, 32, 524–527. (29) Ibaraki, S.; Ise, R.; Ishimori, K.; Oaki, Y.; Sazaki, G.; Yokoyama, E.; Tsukamoto, K.; Imai, H. ChemComm 2015, 51, 8516–8519. (30) Cui, X.; Rohl, A.; Shtukenberg, A. G.; Kahr, B. J. Am. Chem. Soc. 2013, 135, 3395–3398. (31) Yun, J. H.; Kuboyama, K.; Chiba, T.; Ougizawa, T. Polymer 2006, 47, 4831–4838. (32) Li, Y.; Huang, H.; He, T.; Wang, Z. ACS Macro Lett. 2012, 1, 154–158. (33) Point, J. J. Polymer, 2006, 47, 3186–3196. (34) Lugito, G.; Wang, L. Y.; Woo, E. M. Macromol. Chem. Phys. 2014, 215, 1297–1305. (35) Gibbs, H. D. J. Am. Chem. Soc. 1906, 28, 1395–1422. (36) Nurkhamidah, S.; Woo, E. M. Colloid Polym. 2012, 290, 275–288. (37) Lee, L. T.; Woo, E. M.; Hsieh, Y. T. Polymer 2012, 53, 5313–5319. (38) Hsieh, Y. T.; Woo, E. M. Polym. Lett. 2013, 7, 396–405. (39) Schultz, J. M. Macromolecules 2013, 46, 4227–4229. (40) Xu, J.; Guo, B. H.; Zhang, Z. M.; Zhou, J. J.; Jiang, Y.; Yan, S.; Li, L.; Wu, Q.; Chen, G. Q.; Schultz, J. M. Macromolecules 2004, 37, 4118–4123.


20

Page 21 of 22

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(41) Su, C. C.; Woo, E. M.; Hsieh, Y. T. Phys. Chem. Chem. Phys. 2013, 15, 2495–2506. (42) Nurkhamidah, S.; Woo, E. M. Macromol. Chem. Phys. 2013, 214, 673–680. (43) Wu, P. L.; Woo, E. M.; Liu, H. L. Polym. Phys 2004, 42, 4421–4432. (44) Woo, E. M.; Nurkhamidah, S. J. Phys. Chem. B 2012, 116, 5071–5079. (45) Woo, E. M.; Nurkhamidah, S.; Chen, Y. F. Phys. Chem. Chem. Phys. 2011, 13, 17841– 17851. (46) Woo, E. M.; Wang, L. Y.; Nurkhamidah, S. Macromolecules 2012, 45, 1375–1383.


21


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 22

For Table of Contents Use Only Self-organized Formation of Parallel-banded Structures through Synchronization of Twisted Growth Shingo Mizue,1 Shunsuke Ibaraki,1 Ryuta Ise,1 Gen Sazaki,2 Yuya Oaki,1 and Hiroaki Imai1* 1Department of Applied Chemistry, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan 2Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo 060-0819, Japan

Parallel-banded structures were formed through the synchronization twisted growth of the branches. Specific structural colors originating from the periodic patterns were observed on the banded morphologies of twisted crystals.


22

Self-Organized Formation of Parallel-Banded Structures through

Recommend Documents