Seeded Mineralization Leads to Hierarchical CaCO3 Thin Coatings on

Subscriber access provided by UNIV OF DURHAM

Article

Seeded Mineralization Leads to Hierarchical CaCO3 Thin Coatings on Fibers for Oil/Water Separation Applications Ming Li, Yupeng Chen, Li-Bo Mao, Yuan Jiang, Mingfeng Liu, Qiaoling Huang, Zhiyang Yu, Shutao Wang, Shu-Hong Yu, Changjian Lin, Xiang Yang Liu, and Helmut Cölfen Langmuir, Just Accepted Manuscript • DOI: 10.1021/acs.langmuir.7b03813 • Publication Date (Web): 13 Feb 2018 Downloaded from http://pubs.acs.org on February 13, 2018

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 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 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.

Langmuir 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 41 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

Langmuir

Seeded Mineralization Leads to Hierarchical CaCO3 Thin Coatings on Fibers for Oil/Water Separation Applications Ming Li†,[+], Yupeng Chen§, [+], Li-Bo Mao‡,[+], Yuan Jiang*,†, Ming-Feng Liu†, Qiaoling Huang†, Zhiyang Yu☨, Shutao Wang*,§✚, Shu-Hong Yu*,‡, Changjian Linǁ, Xiang Yang Liu†,¶, and Helmut Cölfen# †

Department of Biomaterials, College of Materials, Research Institute for Soft Matter and

Biomimetics, Fujian Provincial Key Laboratory for Soft Functional Materials Research, Xiamen University, Xiamen 361005, China §

CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for

Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China ‡

Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at the

Microscale, CAS Center for Excellence in Nanoscience, Collaborative Innovation Center of Suzhou Nano Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China

1 ACS Paragon Plus Environment

Langmuir 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

✚

☨

University of Chinese Academy of Sciences, Beijing 100049, P. R. China.

School of Materials Science and Engineering, Xiamen University of Technology, Xiamen

361024, P. R. China ǁ

State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry,

College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China ¶

Department of Physics, Faculty of Science, National University of Singapore, 117542,

Singapore #

Physical Chemistry, University of Konstanz, Konstanz 78457, Germany

Keywords

Bio-inspired mineralization, prismatic-type mineral, superwetting behavior, thin coating, oil-water separation, calcium carbonate, hierarchical architecture, morphosynthesis

ABSTRACT:

Like their biogenic counterparts, synthetic minerals with hierarchical architectures should exhibit (multiple) structural functions, which nicely bridge the boundaries between engineering and functional materials. Nevertheless, design of bio-inspired mineralization approaches to thin 2 ACS Paragon Plus Environment

Page 2 of 41

Page 3 of 41 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

Langmuir

coatings with distinct micro-/nano-textures remains challenging in the realm of materials chemistry. Herein, a general morphosynthetic method based on seeded mineralization was extended to achieve prismatic-type thin CaCO3 coatings on fibrous substrates for oil/water separation applications. Distinct micro-/nano-textures of the overlayers could be obtained in mineralization processes in the presence of different soluble (bio)macromolecules. These hierarchical thin coatings therefore exhibit multiple structural functions including underwater superoleophobicity, ultra-low adhesion force of oil in water, and comparable stiffness/strength to the prismatic-type biominerals found in mollusk shells. Moreover, this controllable approach could proceed on fibrous substrates to obtain robust thin coatings, so that a modified nylon mesh could be employed for oil/water separation driven by gravity. Our bio-inspired approach based on seeded mineralization opens the door for deposition of hierarchical mineralized thin coatings exhibiting multiple structural functions on planar and fibrous substrates. This bottom-up strategy could be readily extendable for syntheses of advanced thin coatings with a broad spectrum of engineering and functional constituents.

INTRODUCTION

Biominerals with characteristic complex and even hierarchical architectures show (multiple) structural functions.1, 2 The appearance of these structural functions can be largely attributed to 3 ACS Paragon Plus Environment

Langmuir 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 41

the presence of specific mesoscopic architectures and their structural uniformity across the macroscopic distance. More importantly, this biogenic structural design nicely reconciles seemingly contradictory properties like hardness and strength with toughness and ductility.3, 4 For instance, the nacreous-type biominerals found in mollusk shells can conciliate stiffness and toughness by taking advantage of the lamellar architecture composed of submicron sized platelets of aragonitic CaCO3.5, 6 Design of bio-inspired approaches to hierarchical thin coatings can hence transform eco-friendly engineering constituents into robust architectures with emerging (multiple) structural functions.6-14 Application of bio-inspired mineralization routes to thin coatings of CaCO3 – the most abundant biomineral – is one example. Though numerous mesostructural architectures in bio-inspired products could be obtained15, they nevertheless lack macroscopic structural continuity owing to the limited heterogeneous nucleation spots and the poor adhesion of reactants in a dynamic mineralization process. It is noteworthy to state that a bio-inspired mineralization process in the presence of a relatively high amount of a soluble polymer additive could provide a reliable pathway in achieving continuous thin coatings.8, 9, 11, 16-21

Occlusion of high concentrations of polymeric constituents in the products nonetheless can

cause granular thin coatings with moderate crystallinity, accompanying the demolition of mesostructural architectures and decreased strength.8, 11, 19, 22, 23 Also, working with small amounts of polymeric additives using polymer liquid precursors of CaCO3 yielded thin films composed of a patchwork of crystalline units.24 It remains technically challenging to explore


Page 5 of 41 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

Langmuir

controllable mineralization pathways to continuous hierarchical CaCO3 thin coatings with structural reinforcement and (multiple) emerging functions.

A growing number of bio-inspired studies based on different mineralization strategies have been successful in delivering continuous CaCO3 films with distinct mesostructural architectures and remarkable functional outcomes.14, 21, 25, 26 For instance, our previous study showed that seeded mineralization could become a general approach to producing prismatic-type mineralized thin coatings.14 The vaterite thin films with oriented reinforcement show comparable mechanical properties to their biogenic counterparts found in mollusk shells. It is next an important task to fabricate these hierarchical thin coatings on fibrous substrates, where the products could find more applications to satisfy increasing functional requests. To date, various synthetic and biomacromolecular fibers including Kevlar,27-29 nylon,30 polypropylene,31 collagen,17 silk fibroin,32 cellulose acetate,33 and metal–organic protein frameworks34 have been employed as substrates for CaCO3 mineralization. Nevertheless, no study has been successful in achieving a hierarchical CaCO3 thin coating with structural continuity & uniformity across a macroscopic distance on a fibrous substrate, hindering widespread applications which take advantage of structural functions and the inherent properties of CaCO3 such as light reflectance and gas/water permeability.

The current study extends the success of seeded mineralization for the fabrication of calcite (the thermodynamically stable polymorphic form of CaCO3 at room temperature) thin coatings 5 ACS Paragon Plus Environment

Langmuir 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 41

on both planar and fibrous substrates. The thin coatings show emerging underwater superoleophobicity and ultralow adhesion force of oil in water owing to the exterior hierarchical micro-/nano-texture. In addition, they exhibit comparable mechanical properties to prismatic-type biominerals found in mollusk shells. Intriguingly, the specific hierarchical architecture could be readily transferred onto a fibrous substrate to obtain robust thin coatings, where the stress caused by the curvature was released because of the granular nature of the overlayer. A nylon mesh with the above coating therefore showed excellent performance in oil/water separation just driven by gravity. Unlike its soft counterparts, where superoleophobicity will be deteriorated gradually in the presence of fluid flush and inevitable scraping/rubbing,35-41 the robust coating introduced herein is advantageous for withstanding mechanical damages. Hence, a synthetic approach based on seeded mineralization successfully transforms a sustainable engineering material – CaCO3 to hierarchical thin coatings with multiple structural functions on fibrous substrates, offering significant opportunities for the coating industry.

EXPERIMENTAL SECTION Preparation of the Polymer Coating. Chitosan (Mw = 3.0×105 g mol-1, viscosity: 800-2000 cP, deacetylation degree: 95%, Sigma-Aldrich) was used as the substrate for CaCO3 mineralization. Chitosan thin films were prepared via a spin-coating or dip-coating approach and used without any further treatment. For the planar substrate, a volume of 30 µL 1 wt% chitosan-acetic acid solution was dropped onto a clean cover glass (1.2 cm × 1.2 cm, pretreated 6 ACS Paragon Plus Environment

Page 7 of 41 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

Langmuir

with Piranha solution), followed by a spin-coating process using a spin rate at 5000 rpm for 1 min. For the curved surface, the nylon fiber or mesh (300 mesh size, pretreated with sodium hydroxide solution) was dip-coated with a layer of 2 wt% chitosan-acetic acid solution using a rate of 0.5 rpm.

Deposition of the Seed Layer. In a typical procedure to achieve the seed layer, the mineralization was conducted by the slow diffusion of CO2 (based on the decomposition of NH4HCO3 (AR, Sinopharm Chemical Reagent)) into a volume of 4 mL 20 mM CaCl2 (aq) (AR, Sinopharm Chemical Reagent) in presence of 0.01 g L-1 poly(acrylic acid sodium salt) (PAA; Mw = 2.1 × 103 g mol-1, 50 wt% in water, Sigma-Aldrich) as the additive in a closed desiccator for about 36 h. Subsequently, the hybrid thin film was removed and rinsed twice with degassed purified water (obtained from Millipore, Direct-Q3 and boiled for 0.5 h to remove CO2 before use) before being used for characterization or overgrowth.

Overgrowth of the prismatic-type layer. For the overgrowth of the calcitic prismatic layer, the solution was prepared using CaCl2 solutions with poly-L-γ-glutamic acid sodium salt (PGlu; Sigma-Aldrich), silk-fibroin (SF; purified from the larvae of Bombyx mori), or poly(sodium 4-styrenesulfonate) (PSS; average Mw ~70,000, Sigma-Aldrich) as the additives. The overgrowth occurred on the granular CaCO3-PAA seed layer in the presence of 1 g L-1 PGlu, SF, or PSS in a closed desiccator with slow diffusion of CO2 for about 48 h. The concentration of Ca2+ was constant at 20 mM for all overgrowth experiments. 7 ACS Paragon Plus Environment

Langmuir 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 41

Other Related Experiments. To investigate the importance of the seed layer, the deposition of the CaCO3-PGlu hybrid was performed on the chitosan membrane. The epitaxial growth of the calcitic prismatic layer with different concentrations of PGlu was conducted to study the effect of the concentration of the polymer additives on the morphology and structure of the mineralization layer, where the concentrations of PGlu were 0.1 g L-1, 1 g L-1 and 5 g L-1, respectively. A comparison overgrowth was performed in the absence of polymer additives. To obtain the curve-shaped continuous calcite single crystals, the mineralization was deposited on the CaCO3-PGlu hybrid layer with the concentration of PGlu ranging from 1 g L-1 to 0.02 g L-1.

Oil/Water Separation Experiment. A nylon mesh coated with CaCO3 thin film was fixed between two PMMA tubes. Subsequently, the mixtures of oil and water (30% v/v) were poured into the upper tube. The separation was achieved by the gravity of the liquids merely. Cyclohexane with red dye was used as the detection oil.

Characterization. SEM images of the CaCO3 thin films were collected using a Hitachi SU-70 scanning electron microscope. Samples were prepared by sticking fractured thin films onto a double-sided conducting tape. Samples were coated with a layer of 13 nm platinum by using a JFC-600 sputter coater. An Olympus BX53 optical microscope equipped with polarizers was used for OM & POM observation. X-ray diffraction patterns were collected by using an X’pert PRO, PANalytical, X-ray diffractometer equipped with Cu-Kα radiation. Diffraction patterns were generated with instrument operation at 40 mA and 40 kV and using a step size at 0.016°. A 8 ACS Paragon Plus Environment

Page 9 of 41 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

Langmuir

FEI Talos F200S transmission electron microscope (200kV) was employed to examine the morphology, structure, and chemical components of the CaCO3 thin film. A Focused Ion Beam (FIB)-TEM sample was prepared by using a Zeiss Neon 40EsB. To protect the surface during milling and lift-out, a bar of SiO2 was deposited on the sample using gas-assisted deposition. After lift-out and transferring onto the TEM grid, the sample was polished to the final thickness (~50-80nm) using a 50 pA current. Fourier transform infrared (FT-IR) spectra in the region of 4,000-500 cm-1 were recorded at room temperature by using a Nicolet iS10 spectrometer in ATR mode. Atomic force microscopy (AFM) images were obtained by an atomic force microscope at room temperature to determine the surface features and the roughness of the polymer and seed layer. Nanoindentation data were measured using an Agilent G200 Nano Indenter. The samples on the glass slides were mounted on the holder for testing. The obtained data were analyzed based on Oliver-Pharr method.

For underwater contact angle measurement, both an OCA 25 and an OCA20 instrument (Data-Physics, Germany) were used at ambient temperature. The membrane was first immersed in water. A 3 µL 1,2-dichloroethane droplet was then dropped carefully onto the membrane and the contact angle was measured. The average value of three measurements performed at different positions of the same sample was adopted as the underwater contact angle. The underwater oil-adhesion forces were measured using a high-sensitivity micro-electro-mechanical balance system (Data-Physics DCAT11, Germany). A drop of 1,2-dichloroethane (about 10 µL) was first 9 ACS Paragon Plus Environment

Langmuir 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 41

hung on a small metal ring connected to the microbalance. The membrane immersed in water was controlled to move up to contact with the oil droplet, and then controlled to leave. The force during the process was recorded. The residual oil content in the water collected after the separation was detected using an infrared spectrometer oil content analyzer (CY-2000, China).

RESULTS AND DISCUSSION

A typical seeded mineralization occurring on a planar substrate (i.e. a glass slide) contains three steps. First, a chitosan thin layer obtained via a spin-coating process was employed as the underneath insoluble matrix for the subsequent mineralization use (Figure S1). Next, a slow CO2 diffusion method16 was employed to deposit a seed layer on the chitosan layer, where poly(acrylic acid sodium salt) (PAA) functioned as an additive to achieve the granular texture of spherulitic polydomains (Figure S2a-b). The seed layer was stable under ambient condition and hence, could be characterized by multiple techniques. The XRD pattern confirms that the seed layer is calcite CaCO3 in polymorphic form (Figure S2c). No amorphous halo was detected. The moderate peak intensity is attributed to the thin thickness of the seed layer at a value of about 80 nm. Each spherulitic polydomain is composed of granular CaCO3 and PAA constituents. The presence of a continuous chitosan layer is essential for obtaining a continuous hybrid layer. As a comparison, the same mineralization conditions led to discontinuous polydomains on a glass or plastic (i.e. polyethylene terephthalate) substrate (Figure S3a-b). The chitosan layer meanwhile


Page 11 of 41 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

Langmuir

controls the polymorphic outcome of the seed layer, in accordance to a previous study.18 The granular layer functioned subsequently as the seed for deposition of prismatic-type overlayers.

A typical overgrowth proceeded in the presence of a soluble additive – poly-L-γ-glutamic acid sodium salt (PGlu). A cross-section scanning electron microscopy (SEM) image reveals a prismatic-type overlayer, composed of densely-packed, fan-shaped microdomains (Figure 1a). The fan-shaped spherulitic microdomain herein exhibits a great structural similarity to the initially-grown, prismatic-type biominerals found in sea turtle eggshells.42 The overlayer shows orientational preference, as is confirmed by the dominance of the (104) peak in the XRD pattern (Figure 1c). As a comparison, other peaks are visible in rhombohedral CaCO3 crystals precipitated on a glass substrate (Figure 1c).

A zoomed-in SEM image is particularly instructive as it shows the presence of a clear interface between the seed layer underneath and the overlayer (Figure 1b). Next, TEM was employed for the detailed structural analyses of the overlayer. A typical spherulitic domain diffracts in a similar way as a mesocrystal, which suggests that calcite nanocrystals in a fan-shaped microdomain are highly oriented in the vertical direction (Figure. 1d-e). The diffraction spots are defined and slightly smeared as typical for a mesocrystal15, which indicates that nanocrystalline subunits deviate slightly from the main orientational direction (Figure. 1e). Therefore, multiple tools including SEM & TEM imaging and the XRD pattern evidence that the overlayer in the hybrid thin coating is mesocrystalline in nature. The presence of the 11 ACS Paragon Plus Environment

Langmuir 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 41

densely-packed mesocrystalline microdomains in the overlayer implies that a competition among preferred growth directions exists during the overgrowth procedure. This model of crystal growth has been previously suggested to guide the formation of biogenic minerals found in avian shells,43, 44 mollusk shells,45, 46 and bio-inspired CaCO3 minerals.12

Figure 1. Structural characterization of the prismatic-type CaCO3 thin film. a-b, Cross-section SEM images of a typical CaCO3 thin film, where the interface between the overlayer and the seed layer is denoted with the arrows (b and d). c, XRD patterns of a prismatic-type CaCO3 thin film (top) together with rhombohedral CaCO3 crystals precipitated on a glass substrate (bottom). The abbreviation “c” represents calcite. d-e, TEM image (d) and SAED pattern (e) of a typical 12 ACS Paragon Plus Environment

Page 13 of 41 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

Langmuir

microdomain in the overlayer. TEM samples were prepared by standard focused ion beam (FIB) milling. The overlayers in all images herein were fabricated in the presence of 1 g L-1 PGlu.

The granular nature of the overlayer also hints at the relatively high polymer contents in the hybrid. The TGA measurement indicates that the thin coating has a considerable polymer content of 9.93 ± 1.29 wt% (N = 7). Taking into account that the overlayer takes up a vast majority of the whole mass, it is inferred safely that this value is close to the percentage of PGlu occluded in the overlayer. The granular nature of spherulitic microdomains caused by the PGlu occlusion implies that the overlayer can exhibit toughness to some degree.12, 47, 48 This information is particularly important when the recipe is employed to deposit such a thin layer on a curved substrate, where stress can be largely released. This issue will be discussed further below in this manuscript.

We emphasize that the presence of a continuous seed layer is critical for the deposition of the mineralized overlayer uniformly across the macroscopic distance. A comparison test confirmed that CaCO3 mineralization occurring on the chitosan thin film in the presence of PGlu led to sporadic polycrystalline domains, which highlights the crucial role of the seed layer in achieving a continuous overlayer (Figure 2a-b).


Langmuir 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 41

Figure 2. Results of the CaCO3-PGlu deposition on the chitosan substrate instead of the seed layer. POM (a) and SEM (b) images showing that a discontinuous thin film was obtained in the absence of the seed layer.

Moreover, the polymer additive also played a profound role in regulating the structural character of the overlayer. In a typical seeded mineralization, employment of a variable amount of PGlu in the overgrowth caused different morphological characteristics of the exterior texture. The low concentration level of PGlu (i.e. [PGlu] = 0.1 g L-1) led to the appearance of numerous exterior rhombohedral facets (Figure 3a). As a comparison, spherulitic microdomains composed of granular constituents were obtained in the presence of 1 g L-1 PGlu (Figure 3b). The structural differences can be attributed to the inhibition effect of the polyanionic additive,49 which demonstrates that a particle-involved mineralization pathway50 leads to crystalline products possessing a mesoscopic texture with a rough surface.51-53 Further increase of the PGlu concentration (i.e. [PGlu] = 5 g L-1) induced the growth of multiple nanoneedles on each microdomain (Figure 3c). Appearance of protruding nanofibers on growing crystals was 14 ACS Paragon Plus Environment

Page 15 of 41 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

Langmuir

observed in previous studies of bio-inspired mineralization.33, 54, 55 Their appearance can be assumedly attributed to secondary nucleation on the as-formed overlayer.

Figure 3. Additive effect on the morphological control of the exterior textures of overlayers. a-c, SEM images show the concentration effect of PGlu, where the calcite CaCO3 overlayers were obtained in the presence of 0.1 g L-1 (a), 1.0 g L-1 (b), and 5.0 g L-1 (c) PGlu, respectively. d-e, SEM images show distinct exterior textures of the overlayers obtained in the presence of different additives, namely, SF (d) and PSS (e) (i.e. [Additive] = 1 g L-1 in each case study). f, SEM image showing that the deposition of CaCO3 in the absence of a polymer additive leads to sporadic rhombohedral calcite crystals on the seed layer. Crucially, employment of different polymer additives15, 59 caused a significant morphological difference in the exterior textures on each microdomain (Figure. S3a-h). For example, the presence of silk fibroin (SF; purified from the larvae of Bombyx mori) and poly(styrene sulfonate) 15 ACS Paragon Plus Environment

Langmuir 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

sodium salt (PSS) led to the block-shaped and crossed-lamellar exterior textures, respectively (Figure 3d-e). For instance, mineralization in the presence of PSS led to microdomains composed of laterally aligned lamellae (Figure 3e). Nevertheless, adjacent lamellar domains are randomly oriented due to the absence of the lateral guidance in the seed layer. Such lamellar texture was also found in CaCO3 mesocrystals fabricated in the presence of PSS51 or in PSS-containing block copolymers.52 According to a previous study,60 this kind of lamellar-type CaCO3 crystals is obtained due to the specific adsorption of PSS molecules on the (001) surface of growing calcite crystals, which exhibits the inherent Ca2+-rich character. As a comparison, continuous mineralized layers bearing a specific hierarchical architecture could be achieved empirically in numerous studies of one-step bio-inspired mineralization.61-63 It is highly plausible that a typical one-step mineralization process may couple two spontaneous stages: deposition of a continuous granular layer and the subsequent deposition of an overlayer with distinct hierarchical architecture.62 Unlike seeded mineralization, spontaneous mineralization nonetheless lacks the necessary control of the structural character of the overlayer such as uniformity and continuity. Employment of an effective polymer additive in seeded mineralization instead is essential for obtaining a continuous overlayer with the specific hierarchical architecture. It is noteworthy that overgrowth in the absence of a polymer additive only caused sporadic rhombohedral calcite crystals on the seed layer (Figure 3f). Hence, the formation of a continuous overlayer is ascribed to the pre-adsorption of the polymer additives on the seed layer,64 similar to the adsorption of sulfate containing molecules as ion sponge around the carboxylated nucleation 16 ACS Paragon Plus Environment

Page 16 of 41

Page 17 of 41 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

Langmuir

spots in nacre biomineralization,65 which interact with calcium cations and possibly precursor phases such as clusters and amorphous nanoparticles, aiming for enhancing the nucleation number density.

Interestingly, the hierarchical overlayer supported repetitive seeded mineralization to generate spatial structural heterogeneity between adjacent overlayers exhibiting distinct hierarchical architectures. For instance, a block-shaped calcite-SF overlayer could be deposited on a typical calcite-PGlu layer, where the junction was clearly visible (Figure 4a). In another case study with the same additive, PGlu was employed in consequent overgrowth. The highly decreased PGlu concentration (i.e. [PGlu] = 0.02 g L-1) in the second seeded mineralization caused the continuous coverage of curve-shaped calcite crystals (Figure 4b-c).53 Hence, spatial structural heterogeneity, a crucial character of many biominerals,66 can be implemented via repetitive overgrowth by taking advantage of the concept of seeded mineralization. In short, multi-layered coatings composed of distinct hierarchical architectures could be obtained by using repetitive seeded mineralization.


Langmuir 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 41

Figure 4. a, Consecutive growth of the second CaCO3-SF overlayer by using the CaCO3-PGlu overlayer (i.e. [PGlu] = 1 g L-1) as the “seed” layer, where the interface is clearly visible. b-c, CaCO3-PGlu overlayer (i.e. [PGlu] = 1 g L-1) as the “seed” for growth of a CaCO3 thin film in the presence of 0.02 g L-1 PGlu, where multiple calcitic (104) facets are exposed. The exterior hierarchical architecture of the calcite-PGlu overlayer (i.e. [PGlu] = 1 g L-1) exhibited excellent underwater superoleophobicity and ultralow adhesion force of oil in water. For instance, the responding contact angle and adhesion force of an oil droplet (1,2-dichloroethane, 3 µL) in water are 170.1 ± 2.6° and 25 µN (N = 3), respectively (Figure 5a). 18 ACS Paragon Plus Environment

Page 19 of 41 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

Langmuir

Moreover, the sliding angle of an oil droplet in water is as low as 2.1 ± 0.6° (N = 3) (Figure 5b). It is evident that when the overlayer tilts slightly under water, the oil droplet immediately rolls

Figure 5. Wetting behavior of different oils on the CaCO3-PGlu overlayer [PGlu] = 1 g L-1. a-b, Photographs of an oil droplet (1,2-dichloroethane, 3 µL) sitting on the overlayer with the static 19 ACS Paragon Plus Environment

Langmuir 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 41

contact angle of 170.1° ± 2.6° (a) and the sliding angle of 2.1° ± 0.6° (b). c, Plot summarizing the under-water superoleophobicity and the adhesion forces of the overlayer to five kinds of oil.

away without residual oil being left on the substrate. Besides, the same overlayer shows the underwater superoleophobicity to a series of oils (density < 1 g L-1), all with contact angles higher than 155° (Figure 5c). It is worth noting that the overlayer has ultralow adhesion to these oil droplets in water with all values less than 20 µN (Figure 5c). This remarkable wetting behavior can be convincingly attributed to the exterior micro-/nano-textures. Hence, the hierarchical CaCO3-PGlu overlayer infiltrated with a thin layer of water has an effective resistance to oil contact.67 As a comparison, the underwater oil contact angles of the (104) facet of calcite and the seed layer are 143.4° ± 2.3° (N=3) and 145.3° ± 1.6°(N=3) (Figure S4a-b). Therefore, the presence of microstructures is essential for the appearance of underwater superoleophobicity, in accordance with current understanding.67 For example, the CaCO3-SF overlayer bearing multiple rhombohedral CaCO3 microcrystals (Figure 3d) exhibits underwater superoleophobicity with the contact angle of 165.3° ± 2.1° (N=3) (Figure S4c). It is important to note that bottom-up methods based on the oriented assembly of shape-anisotropic nanoparticles68 or mineralization31, 69 have been employed for fabrication of robust coatings with under-water superoleophobicity. For example, Xu et al. designed a robust, nacreous-type clay-polymer hybrid, which exhibited under-water superoleophobicity.68 Nevertheless, the layer-by-layer assembly is a time-consuming approach with a limited selection pool of polymeric candidates. 20 ACS Paragon Plus Environment

Page 21 of 41 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

Langmuir

Alternatively, a mineralization method was employed for fabrication of a mineral-doped microporous polypropylene membrane.31, 69 Although the hybrid material exhibiting underwater superoleophobicity had a good performance in water-oil separation, it is unlikely that a thin CaCO3 layer could be deposited homogeneously on the fibers of thePAA-modified microporous polypropylene membrane. Instead, CaCO3 nanoprecipitates were either glued onto the polymeric matrix or dispersed in the membrane, which may deteriorate the long-term stability of the hybrid membranes. As a comparison, seeded mineralization studied herein resulted in a continuous, robust overlayer with good adhesion to the substrate.

From the practical point of view, design of robust coatings with underwater superoleophobicity is preferred to withstand mechanical damage. Unlike existing underwater superoleophobic coatings composed mainly of soft materials,36, 38-41 the prismatic-type CaCO3-PGlu overlayers exhibit remarkable hardness and Young's modulus due to their high crystallinity and the presence of the hierarchical architecture. For instance, a typical overlayer (i.e. [PGlu] = 1 g L-1) has a hardness (H) and Young's modulus (E) of 1.45 ± 0.46 GPa and 32.1 ± 9.0 GPa (N = 28), respectively, according to nanoindentation measurements (Figure 6 & Figure S5). Both H and E values of the synthetic thin coatings are comparable with those of biogenic prismatic-type minerals found in mollusk shells, which are in the range of 1-4 and 10-40 Gpa, respectively.70, 71 Moreover, the value of the elastic strain to failure (i.e. H3/E2 = 2.96 MPa) confirms that the overlayer is characteristic of moderate toughness, which is helpful for 21 ACS Paragon Plus Environment

Langmuir 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 41

escaping the appearance of structural defects such as cracks in the overlayer. As a comparison, the H and E values of geologic calcite crystal are 0.4-2.8 GPa and 73.5-85 GPa, respectively.72, 73 The reduction of both values in the synthetic prismatic overlayer can be convincingly attributed to its granular nature. Overall, the mechanical properties of the overlayer demonstrate that the employment of a proper amount of polymer additive in seeded mineralization is fundamental to the specific hierarchical architecture and the related mechanical properties. The remarkable mechanical properties distinguish our synthetic mineralized layer from the existing ones used for oil/water separation based on hydrogels,36, 40, 41 polymers,38, 39 or assemblies of shape-anisotropic colloids68 with moderate mechanical properties.


Page 23 of 41 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

Langmuir

Figure 6. Ashby plot of the prismatic-type CaCO3 thin film and other materials. The dashed lines are ratios of hardness and Young’s modulus as an empirical indentation of toughness. The green dot represents the mechanical properties of the overlayers deposited in the presence of 1 g L-1 PGlu.

To become a candidate for oil/water separation applications, a crack-free coating needs to be deposited on a fibrous substrate with good adhesion. A continuous seed layer could be readily deposited on a glass, nylon, or metal fiber, taking advantage of its granular nature. Next and importantly, the recipe for the deposition of a CaCO3-PGlu overlayer (i.e. [PGlu] = 1 g L-1) on a 23 ACS Paragon Plus Environment

Langmuir 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 24 of 41

planar substrate can be readily employed for the seeded mineralization of a crack-free overlayer on a fibrous substrate. An example shows that a continuous prismatic-type overlayer composed of densely-packed spherulitic microdomains could be deposited on a thin glass fiber (i.e. diameter = 200 µm) (Figure. 7a-b). An exemplary SEM image shows the presence of a seamless interface between the fan-shaped polydomains and the seed layer underneath (Figure 7c-d). Importantly, no crack appears in adjacent microdomains. It is noteworthy to stress that biogenic mineralized thin films are deposited on a curved substrate instead of a planar one. For instance, biogenic prismatic- type minerals found in mollusk shells are moderately-curved, where stress can be released by the existence of organic matrices between adjacent prisms.74 As a comparison, the synthetic prismatic-type minerals in the current study could be deposited as a crack-free thin film on fibers as thin as 200 µm, where stress is largely released in the overlayer composed of radially-aligned granular structural subunits in each spherulitic microdomain. To our understanding, the newly-exploited seeded mineralization provided the first reliable mineralization method to deposit robust, continuous thin coatings with a specific hierarchical architecture on a fiber – a kind of highly curved substrate.


Page 25 of 41 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

Langmuir


Langmuir 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 26 of 41

Figure 7. Deposition of the prismatic-type CaCO3-PGlu overlayer ([PGlu] = 1 g L-1) on a fibrous substrate and oil-water separation test with a nylon mesh modified with a uniform mineralized coating. a, OM image of a bare glass fiber (upper) and the fiber coated with a mineralized layer (lower). b-d, SEM images showing the overview (b) and structural details (c-d) of a mineralized coating, where the arrow in image c points to the interface between the seed layer and the overlayer. d, Superstructure composed of radially-aligned granular structural subunits in spherulitic microdomains. e, Chart showing the content of residual oil in the filtrate for a series of oils, and the insets showing the separation process.

Based on the excellent underwater superoleophobicity and ultralow adhesion force to oils, a nylon mesh coated with a uniform prismatic-type CaCO3-PGlu overlayer exhibited excellent oil/water separation performance when dealing with a series of mixtures of water and different oils (Figure 7e). When the mixtures were poured onto the mesh, water could pass through the mesh quickly by gravity merely, leaving oil droplets on top of the mesh. No visible oil was detected in the collected water after the separation. Separation efficiency evaluated by the oil content in the collected water confirms that the concentration of the remaining oil in each water sampling was less than 4 ppm. Moreover, the mineralized mesh could be used repeatedly, as the ultralow adhesion force of the mesh means the residual oil on the mesh could be easily washed away by water. Our bio-inspired coating provides a cheap, robust, and green alternative to current coating systems for the oil/water separation. 26 ACS Paragon Plus Environment

Page 27 of 41 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

Langmuir

CONCLUSIONS

Seeded mineralization inspired by spatial structural heterogeneity found in biominerals provides a controllable mineralization method for the fabrication of continuous hierarchical CaCO3 thin films with stiffness/strength and the appearance of superwetting behavior. Remarkably, the seed layer acts as a versatile platform for the morphosyntheses of distinct hierarchical micro-/nano-textures in the presence of different polymer additives. This robust mineralized thin coating obtained under proper mineralization conditions can be deposited on fibrous substrates, which significantly expands the application opportunities of this controllable mineralization method. One example is oil/water separation. The bio-inspired approach based on seed mineralization could be extended to the fabrication of other multifunctional coatings, combining the inherent properties of the (in)organic constituents with emerging structural functions.

ASSOCIATED CONTENT

Supporting Information

The Supporting Information is available free of charge on the ACS Publications website

Supplementary figures (Figure S1-S6)

AUTHOR INFORMATION


Langmuir 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 28 of 41

Corresponding Author *E-mail: [email protected]

*E-mail: [email protected]

*E-mail: [email protected]

Author Contributions [+]

These authors contributed equally to this work.

Notes The authors declare no competing financial interest.

ACKNOWLEDGMENT Y.J. acknowledges financial support from the National Natural Science Foundation of China (NSFC; 21303144) and Science Foundation of the Fujian Province, China (2014J01207). S.-H.Y acknowledges the funding support from NSFC (21431006, 21761132008). S.W thanks the National Natural Science Foundation of China (21425314, 21434009, and 21421061), the Top-Notch Young Talents Program of China. X.Y.L thanks NSFC (U1405226), the “111” Project (B16029), Fujian Provincial Bureau of Science & Technology (2014H6022), and the 1000 Talents Program from Xiamen University. Prof. Dongtao Ge, Drs. Yanmei Zhang & Likun Yang, Xinyu Liu, Yuan He, Kun Zhou, and Zihao Lu are acknowledged for characterization assistance and discussions. 28 ACS Paragon Plus Environment

Page 29 of 41 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

Langmuir

REFERENCES 1. Fratzl, P.; Weinkamer, R., Nature's Hierarchical Materials. Prog. Mater. Sci. 2007, 52, 1263-1334.

2. Meyers, M. A.; McKittrick, J.; Chen, P.-Y., Structural Biological Materials: Critical Mechanics-Materials Connections. Science 2013, 339, 773-779.

3. Ritchie, R. O., The Conflicts between Strength and Toughness. Nat. Mater. 2011, 10, 817-822.

4. Weinkamer, R.; Fratzl, P., Solving Conflicting Functional Requirements by Hierarchical Structuring—Examples from Biological Materials. MRS Bull. 2016, 41, 667-671.

5. Jackson, A. P.; Vincent, J. F. V.; Turner, R. M., The Mechanical Design of Nacre. Proc. R. Soc. London, Ser. B 1988, 234, 415-440.

6. Yao, H. B.; Ge, J.; Mao, L. B.; Yan, Y. X.; Yu, S. H., 25th Anniversary Article: Artificial Carbonate Nanocrystals and Layered Structural Nanocomposites Inspired by Nacre: Synthesis, Fabrication and Applications. Adv. Mater. 2014, 26, 163-188.

7. Aksay, I. A.; Trau, M.; Manne, S.; Honma, I.; Yao, N.; Zhou, L.; Fenter, P.; Eisenberger, P. M.; Gruner, S. M., Biomimetic Pathways for Assembling Inorganic Thin Films. Science 1996, 273, 892-898.


Langmuir 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 30 of 41

8. Kato, T., Polymer/Calcium Carbonate Layered Thin-Film Composites. Adv. Mater. 2000, 12, 1543-1546.

9. Kato, T.; Sugawara, A.; Hosoda, N., Calcium Carbonate–Organic Hybrid Materials. Adv. Mater. 2002, 14, 869-877.

10.

Sommerdijk, N.; de With, G., Biomimetic CaCO3 Mineralization using Designer

Molecules and Interfaces. Chem. Rev. 2008, 108, 4499-4550.

11.

Kato, T.; Sakamoto, T.; Nishimura, T., Macromolecular Templating for the Formation

of Inorganic-Organic Hybrid Structures. MRS Bull. 2010, 35, 127-132.

12.

Natalio, F.; Corrales, T. P.; Panthöfer, M.; Schollmeyer, D.; Lieberwirth, I.; Müller, W.

E. G.; Kappl, M.; Butt, H.-J.; Tremel, W., Flexible Minerals: Self-Assembled Calcite Spicules with Extreme Bending Strength. Science 2013, 339, 1298-1302.

13.

Sun, S.; Mao, L.-B.; Lei, Z.; Yu, S.-H.; Cölfen, H., Hydrogels from Amorphous

Calcium Carbonate and Polyacrylic Acid: Bio-Inspired Materials for “Mineral Plastics”. Angew. Chem. Int. Ed. 2016, 55, 11765-11769.

14.

Xiao, C.; Li, M.; Wang, B.; Liu, M.-F.; Shao, C.; Pan, H.; Lu, Y.; Xu, B.-B.; Li, S.;

Zhan, D.; Jiang, Y.; Tang, R.; Liu, X. Y.; Cölfen, H., Total Morphosynthesis of Biomimetic Prismatic-Type CaCO3 Thin Films. Nat. Commun. 2017, 8, No. 1398. 30 ACS Paragon Plus Environment

Page 31 of 41 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

Langmuir

15.

Meldrum, F. C.; Cölfen, H., Controlling Mineral Morphologies and Structures in

Biological and Synthetic Systems. Chem. Rev. 2008, 108, 4332-4432.

16.

Falini, G.; Albeck, S.; Weiner, S.; Addadi, L., Control of Aragonite or Calcite

Polymorphism by Mollusk Shell Macromolecules. Science 1996, 271, 67-69.

17.

Falini, G.; Fermani, S.; Gazzano, M.; Ripamonti, A., Oriented Crystallization of

Vaterite in Collagenous Matrices. Chem. Eur. J. 1998, 4, 1048-1052.

18.

Hosoda, N.; Kato, T., Thin-Film Formation of Calcium Carbonate Crystals: Effects of

Functional Groups of Matrix Polymers. Chem. Mater. 2001, 13, 688-693.

19.

Hosoda, N.; Sugawara, A.; Kato, T., Template Effect of Crystalline Poly(vinyl alcohol)

for Selective Formation of Aragonite and Vaterite CaCO3 Thin Films. Macromolecules 2003, 36, 6449-6452.

20.

Sugawara, A.; Nishimura, T.; Yamamoto, Y.; Inoue, H.; Nagasawa, H.; Kato, T.,

Self-Organization of Oriented Calcium Carbonate/Polymer Composites: Effects of a Matrix Peptide Isolated from the Exoskeleton of a Crayfish. Angew. Chem. Int. Ed. 2006, 45, 2876-2879.


Langmuir 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

21.

Page 32 of 41

Suzuki, M.; Oaki, Y.; Imai, H., Aragonite Nanorod Arrays through Molecular

Controlled Growth on Single-Crystalline Substrate and Polysaccharide Surface. Cryst. Growth Des. 2016, 16, 3741-3747.

22.

Oaki, Y.; Kajiyama, S.; Nishimura, T.; Imai, H.; Kato, T., Nanosegregated Amorphous

Composites of Calcium Carbonate and an Organic Polymer. Adv. Mater. 2008, 20, 3633-3637.

23.

Gebauer, D.; Oliynyk, V.; Salajkova, M.; Sort, J.; Zhou, Q.; Bergstrom, L.;

Salazar-Alvarez, G., A Transparent Tybrid of Nanocrystalline Cellulose and Amorphous Calcium Carbonate Nanoparticles. Nanoscale 2011, 3, 3563-3566.

24.

Volkmer, D.; Harms, M.; Gower, L.; Ziegler, A., Morphosynthesis of Nacre-Type

Laminated CaCO3 Thin Films and Coatings. Angew. Chem. Int. Ed. 2005, 44, 639-644.

25.

Malinova, K.; Gunesch, M.; Pancera, S. M.; Wengeler, R.; Rieger, B.; Volkmer, D.,

Production of CaCO3/Hyperbranched Polyglycidol Hybrid Films Using Spray-Coating Technique. J. Colloid Interface Sci. 2012, 374, 61-69.

26.

Mao, L.-B.; Gao, H.-L.; Yao, H.-B.; Liu, L.; Cölfen, H.; Liu, G.; Chen, S.-M.; Li, S.-K.;

Yan, Y.-X.; Liu, Y.-Y.; Yu, S.-H., Synthetic Nacre by Predesigned Matrix-Directed Mineralization. Science 2016, 354, 107-110.


Page 33 of 41 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

Langmuir

27.

Lakshminarayanan, R.; Valiyaveettil, S.; Loy, G. L., Selective Nucleation of Calcium

Carbonate Polymorphs: Role of Surface Functionalization and Poly(Vinyl Alcohol) Additive. Cryst. Growth Des. 2003, 3, 953-958.

28.

Kim, I. W.; DiMasi, E.; Evans, J. S., Identification of Mineral Modulation Sequences

within the Nacre-Associated Oyster Shell Protein, n16. Cryst. Growth Des. 2004, 4, 1113-1118.

29.

Fu, G.; Valiyaveettil, S.; Wopenka, B.; Morse, D. E., CaCO3 Biomineralization: Acidic

8-kDa Proteins Isolated from Aragonitic Abalone Shell Nacre Can Specifically Modify Calcite Crystal Morphology. Biomacromolecules 2005, 6, 1289-1298.

30.

Ajikumar, P. K.; Lakshminarayanan, R.; Valiyaveettil, S., Controlled Deposition of

Thin Films of Calcium Carbonate on Natural and Synthetic Templates. Cryst. Growth Des. 2004, 4, 331-335.

31.

Chen, P. C.; Wan, L. S.; Xu, Z. K., Bio-Inspired CaCO3 Coating for Superhydrophilic

Hybrid Membranes with High Water Permeability. J. Mater. Chem. 2012, 22, 22727-22733.

32.

Cheng, C.; Yang, Y.; Chen, X.; Shao, Z., Templating Effect of Silk Fibers in the

Oriented Deposition of Aragonite. Chem. Commun. 2008, 0, 5511-5513.


Langmuir 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

33.

Page 34 of 41

Liu, L.; He, D.; Wang, G.-S.; Yu, S.-H., Bioinspired Crystallization of CaCO3 Coatings

on Electrospun Cellulose Acetate Fiber Scaffolds and Corresponding CaCO3 Microtube Networks. Langmuir 2011, 27, 7199-7206.

34.

Burazerovic, S.; Gradinaru, J.; Pierron, J.; Ward, T. R., Hierarchical Self-Assembly of

One-Dimensional Streptavidin Bundles as a Collagen Mimetic for the Biomineralization of Calcite. Angew. Chem. Int. Ed. 2007, 119, 5606-5610.

35.

Liu, M.; Wang, S.; Wei, Z.; Song, Y.; Jiang, L., Bioinspired Design of a

Superoleophobic and Low Adhesive Water/Solid Interface. Adv. Mater. 2009, 21, 665-669.

36.

Xue, Z. X.; Wang, S. T.; Lin, L.; Chen, L.; Liu, M. J.; Feng, L.; Jiang, L., A Novel

Superhydrophilic and Underwater Superoleophobic Hydrogel-Coated Mesh for Oil/Water Separation. Adv. Mater. 2011, 23, 4270-4273.

37.

Zhang, L. B.; Zhang, Z. H.; Wang, P., Smart Surfaces with Switchable

Superoleophilicity and Superoleophobicity in Aqueous Media: Toward Controllable Oil/Water Separation. NPG Asia Mater. 2012, 4, No. e8.

38.

Gao, X. F.; Xu, L. P.; Xue, Z. X.; Feng, L.; Peng, J. T.; Wen, Y. Q.; Wang, S. T.;

Zhang, X. J., Dual-Scaled Porous Nitrocellulose Membranes with Underwater Superoleophobicity for Highly Efficient Oil/Water Separation. Adv. Mater. 2014, 26, 1771-1775.


Page 35 of 41 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

Langmuir

39.

Zhang, W. B.; Zhu, Y. Z.; Liu, X.; Wang, D.; Li, J. Y.; Jiang, L.; Jin, J., Salt-Induced

Fabrication of Superhydrophilic and Underwater Superoleophobic PAA-g-PVDF Membranes for Effective Separation of Oil-in-Water Emulsions. Angew. Chem. Int. Ed. 2014, 53, 856-860.

40.

Cai, Y.; Lu, Q. H.; Guo, X. L.; Wang, S. T.; Qiao, J. L.; Jiang, L., Salt-Tolerant

Superoleophobicity on Alginate Gel Surfaces Inspired by Seaweed (Saccharina japonica). Adv. Mater. 2015, 27, 4162-4168.

41.

Fan, J. B.; Song, Y. Y.; Wang, S. T.; Meng, J. X.; Yang, G.; Guo, X. L.; Feng, L.; Jiang,

L., Directly Coating Hydrogel on Filter Paper for Effective Oil-Water Separation in Highly Acidic, Alkaline, and Salty Environment. Adv. Funct. Mater. 2015, 25, 5368-5375.

42.

Lakshminarayanan, R.; Chi-Jin, E. O.; Loh, X. J.; Kini, R. M.; Valiyaveettil, S.,

Purification and Characterization of a Vaterite-Inducing Peptide, Pelovaterin, from the Eggshells of Pelodiscus Sinensis (Chinese Soft-Shelled Turtle). Biomacromolecules 2005, 6, 1429-1437.

43.

Nys, Y.; Gautron, J.; Garcia-Ruiz, J. M.; Hincke, M. T., Avian Eggshell Mineralization:

Biochemical and Functional Characterization of Matrix Proteins. C. R. Palevol 2004, 3, 549-562.

44.

Checa, A. G.; Rodrı́guez-Navarro, A. B., Self-Organisation of Nacre in the Shells of

Pterioida (Bivalvia: Mollusca). Biomaterials 2005, 26, 1071-1079.


Langmuir 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

45.

Page 36 of 41

Gilbert, P. U. P. A.; Metzler, R. A.; Zhou, D.; Scholl, A.; Doran, A.; Young, A.; Kunz,

M.; Tamura, N.; Coppersmith, S. N., Gradual Ordering in Red Abalone Nacre. J. Am. Chem. Soc. 2008, 130, 17519-17527.

46.

Bayerlein, B.; Zaslansky, P.; Dauphin, Y.; Rack, A.; Fratzl, P.; Zlotnikov, I.,

Self-Similar Mesostructure Evolution of the Growing Mollusc Shell Reminiscent of Thermodynamically Driven Grain Growth. Nat. Mater. 2014, 13, 1102-1107.

47.

Pokroy, B.; Fitch, A. N.; Marin, F.; Kapon, M.; Adir, N.; Zolotoyabko, E., Anisotropic

Lattice Distortions in Biogenic Calcite Induced by Intra-Crystalline Organic Molecules. J. Struct. Biol. 2006, 155, 96-103.

48.

Kim, Y.-Y.; Ganesan, K.; Yang, P.; Kulak, A. N.; Borukhin, S.; Pechook, S.; Ribeiro,

L.; Kröger, R.; Eichhorn, S. J.; Armes, S. P.; Pokroy, B.; Meldrum, F. C., An Artificial Biomineral formed by Incorporation of Copolymer Micelles in Calcite Crystals. Nat. Mater. 2011, 10, 890-896.

49.

Gebauer, D.; Cölfen, H.; Verch, A.; Antonietti, M., The Multiple Roles of Additives in

CaCO3 Crystallization: A Quantitative Case Study. Adv. Mater. 2009, 21, 435-439.

50.

De Yoreo, J. J.; Gilbert, P. U.; Sommerdijk, N. A.; Penn, R. L.; Whitelam, S.; Joester,

D.; Zhang, H.; Rimer, J. D.; Navrotsky, A.; Banfield, J. F., Crystallization by Particle


Page 37 of 41 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

Langmuir

Attachment in Synthetic, Biogenic, and Geologic Environments. Science 2015, 349, No. aaa6760.

51.

Wang, T. X.; Cölfen, H.; Antonietti, M., Nonclassical Crystallization: Mesocrystals and

Morphology Change of CaCO3 Crystals in the Presence of a Polyelectrolyte Additive. J. Am. Chem. Soc. 2005, 127, 3246-3247.

52.

Kulak, A. N.; Iddon, P.; Li, Y. T.; Armes, S. P.; Cölfen, H.; Paris, O.; Wilson, R. M.;

Meldrum, F. C., Continuous Structural Evolution of Calcium Carbonate Particles: A Unifying Model of Copolymer-Mediated Crystallization. J. Am. Chem. Soc. 2007, 129, 3729-3736.

53.

Song, R. Q.; Xu, A. W.; Antonietti, M.; Cölfen, H., Calcite Crystals with Platonic

Shapes and Minimal Surfaces. Angew. Chem. Int. Ed. 2009, 48, 395-399.

54.

Gower, L. B.; Odom, D. J., Deposition of Calcium Carbonate Films by a

Polymer-Induced Liquid-Precursor (PILP) Process. J. Cryst. Growth 2000, 210, 719-734.

55.

Schenk, A. S.; Cantaert, B.; Kim, Y.-Y.; Li, Y.; Read, E. S.; Semsarilar, M.; Armes, S.

P.; Meldrum, F. C., Systematic Study of the Effects of Polyamines on Calcium Carbonate Precipitation. Chem. Mater. 2014, 26, 2703-2711.

56.

Gower, L. A.; Tirrell, D. A., Calcium Carbonate Films and Helices Grown in Solutions

of Poly(aspartate). J. Cryst. Growth 1998, 191, 153-160.


Langmuir 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

57.

Page 38 of 41

Kim, Y.-Y.; Kulak, A. N.; Li, Y.; Batten, T.; Kuball, M.; Armes, S. P.; Meldrum, F. C.,

Substrate-Directed Formation of Calcium Carbonate Fibres. J. Mater. Chem. 2009, 19, 387-398.

58.

Cantaert, B.; Verch, A.; Kim, Y.-Y.; Ludwig, H.; Paunov, V. N.; Kroeger, R.; Meldrum,

F. C., Formation and Structure of Calcium Carbonate Thin Films and Nanofibers Precipitated in the Presence of Poly(Allylamine Hydrochloride) and Magnesium Ions. Chem. Mater. 2013, 25, 4994-5003.

59.

Yu, S.-H.; Colfen, H., Bio-inspired Crystal Morphogenesis by Hydrophilic Polymers. J.

Mater. Chem. 2004, 14, 2124-2147.

60.

Wang, T.; Antonietti, M.; Cölfen, H., Calcite Mesocrystals: “Morphing” Crystals by a

Polyelectrolyte. Chem. Eur. J. 2006, 12, 5722-5730.

61.

Busch, S.; Dolhaine, H.; DuChesne, A.; Heinz, S.; Hochrein, O.; Laeri, F.; Podebrad,

O.; Vietze, U.; Weiland, T.; Kniep, R., Biomimetic Morphogenesis of Fluorapatite-Gelatin Composites: Fractal Growth, the Question of Intrinsic Electric Fields, Core/Shell Assemblies, Hollow Spheres and Reorganization of Denatured Collagen. Eur. J. Inorg. Chem. 1999, 10, 1643-1653.

62.

Sakamoto, T.; Oichi, A.; Oaki, Y.; Nishimura, T.; Sugawara, A.; Kato, T.,

Three-Dimensional Relief Structures of CaCO3 Crystal Assemblies Formed by Spontaneous Two-Step Crystal Growth on a Polymer Thin Film. Cryst. Growth Des. 2009, 9, 622-625. 38 ACS Paragon Plus Environment

Page 39 of 41 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

Langmuir

63.

Wang, S.-S.; Picker, A.; Cölfen, H.; Xu, A.-W., Heterostructured Calcium Carbonate

Microspheres with Calcite Equatorial Loops and Vaterite Spherical Cores. Angew. Chem. Int. Ed. 2013, 52, 6317-6321.

64.

Addadi, L.; Moradian-Oldak, J.; Weiner, S., Molecule-Crystal Recognition in

Biomineralization: Studies Using Synthetic Polycarboxylate Analogs. ACS Symp. Ser. 1991, 444, 13-27.

65.

Addadi, L.; Joester, D.; Nudelman, F.; Weiner, S., Mollusk Shell Formation: a Source of

New Concepts for Understanding Biomineralization Processes. Chem. Eur. J. 2006, 12, 980-987.

66.

Studart, A. R., Biological and Bioinspired Composites with Spatially Tunable

Heterogeneous Architectures. Adv. Funct. Mater. 2013, 23, 4423-4436.

67.

Su, B.; Tian, Y.; Jiang, L., Bioinspired Interfaces with Superwettability: From Materials

to Chemistry. J. Am. Chem. Soc. 2016, 138, 1727-1748.

68.

Xu, L. P.; Peng, J. T.; Liu, Y. B.; Wen, Y. Q.; Zhang, X. J.; Jiang, L.; Wang, S. T.,

Nacre-Inspired Design of Mechanical Stable Coating with Underwater Superoleophobicity. ACS Nano 2013, 7, 5077-5083.


Langmuir 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

69.

Page 40 of 41

Chen, P. C.; Xu, Z. K., Mineral-Coated Polymer Membranes with Superhydrophilicity

and Underwater Superoleophobicity for Effective Oil/Water Separation. Sci. Rep. 2013, 3, 2776-2781.

70.

Taylor, J. D.; Layman, M., The Mechanical Properties of Bivalve (Mollusca) Shell

Structures. Palaeontology 1972, 15, 73-87.

71.

Currey, J. D.; Taylor, J. D., The Mechanical Behaviour of Some Molluscan Hard

Tissues. J. Zool. 1974, 173, 395-406.

72.

Broz Margaret, E.; Cook Robert, F.; Whitney Donna, L., Microhardness, Toughness,

and Modulus of Mohs Scale Minerals. Am. Mineral., 2006, 91, 135-142.

73.

Ma, Y.; Cohen, S. R.; Addadi, L.; Weiner, S., Sea Urchin Tooth Design: An

“All-Calcite” Polycrystalline Reinforced Fiber Composite for Grinding Rocks. Adv. Mater. 2008, 20, 1555-1559.

74.

Kunitake, M. E.; Mangano, L. M.; Peloquin, J. M.; Baker, S. P.; Estroff, L. A.,

Evaluation of Strengthening Mechanisms in Calcite Single Crystals from Mollusk Shells. Acta Biomater. 2013, 9, 5353-5359.


Page 41 of 41 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

Langmuir

Table of Contents

Seeded Mineralization Leads to Hierarchical CaCO3 Thin Coatings for Oil-Water Separation Applications


Seeded Mineralization Leads to Hierarchical CaCO3 Thin Coatings on

Recommend Documents