Bioinspired Compartmentalization Strategy for Coating Polymers with Self-Organized Prismatic Films

Zheng-Zheng Li,Yu-Xuan Feng,Peter Fratzl,Qi-Qi Huang,Ming Li,Yuan Jiang,Zihao Lu,Hai-Long Wang,Yue-E Wen,Helmut Cölfen,Zhisen Zhang,Hua Bai,Shahrouz Amini,Bin-Bin Xu

doi:10.1021/acs.chemmater.1c02868

Abstract

Biomineralization provides load-bearing and protective functions to living organisms by reinforcing soft tissues. Translation of biomineralization principles to materials science in a controlled and self-organized fashion is highly desirable but challenging. A major lesson from natural systems is that crystallization may be controlled by compartmentalization and templating. Here, we develop a crystallization technique based on graphene oxide-mediated compartmentalization and on templating prismatic growth of calcite nanocoatings via control of ionic diffusivity into the microcompartments, which results in a multistage, self-organized crystallization and represents an effective strategy for providing continuous nanocoatings and enhancing the tribological performance of polymeric surfaces under contact stresses. The present research offers a bottom-up approach of using very basic biomineralization principles for the protection of polymeric surfaces, which are of interest for biomedical applications and the fabrication of high-performance functional materials in a sustainable manner.

Highlights

Mechanical protection resistance to contact stresses imposed by external mechanical stimuli has been a central need in the survival of a diverse group of living organisms from minute Arthropoda to gigantic Mammals.[1−3] Mechanistically, materials that possess higher hardness and stiffness exhibit greater resistance to residual deformations and contact damages, a determining factor for the tribological performance of materials.[4]
Tissue hardening has been the evolutionary solution of nature to support this demand and promote the tribological performance and protective function of biological tissues.[5−7] Biomineralization, by far, has been the greatest solution for the enhancement of tribological characteristics of biological materials in which the presence of mineral blocks improves the hardness and elastic modulus of the organic tissues by more than 1 order of magnitude.[7]
Biological hard shields have been frequently deployed at the exterior layer of a variety of mechanically demanding tissues such as biting mouthparts,[8] appendages,[9,10] and cuticle of invertebrates[11,12] and dermal armor of vertebrates,[13,14] which are prone to high contact stresses and tribological damages

Summary

■ INTRODUCTION

Mechanical protection resistance to contact stresses imposed by external mechanical stimuli has been a central need in the survival of a diverse group of living organisms from minute Arthropoda to gigantic Mammals.[1−3] Mechanistically, materials that possess higher hardness and stiffness exhibit greater resistance to residual deformations and contact damages (e.g., penetration, wear, and abrasion), a determining factor for the tribological performance of materials.[4]. Chemical reduction selectively removed hydroxyl and epoxy groups in the hydrophilic framework of GO, resulting in the formation of reduced GO (rGO) carrying relatively large diffusive barriers of Ca2+ permeation.[44] In a comparison test, rGO-covered PVC led to the formation of discontinuous CaCO3 polydomains 1.04 ± 0.05 μm (N = 10) in thickness (Supporting Information Figure S10a,b), which verifies the important role of the cationic permeability of the superimposed layers. Led to the deposition of discontinuous BaCO3 nanocoatings 659.9 ± 60.1 nm (N = 10) in thickness on GO-covered PVC (Supporting Information Figure S12), which was attributed to the relatively large size of Ba2+ that led to a weaker hydration layer and weaker interactions with the oxidation groups of GO.[47,48] These results verify that the compartmentalization characterized by the selective permeation of metal cations through the GO membranes gave rise to the formation of continuous crystalline nanocoatings. The far-field delamination in the coated PVC sample confirmed that a weak adhesion between the coating and PVC was replaced by a strong adhesion between the chitosan and prismatic coatings

■ DISCUSSION

■ ACKNOWLEDGMENTS

■ REFERENCES