scholarly journals From vesicles to materials: bioinspired strategies for fabricating hierarchically structured soft matter

2021 ◽  
Vol 379 (2206) ◽  
pp. 20200338
Author(s):  
Esther Amstad ◽  
Matthew J. Harrington
Keyword(s):  
Soft Matter ◽  
Hierarchical Structures ◽  
Polymeric Materials ◽  
Advanced Materials ◽  
Ambient Conditions ◽  
Theme Issue ◽  
Structured Materials ◽  
Multi Scale ◽  
Condensed Liquid ◽  
Mussel Byssus

Certain organisms including species of mollusks, polychaetes, onychophorans and arthropods produce exceptional polymeric materials outside their bodies under ambient conditions using concentrated fluid protein precursors. While much is understood about the structure-function relationships that define the properties of such materials, comparatively less is understood about how such materials are fabricated and specifically, how their defining hierarchical structures are achieved via bottom-up assembly. Yet this information holds great potential for inspiring sustainable manufacture of advanced polymeric materials with controlled multi-scale structure. In the present perspective, we first examine recent work elucidating the formation of the tough adhesive fibres of the mussel byssus via secretion of vesicles filled with condensed liquid protein phases (coacervates and liquid crystals)—highlighting which design principles are relevant for bio-inspiration. In the second part of the perspective, we examine the potential of recent advances in drops and additive manufacturing as a bioinspired platform for mimicking such processes to produce hierarchically structured materials. This article is part of the theme issue ‘Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)’.

scholarly journals Straightforward and precise approach to replicate complex hierarchical structures from plant surfaces onto soft matter polymer

2018 ◽  
Vol 5 (4) ◽  
pp. 172132 ◽  
Author(s):  
Charchit Kumar ◽  
Vincent Le Houérou ◽  
Thomas Speck ◽  
Holger F. Bohn
Keyword(s):  
Soft Matter ◽  
Hierarchical Structures ◽  
Future Application ◽  
Plant Interactions ◽  
Plant Leaves ◽  
Ambient Conditions ◽  
Low Viscosity ◽  
Surface Microstructures ◽  
Species Specific ◽  
Replication Technique

The surfaces of plant leaves are rarely smooth and often possess a species-specific micro- and/or nano-structuring. These structures usually influence the surface functionality of the leaves such as wettability, optical properties, friction and adhesion in insect–plant interactions. This work presents a simple, convenient, inexpensive and precise two-step micro-replication technique to transfer surface microstructures of plant leaves onto highly transparent soft polymer material. Leaves of three different plants with variable size (0.5–100 µm), shape and complexity (hierarchical levels) of their surface microstructures were selected as model bio-templates. A thermoset epoxy resin was used at ambient conditions to produce negative moulds directly from fresh plant leaves. An alkaline chemical treatment was established to remove the entirety of the leaf material from the cured negative epoxy mould when necessary, i.e. for highly complex hierarchical structures. Obtained moulds were filled up afterwards with low viscosity silicone elastomer (PDMS) to obtain positive surface replicas. Comparative scanning electron microscopy investigations (original plant leaves and replicated polymeric surfaces) reveal the high precision and versatility of this replication technique. This technique has promising future application for the development of bioinspired functional surfaces. Additionally, the fabricated polymer replicas provide a model to systematically investigate the structural key points of surface functionalities.

Biomimetic materials: An introduction

1992 ◽  
Vol 50 (2) ◽  
pp. 1020-1021 ◽  
Author(s):  
M. Sarikaya ◽  
J. T. Staley ◽  
I. A. Aksay
Keyword(s):  
Self Assembly ◽  
Structural Control ◽  
Hierarchical Structures ◽  
Ceramic Composites ◽  
Advanced Materials ◽  
Length Scale ◽  
Spider Webs ◽  
Biomimetic Materials ◽  
Synthetic Materials ◽  
All Ceramic

Biomimetics is an area of research in which the analysis of structures and functions of natural materials provide a source of inspiration for design and processing concepts for novel synthetic materials. Through biomimetics, it may be possible to establish structural control on a continuous length scale, resulting in superior structures able to withstand the requirements placed upon advanced materials. It is well recognized that biological systems efficiently produce complex and hierarchical structures on the molecular, micrometer, and macro scales with unique properties, and with greater structural control than is possible with synthetic materials. The dynamism of these systems allows the collection and transport of constituents; the nucleation, configuration, and growth of new structures by self-assembly; and the repair and replacement of old and damaged components. These materials include all-organic components such as spider webs and insect cuticles (Fig. 1); inorganic-organic composites, such as seashells (Fig. 2) and bones; all-ceramic composites, such as sea urchin teeth, spines, and other skeletal units (Fig. 3); and inorganic ultrafine magnetic and semiconducting particles produced by bacteria and algae, respectively (Fig. 4).

Synthesis of bio-based 2-thiothiophenes

2021 ◽  
Vol 379 (2209) ◽  
pp. 20200350
Author(s):  
Yichen Qiu ◽  
Yunchao Feng ◽  
Ashley C. Lindsay ◽  
Xianhai Zeng ◽  
Jonathan Sperry
Keyword(s):  
Small Molecule ◽  
Chemical Industry ◽  
Emerging Technologies ◽  
Advanced Materials ◽  
Organosulfur Compounds ◽  
Theme Issue ◽  
Widespread Application ◽  
Fossil Carbon ◽  
Functionally Diverse

While the synthesis of bio-based compounds containing carbon, oxygen and (to a lesser extent) nitrogen is well studied, the production of organosulfur compounds from biomass has received virtually no attention, despite their widespread application throughout the chemical industry. Herein, we demonstrate that a range of bio-based 2-thiothiophenes are available from the biopolymer cellulose, proving that functionally diverse small-molecule organosulfurs can be prepared independent of fossil carbon. This article is part of the theme issue ‘Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)’.

Improving photoluminescence, optical and electrical characteristics of PMMA films with gamma irradiation

2021 ◽  
Author(s):  
M.F. Zaki ◽  
Nasser Shubayr ◽  
Reda M Radwan ◽  
Yazeed Alashban
Keyword(s):  
Gamma Irradiation ◽  
Polymeric Materials ◽  
Advanced Materials ◽  
Strong Impact ◽  
Electrical Characteristics ◽  
Electrical Measurements ◽  
Indirect Transition ◽  
Dielectric Parameters ◽  
Vis Spectroscopy ◽  
Gamma Irradiated

Abstract Polymeric materials are macromolecules, essentially a combination of numerous repeated subunits. Polymers are innovative and advanced materials that currently have a strong impact on our daily lives. In recent years, polymer use has been prominent due to the materials’ distinctive properties; thus, they entered different fields of science, technology and industrial-biomedical applications.The improvement of photoluminescence, optical and electrical characteristics of non-conducting Poly(methyl methacrylate) (PMMA) films was studied. Upon gamma irradiation of various doses, the photophysical and electrical properties of PMMA films were investigated using photoluminescence spectroscopy, ultraviolet–visible (UV-Vis) spectroscopy and the LCR Meter Bridge Circuit technique. The fluorescent response improved the photoluminescence (PL) spectral emission peaks according to gamma values. Strong fluorescence peaks appeared with the highest gamma dose. The UV–Vis results revealed a significant red-shift in the absorption edge as gamma doses increased. This shift exhibits a continuous decrease in the energy band gap values (from 3.50 to 2.60 eV for direct transition and from 3.05 to 1.55 eV for indirect transition). This was due to the formation of carbon clusters, which led to an increase in the electrical conductivity and improved the dielectric parameters of the irradiated PMMA films. Among a variety of measurements presented and discussed in the present study, the electrical measurements showed improved electrical characteristics of gamma-irradiated PMMA films.

scholarly journals Rules of collective migration: from the wildebeest to the neural crest

2020 ◽  
Vol 375 (1807) ◽  
pp. 20190387 ◽  
Author(s):  
Adam Shellard ◽  
Roberto Mayor
Keyword(s):  
Neural Crest ◽  
Individual Cell ◽  
Embryonic Stem ◽  
Stem Cell Population ◽  
Scale Analysis ◽  
Collective Migration ◽  
Theme Issue ◽  
Cell Behaviour ◽  
Multi Scale ◽  
Universal Principles

Collective migration, the movement of groups in which individuals affect the behaviour of one another, occurs at practically every scale, from bacteria up to whole species' populations. Universal principles of collective movement can be applied at all levels. In this review, we will describe the rules governing collective motility, with a specific focus on the neural crest, an embryonic stem cell population that undergoes extensive collective migration during development. We will discuss how the underlying principles of individual cell behaviour, and those that emerge from a supracellular scale, can explain collective migration. This article is part of the theme issue ‘Multi-scale analysis and modelling of collective migration in biological systems’.

scholarly journals Oxygen vacancy engineering in spinel-structured nanosheet wrapped hollow polyhedra for electrochemical nitrogen fixation under ambient conditions

2020 ◽  
Vol 8 (4) ◽  
pp. 1652-1659 ◽  
Author(s):  
Feili Lai ◽  
Jianrui Feng ◽  
Xiaobin Ye ◽  
Wei Zong ◽  
Guanjie He ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Oxygen Vacancy ◽  
Ambient Conditions ◽  
Faradaic Efficiency ◽  
Structured Materials ◽  
Ammonia Conversion

Electrochemical nitrogen-to-ammonia conversion under ambient conditions is realized by an oxygen vacancy-rich spinel structured materials, showing relatively high faradaic efficiency and yields.

Deformation and Fracture Characteristics of Cenosphere Filled Epoxies Under Compressive Loading Conditions

2001 ◽  
Author(s):  
Nikhil Gupta ◽  
Eyassu Woldesenbet
Keyword(s):  
Epoxy Resins ◽  
Fracture Behavior ◽  
Moisture Absorption ◽  
Compressive Loading ◽  
Polymeric Materials ◽  
Local Stress ◽  
Fracture Characteristics ◽  
Structured Materials ◽  
Deformation And Fracture

Abstract Close cell structured foams are made by incorporation of cenospheres in polymeric materials. Low moisture absorption characteristics and considerably higher compressive strength of these materials compared to open cell structured foams make them suitable for use as core materials in sandwich structured materials. Incorporation of cenospheres in the epoxy resins enhances their impact strength and damage tolerance, especially if these materials are used in sandwich configurations. Present study analyzes and compares the effect of incorporation of cenospheres like flyash and glass microballoons in the epoxy resins on the deformation and fracture behavior of the material. Approach based on determination of local stress intensity factors is used to obtain estimate of the stresses in the material.

scholarly journals Metals and non-metals in the periodic table

2020 ◽  
Vol 378 (2180) ◽  
pp. 20200213
Author(s):  
Benzhen Yao ◽  
Vladimir L. Kuznetsov ◽  
Tiancun Xiao ◽  
Daniel R. Slocombe ◽  
C. N. R. Rao ◽  
...  
Keyword(s):  
Periodic Table ◽  
Chemical Elements ◽  
Quantum Mechanical ◽  
Great Success ◽  
Ambient Conditions ◽  
Theme Issue ◽  
Atomic Properties ◽  
System A ◽  
Mechanical Approach ◽  
Quantum Mechanical Approach

The demarcation of the chemical elements into metals and non-metals dates back to the dawn of Dmitri Mendeleev's construction of the periodic table; it still represents the cornerstone of our view of modern chemistry. In this contribution, a particular emphasis will be attached to the question ‘Why do the chemical elements of the periodic table exist either as metals or non-metals under ambient conditions?’ This is perhaps most apparent in the p-block of the periodic table where one sees an almost-diagonal line separating metals and non-metals. The first searching, quantum-mechanical considerations of this question were put forward by Hund in 1934. Interestingly, the very first discussion of the problem—in fact, a pre-quantum-mechanical approach—was made earlier, by Goldhammer in 1913 and Herzfeld in 1927. Their simple rationalization, in terms of atomic properties which confer metallic or non-metallic status to elements across the periodic table, leads to what is commonly called the Goldhammer–Herzfeld criterion for metallization. For a variety of undoubtedly complex reasons, the Goldhammer–Herzfeld theory lay dormant for close to half a century. However, since that time the criterion has been repeatedly applied, with great success, to many systems and materials exhibiting non-metal to metal transitions in order to predict, and understand, the precise conditions for metallization. Here, we review the application of Goldhammer–Herzfeld theory to the question of the metallic versus non-metallic status of chemical elements within the periodic system. A link between that theory and the work of Sir Nevill Mott on the metal-non-metal transition is also highlighted. The application of the ‘simple’, but highly effective Goldhammer–Herzfeld and Mott criteria, reveal when a chemical element of the periodic table will behave as a metal, and when it will behave as a non-metal. The success of these different, but converging approaches, lends weight to the idea of a simple, universal criterion for rationalizing the instantly-recognizable structure of the periodic table where … the metals are here, the non-metals are there … The challenge of the metallic and non-metallic states of oxides is also briefly introduced. This article is part of the theme issue ‘Mendeleev and the periodic table’.

scholarly journals Force distribution and multiscale mechanics in the mussel byssus

2019 ◽  
Vol 374 (1784) ◽  
pp. 20190202 ◽  
Author(s):  
Noy Cohen ◽  
J. Herbert Waite ◽  
Robert M. McMeeking ◽  
Megan T. Valentine
Keyword(s):  
Mechanical Response ◽  
Mechanical Performance ◽  
Theoretical Work ◽  
Force Distribution ◽  
Theme Issue ◽  
Byssal Thread ◽  
Multiscale Mechanics ◽  
Dynamic Loadings ◽  
Level Analysis ◽  
Mussel Byssus

The byssi of sessile mussels have the extraordinary ability to adhere to various surfaces and withstand static and dynamic loadings arising from hostile environmental conditions. Many investigations aimed at understanding the unique properties of byssal thread–plaque structures have been conducted and have inspired the enhancement of fibre coatings and adhesives. However, a systems-level analysis of the mechanical performance of the composite materials is lacking. In this work, we discuss the anatomy of the byssus and the function of each of the three components (the proximal thread portion, the distal thread portion and the adhesive plaque) of its structures. We introduce a basic nonlinear system of springs that describes the contribution of each component to the overall mechanical response and use this model to approximate the elastic modulus of the distal thread portion as well as the plaque, the response of which cannot be isolated through experiment alone. We conclude with a discussion of unresolved questions, highlighting areas of opportunity where additional experimental and theoretical work is needed. This article is part of the theme issue ‘Transdisciplinary approaches to the study of adhesion and adhesives in biological systems’.

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