Ultrastrong, Free-Standing and Large Nanofilms of Pyrenearamid

We introduce poly(1,6-pyrene terephthalamide) polymer (PPyrTA) as an aromatic polyamide analogue of poly(p-phenylene terephthalamide) (PPTA), also known as Kevlar®. This work shows that the incorporation of polycyclic aromatic pyrene moieties improves drastically the mechanical properties of the polymeric structure, increasing elastic nanoindentation-determined modulus and hardness by factors of 1.9 and 4.3, respectively. Liquid deprotonated dispersions of PPyrTA nanofibers were used as nanoscale building block for producing large-surface, free-standing polymer macroscopic nanofilms. This 2D assembly leads to further significant improvements in reduced modulus and hardness (more than twice) compared to the starting polymer macroscale fibres, due to a better re-organizational arrangement of the PPyrTA nanofibers in the nanofilms, formed under 2D spatial confinement.

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A reactive molecular dynamics study on the mechanical properties of a recently synthesized amorphous carbon monolayer converted into a nanotube/nanoscroll

Physical Chemistry Chemical Physics ◽

10.1039/d0cp06613c ◽

2021 ◽

Author(s):

Marcelo Lopes Pereira Junior ◽

Wiliam Ferreira da Cunha ◽

Douglas Soares Galvão ◽

Luiz Antonio Ribeiro Junior

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Chemical Vapor Deposition ◽

Amorphous Carbon ◽

Vapor Deposition ◽

Chemical Vapor ◽

Free Standing ◽

Reactive Molecular Dynamics

Recently, laser-assisted chemical vapor deposition has been used to synthesize a free-standing, continuous, and stable monolayer amorphous carbon (MAC).

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Understanding ion-induced assembly of cellulose nanofibrilllar gels through shear-free mixing and in situ scanning-SAXS

Nanoscale Advances ◽

10.1039/d1na00236h ◽

2021 ◽

Author(s):

Tomas Rosén ◽

Ruifu Wang ◽

HongRui He ◽

Chengbo Zhan ◽

Shirish Chodankar ◽

...

Keyword(s):

Mechanical Properties ◽

Building Block ◽

Cellulose Nanofibrils ◽

Advanced Materials ◽

The Past

During the past decade, cellulose nanofibrils (CNFs) have shown tremendous potential as a building block to fabricate new advanced materials that are both biocompatible and biodegradable. The excellent mechanical properties...

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Mechanical strength and flexibility in $$\alpha '$$-4H borophene

Scientific Reports ◽

10.1038/s41598-021-87246-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shobair Mohammadi Mozvashi ◽

Mohammad Ali Mohebpour ◽

Sahar Izadi Vishkayi ◽

Meysam Bagheri Tagani

Keyword(s):

Mechanical Properties ◽

Mechanical Strength ◽

2D Materials ◽

Group Iv ◽

Good Stability ◽

Free Standing ◽

Promising Candidate ◽

Inherent Anisotropy

AbstractVery recently, a novel phase of hydrogenated borophene, namely $$\alpha '$$ α ′ -4H, has been synthesized in a free-standing form. Unlike pure borophenes, this phase shows very good stability in the air environment and possesses semiconducting characteristics. Because of the interesting stiffness and flexibility of borophenes, herein, we systematically studied the mechanical properties of this novel hydrogenated phase. Our results show that the monolayer is stiffer (Y$$_\text {xy}$$ xy = $$\sim $$ ∼ 195 N/m) than group IV and V 2D materials and even than MoS$$_2$$ 2 , while it is softer than graphene. Moreover, similar to other phases of borophene, the inherent anisotropy of the pure monolayer increases with hydrogenation. The monolayer can bear biaxial, armchair, and zigzag strains up to 16, 10, and 14% with ideal strengths of approximately 14, 9, and 12 N/m, respectively. More interestingly, it can remain semiconductor under this range of tension. These outstanding results suggest that the $$\alpha '$$ α ′ -4H is a promising candidate for flexible nanoelectronics.

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Creep and Anisotropy of Free-Standing Lithium Metal Foils in an Industrial Dry Room

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4052043 ◽

2021 ◽

pp. 1-32

Author(s):

Lara Dienemann ◽

Anil Saigal ◽

Michael A Zimmerman

Keyword(s):

Mechanical Properties ◽

Solid State ◽

High Volume ◽

Dominant Mode ◽

Lithium Metal ◽

Free Standing ◽

Metal Anode ◽

Lithium Metal Batteries ◽

Lithium Metal Anode ◽

Solid State Batteries

Abstract Commercialization of energy-dense lithium metal batteries relies on stable and uniform plating and stripping on the lithium metal anode. In electrochemical-mechanical modeling of solid-state batteries, there is a lack of consideration of specific mechanical properties of battery-grade lithium metal. Defining these characteristics is crucial for understanding how lithium ions plate on the lithium metal anode, how plating and stripping affect deformation of the anode and its interfacing material, and whether dendrites are suppressed. Recent experiments show that the dominant mode of deformation of lithium metal is creep. This study measures the time and temperature dependent mechanics of two thicknesses of commercial lithium anodes inside an industrial dry room, where battery cells are manufactured at high volume. Furthermore, a directional study examines the anisotropic microstructure of 100 µm thick lithium anodes and its effect on bulk creep mechanics. It is shown that these lithium anodes undergo plastic creep as soon as a coin cell is manufactured at a pressure of 0.30 MPa, and achieving thinner lithium foils, a critical goal for solid-state lithium batteries, is correlated to anisotropy in both lithium's microstructure and mechanical properties.

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Hierarchical Design and Nanomechanics of the Calcified Byssus of Anomia simplex

MRS Proceedings ◽

10.1557/proc-1187-kk05-09 ◽

2009 ◽

Vol 1187 ◽

Cited By ~ 2

Author(s):

Jakob R Eltzholtz ◽

Marie Krogsgaard ◽

Henrik Birkedal

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Scanning Electron Microscopy ◽

Mechanical Performance ◽

Blue Mussel ◽

Hierarchical Design ◽

Reduced Modulus ◽

Different Types ◽

Microscopy Images ◽

Scanning Electron

AbstractBiology has evolved several strategies for attachment of sedentary animals. In the bivalves, byssi abound and the best known example being the protein-based byssus of the blue mussel and other Mytilidae. In contrast the bivalve Anomia sp. has a single calcified thread. The byssus is hierarchical in design and contains several different types of structures as revealed by scanning electron microscopy images. The mechanical properties of the byssus are probed by nanoindentation. It is found that the mineralized part of the byssus is very stiff with a reduced modulus of about 67 GPa and a hardness of ˜3.7 GPa. This corresponds to a modulus roughly 20% smaller than that of pure calcite and a hardness that is about 20% larger than pure calcite. The results reveal the importance of microstructure on mechanical performance.

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Regiodivergent Biocatalytic Hydroxylation of L-Glutamine Facilitated by Characterization of Non-Heme Dioxygenases from Non-Ribosomal Peptide Biosyntheses

10.26434/chemrxiv.14206172.v1 ◽

2021 ◽

Author(s):

Hans Renata ◽

Emily Shimizu ◽

Christian Zwick

Keyword(s):

Amino Acid ◽

Building Block ◽

Solid Phase ◽

Functional Characterization ◽

Free Standing ◽

Substrate Specificities ◽

Total Turnover

We report the functional characterization of two iron- and a-ketoglutarate-dependent dioxygenases that are capable of hydroxylating free-standing glutamine at its C3 and C4 position respectively. In particular, the C4 hydroxylase, Q4Ox, catalyzes the reaction with approximately 4,300 total turnover numbers, facilitating synthesis of a solid-phase compatible building block and stereochemical elucidation at the C4 position of the hydroxylated product. This work will enable the development of novel synthetic strategies to prepare useful glutamine derivatives and stimulate further discoveries of new amino acid hydroxylases with distinct substrate specificities.<br>

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Regiodivergent Biocatalytic Hydroxylation of L-Glutamine Facilitated by Characterization of Non-Heme Dioxygenases from Non-Ribosomal Peptide Biosyntheses

10.26434/chemrxiv.14206172 ◽

2021 ◽

Author(s):

Hans Renata ◽

Emily Shimizu ◽

Christian Zwick

Keyword(s):

Amino Acid ◽

Building Block ◽

Solid Phase ◽

Functional Characterization ◽

Free Standing ◽

Substrate Specificities ◽

Total Turnover

We report the functional characterization of two iron- and a-ketoglutarate-dependent dioxygenases that are capable of hydroxylating free-standing glutamine at its C3 and C4 position respectively. In particular, the C4 hydroxylase, Q4Ox, catalyzes the reaction with approximately 4,300 total turnover numbers, facilitating synthesis of a solid-phase compatible building block and stereochemical elucidation at the C4 position of the hydroxylated product. This work will enable the development of novel synthetic strategies to prepare useful glutamine derivatives and stimulate further discoveries of new amino acid hydroxylases with distinct substrate specificities.<br>

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Structural and mechanical properties of free-standing multiwalled carbon nanotube paper prepared by an aqueous mediated process

Journal of Materials Science ◽

10.1007/s10853-017-0983-z ◽

2017 ◽

Vol 52 (12) ◽

pp. 7503-7515 ◽

Cited By ~ 6

Author(s):

Sushant Sharma ◽

Bhanu Pratap Singh ◽

Arun Singh Babal ◽

Satish Teotia ◽

Jeevan Jyoti ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Nanotube ◽

Multiwalled Carbon Nanotube ◽

Free Standing ◽

Multiwalled Carbon

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UV Irradiated Graphene-Based Nanocomposites: Change in the Mechanical Properties by Local HarmoniX Atomic Force Microscopy Detection

Materials ◽

10.3390/ma12060962 ◽

2019 ◽

Vol 12 (6) ◽

pp. 962 ◽

Cited By ~ 2

Author(s):

Liberata Guadagno ◽

Carlo Naddeo ◽

Marialuigia Raimondo ◽

Vito Speranza ◽

Roberto Pantani ◽

...

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Mechanical Stability ◽

Uv Light ◽

Ultra Violet ◽

Graphene Nanoplatelets ◽

Free Standing ◽

Force Microscopy ◽

Atomic Force ◽

Acquisition Mode

Epoxy based coatings are susceptible to ultra violet (UV) damage and their durability can be significantly reduced in outdoor environments. This paper highlights a relevant property of graphene-based nanoparticles: Graphene Nanoplatelets (GNPs) incorporated in an epoxy-based free-standing film determine a strong decrease of the mechanical damages caused by UV irradiation. The effects of UV light on the morphology and mechanical properties of the solidified nanocharged epoxy films are investigated by Atomic Force Microscopy (AFM), in the acquisition mode “HarmoniX.” Nanometric-resolved maps of the mechanical properties of the multi-phase material evidence that the incorporation of low percentages, between 0.1% and 1.0% by weight, of graphene nanoplatelets (GNPs) in the polymeric film causes a relevant enhancement in the mechanical stability of the irradiated films. The beneficial effect progressively increases with increasing GNP percentage. The paper also highlights the potentiality of AFM microscopy, in the acquisition mode “HarmoniX” for studying multiphase polymeric systems.

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