scholarly journals Retracted Article: Spatially resolved mechanical properties of photo-responsive azobenzene-based supramolecular gels

RSC Advances ◽  
2017 ◽  
Vol 7 (43) ◽  
pp. 26827-26833 ◽  
Author(s):  
Gyuri Mun ◽  
Heekyoung Choi ◽  
Nayoung Im ◽  
Junho Ahn ◽  
Jaehyeon Park ◽  
...  

The mechanical properties of azobenzene-based gelators were finely controlled by UV irradiation.

RSC Advances ◽  
2017 ◽  
Vol 7 (84) ◽  
pp. 53056-53056
Author(s):  
Gyuri Mun ◽  
Heekyoung Choi ◽  
Nayoung Im ◽  
Junho Ahn ◽  
Jaehyeon Park ◽  
...  

Retraction of ‘Spatially resolved mechanical properties of photo-responsive azobenzene-based supramolecular gels’ by Gyuri Mun et al., RSC Adv., 2017, 7, 26827–26833.


2018 ◽  
Vol 89 (9) ◽  
pp. 1807-1822
Author(s):  
Yunjie Yin ◽  
Yanyan Zhang ◽  
Xiaoqian Ji ◽  
Tao Zhao ◽  
Chaoxia Wang

A novel strategy was reported on the design and fabrication of functional photosensitive hybrid sols (FPHSs) by non-alcoholic emulsification in the presence of a TiO2 nanoparticle and photoinitiator via a sol-gel process using tetraethylorthosilicate, γ-methacryloxypropyltrimethoxysilane (MPS) and hydrophobic silane coupling agents as precursors. Smart cellulose substrates with alterable superhydrophobic–superhydrophilic conversion were fabricated using FPHS via the ultraviolet (UV) curing process. The liquid FPHS was photocured into solid gel during UV irradiation for 40 s with MPSs in FPHS, which was verified via Fourier transform infrared spectra. The cellulose substrates were modified with FPHSs, and the water contact angles of the modified cellulose substrates were more than 150°. The superhydrophobicity was improved by the gathering of hydrophobic chains and particle deposition of hybrid gel on the fiber surface. Nevertheless, the water contact angles of the modified cellulose substrates were receded with UV irradiation from 158° to 0° in 200 min, due to TiO2 photoinduction. The irradiated cellulose substrates were placed in the dark, and the water contact angles were recovered to about 130°, gradually. What is more, the reversible process can be repeated more than eight times. The modified cellulose substrate presented excellent washing fastness, even suffering 10 times washing processing. The mechanical properties, including breaking strength and elongation rate, were improved after the coating and UV curing process, which considerably remedied the defects of the heating curing process on the mechanical properties.


1977 ◽  
Vol 47 (6) ◽  
pp. 423-428 ◽  
Author(s):  
A. Garton ◽  
D. J. Carlsson ◽  
P. Z. Sturgeon ◽  
D. M. Wiles

The elongation-at-break of highly-oriented polypropylene monofilaments is much less affected by photo-oxidation build-up than undrawn or partially-oriented filaments. This appears to result from the very poor lateral cohesion of the fibril bundles in the highly-oriented filament, limiting restructuring and cracking to a thin surface layer. For less-oriented samples photo-oxidation-induced restructuring of the surface layer results in deep cracks that can propagate under stress, greatly embrittling the sample. Areas of filaments cold drawn by, for example, bending or stretching deteriorate very rapidly on uv irradiation as a result of strain-induced chromophore formation, and fracture occurs first at these points. Oxidation-product levels (either hydroperoxide or carbonyl) are shown to be an unreliable index of the extent of deterioration of mechanical properties resulting from uv exposure.


Scanning ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Emil Sandoz-Rosado ◽  
Michael R. Roenbeck ◽  
Kenneth E. Strawhecker

High-performance materials like ballistic fibers have remarkable mechanical properties owing to specific patterns of organization ranging from the molecular scale, to the micro scale and macro scale. Understanding these strategies for material organization is critical to improving the mechanical properties of these high-performance materials. In this work, atomic force microscopy (AFM) was used to detect changes in material composition at an extremely high resolution with transverse-stiffness scanning. New methods for direct quantification of material morphology were developed, and applied as an example to these AFM scans, although these methods can be applied to any spatially-resolved scans. These techniques were used to delineate between subtle morphological differences in commercial ultra-high-molecular-weight polyethylene (UHMWPE) fibers that have different processing conditions and mechanical properties as well as quantify morphology in commercial Kevlar®, a high-performance material with an entirely different organization strategy. Both frequency analysis and visual processing methods were used to systematically quantify the microstructure of the fiber samples in this study. These techniques are the first step in establishing structure-property relationships that can be used to inform synthesis and processing techniques to achieve desired morphologies, and thus superior mechanical performance.


Nanoscale ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 3275-3280 ◽  
Author(s):  
Ana M. Fuentes-Caparrós ◽  
Francisco de Paula Gómez-Franco ◽  
Bart Dietrich ◽  
Claire Wilson ◽  
Christopher Brasnett ◽  
...  

Annealing in a two-component supramolecular gel leads to a self-sorted network, which has significantly different mechanical properties to the as-prepared gels.


2004 ◽  
Vol 15 (11) ◽  
pp. 662-668 ◽  
Author(s):  
Wonseop Jin ◽  
M. Abdul Kader ◽  
Weon-Bae Ko ◽  
Changwoon Nah

IAWA Journal ◽  
1997 ◽  
Vol 18 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Rupert Wimmer ◽  
Barry N. Lucas

Mechanical characterizations of the S2 layers and the cell corner middle lamella in the axial direction were investigated in spruce wood, A mechanical properties microprobe capable of measuring hardness and Young's modulus on a spatially resolved basis similar to that of an electron beam microprobe was used. Hardness of the cell comer middle lamella was found to be almost as high as that of the secondary wall, but the Young's modulus of the cell corner middle lamella was 50% less than that of the S2' The S2 showed constant hardness over its range of Young's modulus, but the cell corner middle lamella exhibited a strong correlation (R2 = 0.55) between hardness and the Young's modulus. Further investigations are needed to directly combine chemical and micromechanical properties and also to investigate the mechanical effects of the high variability of cell corner middle lamella chemistry.


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