scholarly journals VELCRO-INSPIRED SUPRAMOLECULAR SYSTEM FOR SILICA–RUBBER COUPLING

2020 ◽  
Vol 93 (4) ◽  
pp. 672-682
Author(s):  
Rafal Anyszka ◽  
Karolina Beton ◽  
Maja Szczechowicz ◽  
Dariusz M. Bielinski ◽  
Anke Blume
Keyword(s):  
Silica Surface ◽  
Rubber Matrix ◽  
Supramolecular System ◽  
New Approach ◽  
Silica Surfaces ◽  
Covering System ◽  
Coupling System ◽  
Chemical Coupling ◽  
Common Coupling ◽  
Reference Samples

ABSTRACT The state-of-the-art silica–rubber coupling is based on forming chemical links between a silica surface and rubber macromolecules. However, the chemical links are relatively short and stiff, thus in case of a chemical breakage they are highly unlikely to recombine. This could result in a potential deterioration of the interphase properties over time. To overcome this drawback, a new approach to silica–rubber coupling was investigated in the current study. The new approach is inspired by the Velcro hook-and-loop system from nature that facilitates a re-connectability, thus re-formation of the interphase properties in case of a breakage. For this, various long oligomeric brushes were grafted onto silica surfaces considered to act as supramolecular hooks. Such modified silica were dispersed in rubber and vulcanized. The resulting cross-linked rubber matrix is considered to act as supramolecular loops. The prepared vulcanizates were compared with reference samples containing common coupling or covering agents. The reinforcing potential provided by the newly developed system is lower than the chemical coupling system but considerably higher than the covering system. The new system also provides better mechanical properties, recovery after cycling stretching, and heat treatment than the references. A new reinforcing mechanism is proposed for the silica grafted with oligomeric brushes that exhibits a good chemical compatibility to the rubber matrix.

Determination of the Orientation of Silanes on Silica Surfaces by Fourier Transform Infrared Photoacoustic Spectroscopy

1986 ◽  
Vol 40 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Marek W. Urban ◽  
Jack L. Koenig
Keyword(s):  
Fourier Transform ◽  
Photoacoustic Spectroscopy ◽  
Surface Coverage ◽  
Silica Surface ◽  
Fourier Transform Infrared ◽  
Coupling Agents ◽  
Surface Hydroxyl ◽  
Silica Surfaces ◽  
Quantitative Surface Analysis ◽  
Infrared Photoacoustic Spectroscopy

Fourier transform infrared photoacoustic spectroscopy has been used for quantitative surface analysis of silica treated with trifunctional coupling agents such as γ-Methacryloxypropyltriethoxysilane (γ-MPS), γ-Glycidoxypropyltrimethoxysilane (γ-GPS), and γ-Aminopropyltri-ethoxysilane (γ-APS). The calibration curves are obtained for several characteristic bands of the coupling agents. Using a highly polarizable gas in the photoacoustic cell and comparing the spectra with a nonpolarizable coupling gas, it is possible to evaluate orientation of the coupling agents on the silica surface. The type of orientation is a function of the extent of surface coverage. At low surface coverage, coupling agents tend to take a perpendicular orientation with respect to the surface, and increasing surface coverage leads to parallel orientation. Increasing the coupling agent concentration also causes orientational changes of the species which form chemical bonds with the silica surface (hydroxyl, water, and carbonyl groups).

scholarly journals Clean chlorination of silica surfaces by a single-site substitution approach

2018 ◽  
Vol 47 (12) ◽  
pp. 4301-4306 ◽  
Author(s):  
Niladri Maity ◽  
Samir Barman ◽  
Edy Abou-Hamad ◽  
Valerio D'Elia ◽  
Jean-Marie Basset
Keyword(s):  
Silica Surface ◽  
Single Site ◽  
Silanol Groups ◽  
Silica Surfaces ◽  
Selective Chlorination ◽  
Hydrogen Bonded

Unveiling a clean, selective chlorination method for the quantitative substitution of well-defined non-hydrogen bonded silanol groups of the silica surface.

A method for introducing organic functional groups on silica surfaces using a functionalized vinylsilane containing polymer

2015 ◽  
Vol 6 (4) ◽  
pp. 555-560 ◽  
Author(s):  
Jung-Woo Park ◽  
Dong-Su Kim ◽  
Min-Seok Kim ◽  
Ji-Hwan Choi ◽  
Chul-Ho Jun
Keyword(s):  
Functional Groups ◽  
Silica Surface ◽  
New Method ◽  
Silica Surfaces ◽  
Organic Functional Groups

A new method for introducing robustly bound organic functional groups on the silica surface using a vinylsilane-containing polymer is developed.

Models for biomedical interfaces: a computational study of quinone-functionalized amorphous silica surface features

2017 ◽  
Vol 19 (11) ◽  
pp. 7793-7806 ◽  
Author(s):  
Marta Corno ◽  
Massimo Delle Piane ◽  
Patrick Choquet ◽  
Piero Ugliengo
Keyword(s):  
Amorphous Silica ◽  
Silica Surface ◽  
Computational Study ◽  
Antimicrobial Properties ◽  
Surface Features ◽  
Silica Surfaces

The structural and IR features of amorphous silica surfaces, functionalized by ortho-benzoquinone groups, were computed to obtain a deeper knowledge of multifunctional coatings with antimicrobial properties.

Silica Surface Modification Reactions with Aluminum and Boron Alkyls and (Alkyl)Chlorides: Reactivities and Surface Nanostructures

2008 ◽  
Vol 8 (2) ◽  
pp. 660-666 ◽  
Author(s):  
Jonathan P. Blitz ◽  
Jeannine M. Christensen ◽  
Carol A. Deakyne ◽  
Vladimir M. Gun'ko
Keyword(s):  
Chemical Structure ◽  
Silica Surface ◽  
Molecular Level ◽  
Ring Structure ◽  
Membered Ring ◽  
Silica Surfaces ◽  
Surface Nanostructures ◽  
Reactive Groups ◽  
Aluminum Compounds ◽  
Silica Surface Modification

The functionalization of nanoporous and nanoparticulate silica surfaces requires a molecular level understanding of the chemistry and structures which result from surface reactions. Various types of reactive groups on silica can participate, giving rise to different nanostructures. It is necessary to devise methods to alter the reactive nature of silica surfaces to control the nanoscale chemical structure. Various silica pretreatments are utilized to alter the silica surface prior to reaction with AlEt3, AlEtxCl3−x, BEt3, BCl3, and TiCl4. Reactivities of these surface reactive reagents are compared. Aluminum compounds preferentially react with loss of alkane rather than HCl, in a thermodynamically controlled reaction as determined by ab initio computational methods. Consideration of the structures resulting from reaction of the boron and aluminum compounds above with silica surface diols has been taken into account. Particular attention has been paid to the possibility of forming a cyclic 4-membered ring structure. While this is unlikely to form from reactions with MCl3, such structures may be possible when reacting silicas with MMe3.

FUNCTIONALIZED SILICA AS AN ECO-FRIENDLY VULCANIZATION ACCELERATOR TO ENHANCE THE INTERFACIAL INTERACTION IN NR/SILICA COMPOSITES

2020 ◽  
pp. 000-000
Author(s):  
Kaizheng Zhu ◽  
Yang Pan ◽  
Jie Wu ◽  
Kuncai Li ◽  
Xiwei Guo ◽  
...  
Keyword(s):  
Silica Surface ◽  
Decomposition Temperature ◽  
Interfacial Interaction ◽  
Rubber Matrix ◽  
Functionalized Silica ◽  
Rubber Industry ◽  
Degradation Temperature ◽  
Technological Opportunities ◽  
Vulcanization Accelerator

ABSTRACT Xanthate is a class of non-toxic, rapid, and eco-friendly rubber vulcanization accelerator, but it is seldom used in the rubber industry because of its poor thermostability and ease of decomposition. To overcome these drawbacks, silica supported sodium isobutyl xanthate (silica-s-SIBX) was prepared by chemically bonding SIBX onto the silica surface. After loading, the initial degradation temperature (T0), maximum degradation temperature (Tp), and final decomposition temperature (Tf) of silica-s-SIBX were increased by 85.8, 118.9, and 146.9 °C, respectively. Meanwhile, silica-s-SIBX could not only improve the dispersion of fillers in the rubber but also enhance the interfacial interaction between silica and the rubber matrix. Therefore, it may offer new scientific and technological opportunities for preparation of green additives in the rubber industry.

Filler-Elastomer Interactions. Part I: Silica Surface Energies and Interactions with Model Compounds

1991 ◽  
Vol 64 (4) ◽  
pp. 559-576 ◽  
Author(s):  
Meng-Jiao Wang ◽  
Siegfried Wolff ◽  
Jean-Baptiste Donnet
Keyword(s):  
Functional Groups ◽  
Phenyl Ring ◽  
Silica Surface ◽  
Rubber Matrix ◽  
Low Molecular Weight ◽  
Free Energies ◽  
Model Compounds ◽  
Surface Energies ◽  
Surface Areas ◽  
Degree Of Unsaturation

Abstract Inverse gas-solid chromatography, operated at infinite dilution, has been used to assess the surface energies of silicas, both fumed and precipitated. The dispersive components of the surface free energies of the silicas were calculated from the free energies of adsorption, corresponding to the —CH2— group, obtained from n-alkane adsorption. The specific components of the surface energies were evaluated separately by comparison of the free energies of adsorption of polar probes with those of n-alkanes, based on the surface areas covered by the probe molecules. The results indicate that while the dispersive components of silica surface energies is somewhat higher for the fumed silicas, the specific components are much higher for precipitated silicas, probably resulting from the higher silanol concentration on their surfaces. Moreover, the interaction able to take place between rubber matrix and the silicas are also estimated chromatographically from the adsorptions of low-molecular-weight analogs of elastomers. The free energies and enthalpies indicate that the interactions of functional groups with the fillers decrease in the order of nitrile, phenyl ring, double bond. The saturated rubber analogs show lower interactions with silicas. The lowest interactions of iso-alkanes imply poor interactions between butyl rubber and the fillers. As expected, the experimental data reflect an attenuation of polymer-silica interactions with decreasing content of functional groups and degree of unsaturation in NR, BR, SBR, and NBR.

Surface Forces and Adhesion Between Dissimilar Materials Measured in Various Environments

1989 ◽  
Vol 170 ◽  
Author(s):  
Douglas T. Smith ◽  
Roger G. Horn
Keyword(s):  
Aqueous Solution ◽  
Silica Surface ◽  
Dissimilar Materials ◽  
Surface Force ◽  
Surface Forces ◽  
Mica Surface ◽  
Surface Force Apparatus ◽  
Preliminary Results ◽  
Silica Surfaces ◽  
The Past

AbstractThe Israelachvili surface force apparatus has been used extensively over the past decade to make detailed measurements of surface forces and adhesion between very smooth solids in various liquid and vapor environments. Most of those measurements have been made with mica surfaces, but we have recently developed a method of preparing smooth silica surfaces for use in place of the mica. The silica surfaces adhere in dry and humid atmospheres, but do not adhere when immersed in water.The use of a second material not only broadens the scope of the Israelachvili technique, but also enables studies of forces and adhesion between dissimilar materials. In this work, we present the results of measurements of adhesion in air and forces in aqueous solution between two silica surfaces; we also report preliminary results of the adhesion between a mica surface and a silica surface.

scholarly journals Realization of depth reference samples with surfaces amplitudes between 0.1 nm and 5 nm

2019 ◽  
Vol 215 ◽  
pp. 03004
Author(s):  
Annemarie Finzel ◽  
Gregor Dornberg ◽  
Stephan Görsch ◽  
Martin Mitzschke ◽  
Jens Bauer ◽  
...  
Keyword(s):  
Ion Beam ◽  
Surface Profile ◽  
Ion Beam Etching ◽  
New Approach ◽  
Surface Profiles ◽  
Transparent Materials ◽  
Sinusoidal Surface ◽  
Reference Samples ◽  
Reactive Ion Beam Etching

A new approach for the realization of depth reference samples is presented. By a combination of photolithography, reactive ion beam etching, surface planarization with photoresists and a subsequent coating with non-transparent materials, defined sinusoidal surface profiles are generated which can be used as depth references for the comparison and calibration of different surface profile measurements. The smallest realized surface amplitudes are in the range of less than 0.1 nm.

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