scholarly journals Colloidal Lignin Particles as Adhesives for Soft Materials

2018 ◽  
Author(s):  
Maija-Liisa Mattinen ◽  
Guillaume Riviere ◽  
Alexander Henn ◽  
Robertus Wahyu N. Nugroho ◽  
Timo Leskinen ◽  
...  
Keyword(s):  
Soft Materials ◽  
Potential Method ◽  
Size Exclusion ◽  
Force Microscopy ◽  
Young’S Moduli ◽  
Atomic Force ◽  
Transmission Electron ◽  
Exclusion Chromatography ◽  
Beta Casein ◽  
Adhesive Formulation

Lignin has interesting functionalities to be exploited in adhesives for medicine, foods and textiles. Nanoparticles (NPs) <100 nm coated with poly(L-lysine), PL and poly(L-glutamic acid) PGA were prepared from the laccase treated lignin to coat nanocellulose fibrils (CNF) with heat. NPs ca. 300 nm were prepared, β-casein coated and cross-linked with transglutaminase (Tgase) to agglutinate chamois specimens. Size exclusion chromatography (SEC) and Fourier-transform infrared (FTIR) spectroscopy were used to characterize polymerized lignin, zetapotential and dynamic light scattering (DLS) to ensure coating of colloidal lignin particles (CLPs). Protein adsorption on lignin was studied by quartz crystal microbalance (QCM). Atomic force microscopy (AFM) was exploited to examine interactions between different polymers and to image NPs with transmission electron microscopy (TEM). Tensile testing showed, when using CLPs for the adhesion, the stress improved ca. 10 and strain ca. 6 times compared to polymeric lignin. For the β-casein NPs the values were 20 and 8, respectively, and for the β-casein coated CLPs between these two cases. When NPs were dispersed in adhesive formulation, the Young's moduli confirmed significant improvement in the elasticity of the joints over the adhesive alone. Exploitation lignin in nanoparticulate morphology is a potential method to prepare bionanomaterials for advanced applications.

scholarly journals Colloidal Lignin Particles as Adhesives for Soft Materials

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1001 ◽  
Author(s):  
Maija-Liisa Mattinen ◽  
Guillaume Riviere ◽  
Alexander Henn ◽  
Robertus Nugroho ◽  
Timo Leskinen ◽  
...  
Keyword(s):  
Quartz Crystal ◽  
Soft Materials ◽  
Potential Method ◽  
Size Exclusion ◽  
Force Microscopy ◽  
Young’S Moduli ◽  
Atomic Force ◽  
Transmission Electron ◽  
Exclusion Chromatography ◽  
Adhesive Formulation

Lignin has interesting functionalities to be exploited in adhesives for medicine, foods and textiles. Nanoparticles (NPs) < 100 nm coated with poly (L-lysine), PL and poly(L-glutamic acid) PGA were prepared from the laccase treated lignin to coat nanocellulose fibrils (CNF) with heat. NPs ca. 300 nm were prepared, β-casein coated and cross-linked with transglutaminase (Tgase) to agglutinate chamois. Size exclusion chromatography (SEC) and Fourier-transform infrared (FTIR) spectroscopy were used to characterize polymerized lignin, while zeta potential and dynamic light scattering (DLS) to ensure coating of colloidal lignin particles (CLPs). Protein adsorption on lignin was studied by quartz crystal microbalance (QCM). Atomic force microscopy (AFM) was exploited to examine interactions between different polymers and to image NPs with transmission electron microscopy (TEM). Tensile testing showed, when using CLPs for the adhesion, the stress improved ca. 10 and strain ca. 6 times compared to unmodified Kraft. For the β-casein NPs, the values were 20 and 8, respectively, and for the β-casein coated CLPs between these two cases. When NPs were dispersed in adhesive formulation, the increased Young’s moduli confirmed significant improvement in the stiffness of the joints over the adhesive alone. Exploitation of lignin in nanoparticulate morphology is a potential method to prepare bionanomaterials for advanced applications.

Chromatographic Separation of Single Wall Carbon Nanotubes

2006 ◽  
Vol 922 ◽  
Author(s):  
Barry J. Bauer ◽  
Vardhan Bajpai ◽  
Jeffrey A. Fagan ◽  
Matthew L. Becker ◽  
Erik K. Hobbie
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Modification ◽  
Size Exclusion ◽  
Covalent Attachment ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon ◽  
Force Microscopy ◽  
Atomic Force ◽  
Exclusion Chromatography ◽  
Chromatographic Detection

AbstractSize exclusion chromatography (SEC) has been used to separate single wall carbon nanotubes (SWNT) dispersed by chemical modification in organic solvents and by DNA in aqueous solution. The chromatographic detection includes size sensitive detectors, multi-angle light scattering (MALS) and intrinsic viscosity (IV), which can provide information on the size and shape of the SEC fractions. The dispersions were also characterized by small angle neutron scattering (SANS) and atomic force microscopy (AFM). Chemical modification was accomplished by covalent attachment of octadecyl amine to acid treated SWNT and by covalent attachment of butyl groups through free radical grafting. Both covalent attachment methods produced dispersions that contained impurities or clusters of SWNT. The DNA dispersions produced the best dispersions, being predominately single nanotubes.

Mucoadhesive interactions

2003 ◽  
Vol 31 (5) ◽  
pp. 1036-1041 ◽  
Author(s):  
S.E. Harding
Keyword(s):  
Analytical Ultracentrifugation ◽  
Physiological Solution ◽  
Size Exclusion ◽  
Molecular Processes ◽  
Adhesive Properties ◽  
Cationic Protein ◽  
Force Microscopy ◽  
Atomic Force ◽  
Imaging Probes ◽  
Exclusion Chromatography

The adhesive properties of certain types of biopolymer can be used to increase the residence time of orally or nasally administered drugs. A fuller understanding of the molecular processes underpinning such ‘mucoadhesive’ phenomena will help in the optimal design of delivery systems. The interactions involved are, however, less well defined compared with those often encountered in protein-recognition phenomena: mucoadhesive interaction products can be very large and polydisperse, so to probe them we need to adopt a different strategy to those used by protein biochemists. Reviewed herein is some of the recent work at physiological or near-physiological solution conditions involving molecular hydrodynamics – with analytical ultracentrifugation and SEC-MALLs (size-exclusion chromatography coupled to multi-angle laser light scattering) as the cornerstones – reinforced by viscometry and the imaging probes of electron microscopy and atomic force microscopy. These clearly demonstrate the mucoadhesive properties of both an unusual cationic protein [Deacon, Davis, Waite and Harding (1998) Biochemistry 37, 14108–14112] and more significantly chitosan polysaccharides of varying degrees of charge/acetylation as a function of solution conditions, and are providing the platform for the construction of stable formulations.

In situ Determination and Imaging of Physical Properties of Soft Organic Materials by Analytical Transmission Electron Microscopy

2014 ◽  
Vol 20 (3) ◽  
pp. 916-923 ◽  
Author(s):  
Nadejda B. Matsko ◽  
Franz P. Schmidt ◽  
Ilse Letofsky-Papst ◽  
Artem Rudenko ◽  
Vikas Mittal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Soft Materials ◽  
Analytical Transmission Electron Microscopy ◽  
Strong Correlations ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Phase Images ◽  
Material Contrast

AbstractAnalytical transmission electron microscopy (ATEM) offers great flexibility in identification of the structural—chemical organization of soft materials at the level of individual macromolecules. However, the determination of mechanical characteristics such as hardness/elasticity of the amorphous and polycrystalline organic substances by ATEM has been problematic so far. Here, we show that energy filtered TEM (EFTEM) measurements enable direct identification and study of mechanical properties in complex (bio-)polymer systems of relevance for different industrial and (bio-)medical applications. We experimentally demonstrate strong correlations between hardness/elasticity of different polymers (polycaprolactone, polylactid, polyethelene, etc.) and their volume plasmon energy. Thickness and anisotropy effects, which substantially mask the material contrast in EFTEM bulk plasmon images, can be adequately removed by normalizing the latter by carbon elemental map. EFTEM data has been validated using atomic force microscopy phase images, where phase shift related to the hardness and elastic modulus of the materials.

Effect of Ozonation on Assembly of Xylans

Holzforschung ◽  
2003 ◽  
Vol 57 (5) ◽  
pp. 496-502 ◽  
Author(s):  
Å. Linder ◽  
J. P. Roubroeks ◽  
P. Gatenholm
Keyword(s):  
Molecular Structure ◽  
Aqueous Solution ◽  
Molar Mass ◽  
Surface Structures ◽  
Size Exclusion ◽  
Aromatic Rings ◽  
Muconic Acid ◽  
Force Microscopy ◽  
Atomic Force ◽  
Exclusion Chromatography

Summary In this study the molecular structure of birch xylan was altered by ozonation. Longer ozonation times increased the cleavage of aromatic rings in the lignin residues attached to the xylan molecules, resulting in the formation of muconic acid derivatives and other carboxylic acid structures. Size exclusion chromatography showed a decreasing molar mass of xylan after ozonation. The ozonation improved xylan solubility as evidenced by the reduced amounts of aggregates in aqueous solution. Atomic force microscopy showed increases in the sizes of the aggregates. Furthermore, the ozonation resulted in a decreased ability of xylan to assemble into particle-like structures on cellulose surfaces. We therefore believe that there is a relationship between xylan aggregation in aqueous solution and the formation of xylan surface structures on cellulose.

Scanning tunneling microscopy and atomic force microscopy: New tools for biology

1989 ◽  
Vol 47 ◽  
pp. 778-779
Author(s):  
CE Bracker ◽  
P. K. Hansma
Keyword(s):  
Physical Property ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Small Scale ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
New Family ◽  
Small Probe ◽  
Atomic Force ◽  
Transmission Electron

A new family of scanning probe microscopes has emerged that is opening new horizons for investigating the fine structure of matter. The earliest and best known of these instruments is the scanning tunneling microscope (STM). First published in 1982, the STM earned the 1986 Nobel Prize in Physics for two of its inventors, G. Binnig and H. Rohrer. They shared the prize with E. Ruska for his work that had led to the development of the transmission electron microscope half a century earlier. It seems appropriate that the award embodied this particular blend of the old and the new because it demonstrated to the world a long overdue respect for the enormous contributions electron microscopy has made to the understanding of matter, and at the same time it signalled the dawn of a new age in microscopy. What we are seeing is a revolution in microscopy and a redefinition of the concept of a microscope.Several kinds of scanning probe microscopes now exist, and the number is increasing. What they share in common is a small probe that is scanned over the surface of a specimen and measures a physical property on a very small scale, at or near the surface. Scanning probes can measure temperature, magnetic fields, tunneling currents, voltage, force, and ion currents, among others.

The Electrical Characterization and Physical Failure Analysis for Transistor Gate Leakage

2006 ◽  
Author(s):  
Tsung-Te Li ◽  
Chao-Chi Wu ◽  
Jung-Hsiang Chuang ◽  
Jon C. Lee
Keyword(s):  
Failure Analysis ◽  
Electrical Characterization ◽  
Physical Analysis ◽  
Gate Leakage ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Voltage Stress ◽  
Leakage Site

Abstract This article describes the electrical and physical analysis of gate leakage in nanometer transistors using conducting atomic force microscopy (C-AFM), nano-probing, transmission electron microscopy (TEM), and chemical decoration on simulated overstressed devices. A failure analysis case study involving a soft single bit failure is detailed. Following the nano-probing analysis, TEM cross sectioning of this failing device was performed. A voltage bias was applied to exaggerate the gate leakage site. Following this deliberate voltage overstress, a solution of boiling 10%wt KOH was used to etch decorate the gate leakage site followed by SEM inspection. Different transistor leakage behaviors can be identified with nano-probing measurements and then compared with simulation data for increased confidence in the failure analysis result. Nano-probing can be used to apply voltage stress on a transistor or a leakage path to worsen the weak point and then observe the leakage site easier.

scholarly journals A Bacterially-Expressed Recombinant Envelope Protein from Usutu Virus Induces Neutralizing Antibodies in Rabbits

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 157
Author(s):  
Kinga Böszörményi ◽  
Janet Hirsch ◽  
Gwendoline Kiemenyi Kayere ◽  
Zahra Fagrouch ◽  
Nicole Heijmans ◽  
...  
Keyword(s):  
Envelope Protein ◽  
Neutralizing Antibodies ◽  
Size Exclusion ◽  
Vitro Assay ◽  
Usutu Virus ◽  
Transmission Electron ◽  
Exclusion Chromatography ◽  
Efficacious Vaccine ◽  
Human Infections

Background: Recently, an emerging flavivirus, Usutu virus (USUV), has caused an epidemic among birds in Europe, resulting in a massive die-off in Eurasian blackbirds. Currently found only in Europe and Africa, it can be envisioned that Usutu virus will follow the path of other flaviviruses, like West Nile virus and Zika virus, and will spread via its mosquito vectors and bird hosts to other parts of the world. Several cases of human infections by Usutu virus have already been published. Anticipating this spread, development of an efficacious vaccine would be highly desirable. Method: This study describes the production in E. coli, purification, and refolding of a partial USUV envelope protein. Prior to immunization, the protein was characterized using size exclusion chromatography, transmission electron microscopy and dynamic light scattering, showing the limited presence of virus-like structures, indicating that the protein solution is probably a mixture of mono and multimeric envelope proteins. Results: Immunizations of two rabbits with the refolded E-protein fraction, mixed with a strong adjuvant, resulted in the generation of neutralizing antibodies, as evidenced in an in vitro assay. Discussion: The way forward towards a subunit vaccine against Usutu virus infection is discussed.

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