scholarly journals Characterization of Porous Structures of Cellulose Nanofibrils Loaded with Salicylic Acid

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2538
Author(s):  
Birgitte Hjelmeland McDonagh ◽  
Gary Chinga-Carrasco
Keyword(s):  
Salicylic Acid ◽  
Cellulose Nanofibrils ◽  
Small Scale ◽  
Porous Structures ◽  
Pulp Fibers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Agricultural Applications ◽  
Plasma Mass Spectrometry ◽  
Unbleached Pulp

Bleached and unbleached pulp fibers were treated with 2,2,6,6-tetramethylpyperidine-1-oxyl (TEMPO) mediated oxidation to obtain cellulose nanofibrils (CNFs). The resulting bleached and unbleached CNFs were mixed with salicylic acid (0, 5, 10, 20 wt%) before casting and freeze-drying or 3D-printing. A series of methods were tested and implemented to characterize the CNF materials and the porous structures loaded with salicylic acid. The CNFs were characterized with atomic force microscopy and laser profilometry, and release of salicylic acid was quantified with UV-visible absorbance spectroscopy, conductivity measurements, and inductive coupled plasma mass spectrometry (ICP-MS). Fourier-transform infrared spectroscopy (FTIR) complemented the analyses. Herein, we show that aerogels of bleached CNFs yield a greater release of salicylic acid, compared to CNF obtained from unbleached pulp. The results suggest that biodegradable constructs of CNFs can be loaded with a plant hormone that is released slowly over time, which may find uses in small scale agricultural applications and for the private home market.

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.

Preparation of Cellulose Nanofibrils by High-Pressure Homogenizer and Zein Composite Films

2013 ◽  
Vol 829 ◽  
pp. 534-538 ◽  
Author(s):  
Alireza Shakeri ◽  
Sattar Radmanesh
Keyword(s):  
Atomic Force Microscopy ◽  
High Pressure ◽  
Food Packaging ◽  
Cellulose Nanofibrils ◽  
Composite Films ◽  
Average Diameter ◽  
Nanocomposite Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
High Pressure Homogenizer

Cellulose nanofibrils ( NF ) have several advantages such as biodegradability and safety toward human health. Zein is a biodegradable polymer with potential use in food packaging applications. It appears that polymer nanocomposites are one of the most promising applications of zein films. Cellulose NF were prepared from starting material Microcrystalline cellulose (MCC) by an application of a high-pressure homogenizer at 20,000 psi and treatment consisting of 15 passes. Methods such as atomic force microscopy were used for confirmation of nanoscale size production of cellulose. The average diameter 45 nm were observed. Zeincellulose NF nanocomposite films were prepared by casting ethanol suspensions of Zein with different amounts of cellulose NF in the 0% to 5%wt. The nanocomposites were characterized by using Fourier transform infrared spectroscopy ( FTIR ), Atomic force microscopy ( AFM ) and X-ray diffraction ( XRD ) analysis. From the FTIR spectra the various groups present in the Zein blend were monitored. The homogeneity, morphology and crystallinity of the blends were ascertained from the AFM and XRD data, respectively. The thermal resistant of the zein nanocomposite films improved as the nanocellulose content increased. These obtained materials are transparent, flexible and present significantly better physical properties than the corresponding unfilled Zein films.

scholarly journals Cellulose-Cyclodextrin Co-Polymer for the Removal of Cyanotoxins on Water Sources

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2075
Author(s):  
Diego Gomez-Maldonado ◽  
Iris Beatriz Vega Erramuspe ◽  
Ilari Filpponen ◽  
Leena-Sisko Johansson ◽  
Salvatore Lombardo ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Cellulose Nanofibrils ◽  
Human Consumption ◽  
Nutrient Runoff ◽  
Force Microscopy ◽  
Atomic Force ◽  
Safe Limits ◽  
Ft Ir ◽  
Recreational Use

With increasing global water temperatures and nutrient runoff in recent decades, the blooming season of algae lasts longer, resulting in toxin concentrations that exceed safe limits for human consumption and for recreational use. From the different toxins, microcystin-LR has been reported as the main cyanotoxin related to liver cancer, and consequently its abundance in water is constantly monitored. In this work, we report a methodology for decorating cellulose nanofibrils with β-cyclodextrin or with poly(β-cyclodextrin) which were tested for the recovery of microcystin from synthetic water. The adsorption was followed by Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), allowing for real-time monitoring of the adsorption behavior. A maximum recovery of 196 mg/g was obtained with the modified by cyclodextrin. Characterization of the modified substrate was confirmed with Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analysis (TGA), and Atomic Force Microscopy (AFM).

Interaction of salicylic acid with zirconium diphosphate and its reactivity toward uranium (VI)

2018 ◽  
Vol 106 (4) ◽  
pp. 291-300
Author(s):  
Nidia García-González ◽  
Eduardo Ordoñez-Regil ◽  
María Guadalupe Almazán-Torres ◽  
Eric Simoni
Keyword(s):  
Salicylic Acid ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Analytical Techniques ◽  
Batch Method ◽  
Sorption Data ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Modified

AbstractThe interaction of salicylic acid with zirconium diphosphate surface and its reactivity toward uranium (VI) was investigated. The interaction of salicylic acid with zirconium diphosphate was firstly studied using several analytical techniques including atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The sorption of uranium (VI) onto surface-modified zirconium diphosphate was evaluated by the classical batch method at room temperature. This study showed that the uranium (VI) sorption onto zirconium diphosphate is influenced by the presence of salicylic acid. A fluorescence spectroscopy study revealed the presence of a uranyl specie onto the modified solid surface. The spectroscopy results were then used to restrain the modeling of experimental sorption data, which are interpreted in terms of a constant capacitance model using the FITEQL code. The results indicated that interaction between the uranium (VI) and the surface of zirconium diphosphate modified with salicylic acid leads to the formation of a ternary surface complex.

scholarly journals PROBING ATOMIC LEVEL INTERACTIONS IN NI NANORODS AND AFM CANTILEVER USING ATOMIC FORCE MICROSCOPY BASED F–D SPECTROSCOPY

2017 ◽  
Author(s):  
Sudipta Dutta ◽  
Mahesh Kumar Singh ◽  
M. S. Bobji
Keyword(s):  
Atomic Force Microscopy ◽  
Magnetic Interaction ◽  
Interaction Force ◽  
Small Scale ◽  
Magnetic Composite ◽  
Force Microscopy ◽  
Atomic Force ◽  
Lift Height ◽  
Afm Cantilever ◽  
Force Displacement

Atomic force microscopy based force-displacement spectroscopy is used to quantify magnetic interaction force between sample and magnetic cantilever. AFM based F–D spectroscopy is used widely to understand various surface-surface interaction at small scale. Here we have studied the interaction between a magnetic nanocomposite and AFM cantilevers. Two different AFM cantilever with same stiffness but with and without magnetic coating is used to obtain F–D spectra in AFM. The composite used has magnetic Ni nanophase distributed uniformly in an Alumina matrix. Retrace curves obtained using both the cantilevers on magnetic composite and sapphire substrate are compared. It is found for magnetic sample cantilever comes out of contact after traveling 100 nm distance from the actual point of contact. We have also used MFM imaging at various lift height and found that beyond 100nm lift height magnetic contrast is lost for our composite sample, which further confirms our F–D observation.

Fundamental frequencies of a nano beam used for atomic force microscopy (AFM) in tapping mode

MRS Advances ◽  
2018 ◽  
Vol 3 (42-43) ◽  
pp. 2617-2626 ◽  
Author(s):  
MALESELA K. MOUTLANA ◽  
SARP ADALI
Keyword(s):  
Atomic Force Microscopy ◽  
Degree Of Freedom ◽  
Small Scale ◽  
Single Degree Of Freedom ◽  
Tapping Mode ◽  
Force Microscopy ◽  
Single Degree ◽  
Nano Scale ◽  
Atomic Force ◽  
Tip Mass

ABSTRACTIn this study we investigate the motion of a torsionally restrained beam used in tapping mode atomic force microscopy (TM-AFM), with the aim of manufacturing at nano-scale. TM-AFM oscillates at high frequency in order to remove material or shape nano structures. Euler-Bernoulli theory and Eringen’s theory of non-local continuum are used to model the nano machining structure composed of two single degree of freedom systems. Eringen’s theory is effective at nano-scale and takes into account small-scale effects. This theory has been shown to yield reliable results when compared to modelling using molecular dynamics.The system is modelled as a beam with a torsional boundary condition at one end; and at the free end is a transverse linear spring attached to the tip. The other end of the spring is attached to a mass, resulting in a single degree of freedom spring-mass system. The motion of the tip of the beam and tip mass can be investigated to observe the tip frequency response, displacement and contact force. The beam and spring–mass frequencies contain information about the maximum displacement amplitude and therefore the sample penetration depth and this allows

scholarly journals Partitioning and Surficial Segregation of Trace Elements in Iron Oxides in Hydrothermal Fluid Systems

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 57
Author(s):  
Nikolay Smagunov ◽  
Vladimir Tauson ◽  
Sergey Lipko ◽  
Dmitriy Babkin ◽  
Taisa Pastushkova ◽  
...  
Keyword(s):  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Absorption Spectrometry ◽  
X Ray ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Atomic Force ◽  
Fluid Systems ◽  
Nonautonomous Phase ◽  
Plasma Mass Spectrometry

Partitioning experiments were done by hydrothermal synthesis of crystals containing trace elements (TEs) by internal sampling of fluid at the temperature of 450 °C and pressure of 1 kbar. The crystal phases obtained were magnetite, hematite, and Ni-spinel, which were studied using X-ray diffraction (XRD), X-ray electron probe microanalysis (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), atomic absorption spectrometry (AAS), and atomic force microscopy (AFM). The solutions from the sampler’s fluid probes were analysed by AAS for TEs included elements of the iron group plus aluminium. The highest co-crystallisation coefficients of TE and Fe between mineral and fluid (DTE/Fe) in magnetite were measured for V, Al, Ni and Cr (in decreasing order of n units in value), a lower value was observed for Co (2 × 10−1), and still lower values for Ti, Zn, and Mn (n × 10−2–10−3). In hematite, DTE/Fe values were highest for Al and V (order of n units in value), while lower values characterised Ti, Cr, and Co (n × 10−1–10−3), and the lowest values were exhibited by Cu, Mn, and Zn (n × 10−5). Copper was confirmed to be the most incompatible with all minerals studied; however, Cu had a high content on crystal surfaces. This surficial segregation contributes to the average TE concentration even when a thin layer of nonautonomous phase (NAP) is enriched in the element of interest. The accumulation of TEs on the surface of crystals increased bulk content 1–2 orders of magnitude above the content of structurally-bound elements even in coarse crystals. The inverse problem—evaluation of TE/Fe ratios in fluids involved in the formation of magnetite-containing deposits—revealed that the most abundant metals in fluids were Fe followed by Mn, Zn, and Cu, which comprised 10 to 30% of the total iron content.

scholarly journals Transverse viscoelastic properties of pulp fibers investigated with an atomic force microscopy method

2019 ◽  
Vol 54 (17) ◽  
pp. 11448-11461 ◽  
Author(s):  
Caterina Czibula ◽  
Christian Ganser ◽  
Tristan Seidlhofer ◽  
Christian Teichert ◽  
Ulrich Hirn
Keyword(s):  
Atomic Force Microscopy ◽  
Viscoelastic Properties ◽  
Pulp Fibers ◽  
Force Microscopy ◽  
Atomic Force Microscopy Method ◽  
Atomic Force ◽  
Microscopy Method

Analysis of precipitated lignin on kraft pulp fibers using atomic force microscopy

Cellulose ◽  
2012 ◽  
Vol 19 (3) ◽  
pp. 1013-1021 ◽  
Author(s):  
Franz J. Schmied ◽  
Christian Teichert ◽  
Lisbeth Kappel ◽  
Ulrich Hirn ◽  
Robert Schennach
Keyword(s):  
Atomic Force Microscopy ◽  
Kraft Pulp ◽  
Pulp Fibers ◽  
Force Microscopy ◽  
Atomic Force

An Atomic Force Microscopy Indentation Study of Biomaterial Properties

2005 ◽  
Author(s):  
E. J. Berger ◽  
S. Tripathy ◽  
K. Vemaganti ◽  
Y. M. Kolambkar ◽  
H. X. You ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Soft Materials ◽  
Data Interpretation ◽  
Close Relative ◽  
Small Scale ◽  
Force Microscopy ◽  
Afm Indentation ◽  
Atomic Force ◽  
Biomechanical Investigation ◽  
Series Type

Atomic force microscopy (AFM) is a powerful and increasingly common modality of biomechanical investigation, including imaging, force spectroscopy, and microrheology. AFM indentation of biomaterials requires use of a contact model for data interpretation and material property extraction, and a large segment of the scientific community uses the Hertz model or a close relative for small-scale indentation of thin, soft materials in high strain applications. We present experimental results and analytical/numerical modeling which lead to two main conclusions: (i) Hertzian mechanics are useful in a surprisingly large parameter range, including scenarios in which the underlying assumptions are seemingly violated, and (ii) the Hertz solution serves as a useful base from which power-series type solutions can be derived for a variety of non-Hertzian effects.

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