scholarly journals Infrared photo-induced force microscopy unveils nanoscale features of Norway spruce fibre wall

Cellulose ◽  
2021 ◽  
Author(s):  
Kavindra Kumar Kesari ◽  
Padraic O’Reilly ◽  
Jani Seitsonen ◽  
Janne Ruokolainen ◽  
Tapani Vuorinen
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Norway Spruce ◽  
Spatial Resolution ◽  
Lignin Content ◽  
Force Microscopy ◽  
Transmission Electron ◽  
High Resolution Images ◽  
The Individual ◽  
20 Nm

AbstractInfrared photo-induced force microscopy (IR PiFM) was applied for imaging ultrathin sections of Norway spruce (Picea abies) at 800–1885 cm−1 with varying scanning steps from 0.6 to 30 nm. Cell wall sublayers were visualized in the low-resolution mode based on differences in their chemical composition. The spectra from the individual sublayers demonstrated differences in the orientation of cellulose elementary fibrils (EFs) and in the content and structure of lignin. The high-resolution images revealed 5–20 nm wide lignin-free areas in the S1 layer. Full spectra collected from a non-lignified spot and at a short distance apart from it verified an abrupt change in the lignin content and the presence of tangentially oriented EFs. Line scans across the lignin-free areas corresponded to a spatial resolution of ≤ 5 nm. The ability of IR PiFM to resolve structures based on their chemical composition differentiates it from transmission electron microscopy that can reach a similar spatial resolution in imaging ultrathin wood sections. In comparison with Raman imaging, IR PiFM can acquire chemical images with ≥ 50 times higher spatial resolution. IR PiFM is also a surface-sensitive technique that is important for reaching the high spatial resolution in anisotropic samples like the cell wall. All these features make IR PiFM a highly promising technique for analyzing the recalcitrant nature of lignocellulosic biomass for its conversion into various materials and chemicals. Graphic abstract

High-resolution transmission electron microscopic investigations of molybdenum thin films on faceted α-Al2O3

2005 ◽  
Vol 38 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Leonore Wiehl ◽  
Jens Oster ◽  
Michael Huth
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Epitaxial Relationship ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
High Resolution Images ◽  
Α Al2o3 ◽  
Relationship Of

Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundummsurface was determined.

scholarly journals Chemical composition, anatomy, lignin distribution, and cell wall structure of Malaysian plant waste fibers

BioResources ◽  
2006 ◽  
Vol 1 (2) ◽  
pp. 220-232 ◽  
Author(s):  
H. P. S. Abdul Khalil ◽  
M. Siti Alwani ◽  
A. K. Mohd Omar
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Chemical Composition ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Anatomical Characteristics ◽  
Lignin Distribution ◽  
Transmission Electron ◽  
Palm Frond

The chemical composition, anatomical characteristics, lignin distribution, and cell wall structure of oil palm frond (OPF), coconut (COIR), pine-apple leaf (PALF), and banana stem (BS) fibers were analyzed. The chemical composition of fiber was analyzed according to TAPPI Methods. Light microscopy (LM) and transmission electron microscopy (TEM) were used to observe and determine the cell wall structure and lignin distribution of various agro-waste fibers. The results revealed differences in anatomical characteristics, lignin distributions, and cell wall structure of the different types of fibers investigated. Nevertheless, transmission electron microscopy (TEM) micrographs have confirmed that the well wall structure, in each case, could be described in terms of a classical cell wall structure, consisting of primary (P) and secondary (S 1 , S 2 , and S 3 ) layers.

scholarly journals Polymerized small molecular acceptor based all-polymer solar cells with an efficiency of 16.16% via tuning polymer blend morphology by molecular design

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiaqi Du ◽  
Ke Hu ◽  
Jinyuan Zhang ◽  
Lei Meng ◽  
Jiling Yue ◽  
...  
Keyword(s):  
Solar Cells ◽  
Molecular Design ◽  
Polymer Solar Cells ◽  
Energy Levels ◽  
Photovoltaic Performance ◽  
Electronic Energy ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Electronic Energy Levels ◽  
20 Nm

AbstractAll-polymer solar cells (all-PSCs) based on polymerized small molecular acceptors (PSMAs) have made significant progress recently. Here, we synthesize two A-DA’D-A small molecule acceptor based PSMAs of PS-Se with benzo[c][1,2,5]thiadiazole A’-core and PN-Se with benzotriazole A’-core, for the studies of the effect of molecular structure on the photovoltaic performance of the PSMAs. The two PSMAs possess broad absorption with PN-Se showing more red-shifted absorption than PS-Se and suitable electronic energy levels for the application as polymer acceptors in the all-PSCs with PBDB-T as polymer donor. Cryogenic transmission electron microscopy visualizes the aggregation behavior of the PBDB-T donor and the PSMA in their solutions. In addition, a bicontinuous-interpenetrating network in the PBDB-T:PN-Se blend film with aggregation size of 10~20 nm is clearly observed by the photoinduced force microscopy. The desirable morphology of the PBDB-T:PN-Se active layer leads its all-PSC showing higher power conversion efficiency of 16.16%.

Study of Photovoltaic Devices with Hybrid Active Layer

2019 ◽  
Vol 293 ◽  
pp. 51-64
Author(s):  
Pawel Jarka ◽  
Tomasz Tański ◽  
Bartlomiej Hrapkowicz ◽  
Barbara Hajduk ◽  
Kamil Bystroń ◽  
...  
Keyword(s):  
Optical Properties ◽  
Bulk Heterojunction ◽  
Photovoltaic Cells ◽  
Deposition Process ◽  
Thin Layers ◽  
Force Microscopy ◽  
Active Layers ◽  
Transmission Electron ◽  
Current Voltage ◽  
The Individual

The aim of this work is to present the influences of composition of the material and manufacturing technology conditions of the organic photovoltaics devices (OPv) with the organic and hybrid bulk heterojunction on the active layers properties and cells performance. The layers were produced by using small molecular compounds: the metal-phthalocyanine (MePc) and perylene derivatives (PTCDA) and the titanium dioxide (TiO2) nanoparticles. Two kinds of metal phthalocyanines (NiPc, TiOPc) were used as donor material and pperylenetetracarboxylic dianhydride (PTCDA) as an acceptor. The used manufacturing technique allowed to employ thin layers of materials in a fast deposition process. Bulk heterojunction was created by simultaneously applying the MePc:PTCDA materials during the evaporation of the components mixture.The research was based on the estimate of composition of bulk heterojunction, the examination of the surface morphology of the used layers and optical properties studies of the heterojunction and its implementation to photovoltaic architecture. The produced photovoltaic cells parameters were determined on the basis of current - voltage characteristics.The researches of structure of obtained layers were conducted by using scanning electron microscope (SEM) and transmission electron microscopy (TEM). The quantitative determination of surface topography by determining RMS and Ra coefficients were performed by atomic force microscopy (AFM). In order to determine the optical properties of the films the UV-Visible spectroscope have been utilized. Current - voltage characteristics were employed to determine the basic photovoltaic parameters using a dedicated device.The paper describes the influence of the individual components sharing the bulk heterojunction on its structure, optical properties and morphology of surface. In addition it allows for linking active layers properties with the parameters of the photovoltaic cells. The obtained results suggest the possibility of developing the utilized materials and technology in the further works on photovoltaic structures.

Comparison of Aluminum Nitride Nanowire Growth with and without Catalysts via Chemical Vapor Deposition

2011 ◽  
Vol 1324 ◽  
Author(s):  
Kasif Teker ◽  
Joseph A. Oxenham
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Systematic Investigation ◽  
Efficient Catalyst ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Direct Nitridation ◽  
20 Nm

ABSTRACTThis paper presents a systematic investigation of AlN nanowire synthesis by chemical vapor deposition using Al and NH3 on SiO2/Si substrate and direct nitridation of mixture of Al-Al2O3 by NH3. A wide variety of catalyst materials, in both discrete nanoparticle and thin film forms, have been used (Co, Au, Ni, and Fe). The growth runs have been carried out at temperatures between 800 and 1100oC mainly under H2 as carrier gas. It was found that the most efficient catalyst in terms of nanowire formation yield was 20-nm Ni film. The AlN nanowire diameters are about 20-30 nm, about the same thickness as the Ni-film. Further studies of direct nitridation of mixture of Al-Al2O3 by NH3 have resulted in high density one-dimensional nanostructure networks at 1100oC. It was observed that catalyst-free nanostructures resulted from the direct nitridation were significantly longer than that with catalysts. The analysis of the grown nanowires has been carried out by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and x-ray diffraction.

Mechanical Stress, Grain-boundary Relaxation, and Oxidation of Sputtered CuNi(Mn) Films

1999 ◽  
Vol 14 (4) ◽  
pp. 1286-1294 ◽  
Author(s):  
W. Brückner ◽  
W. Pitschke ◽  
S. Baunack ◽  
J. Thomas
Keyword(s):  
Grain Boundary ◽  
Microstructural Characterization ◽  
Excess Vacancy ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Boundary Relaxation ◽  
20 Nm ◽  
Atomic Rearrangement

This paper focuses on understanding stress development in CuNi42Mn1 thin films during annealing in Ar. In addition to stress-temperature measurements, resistance-temperature investigations and chemical and microstructural characterization by Auger electron spectroscopy, scanning and transmission electron microscopy, x-ray diffraction, and atomic force microscopy were also carried out. The films are polycrystalline with a grain size of 20 nm up to 450 °C. To explain the stress evolution above 120 °C, atomic rearrangement (excess-vacancy annihilation, grain-boundary relaxation, and shrinkage of grain-boundary voids) and oxidation were considered. Grain-boundary relaxation was found to be the dominating process up to 250–300 °C. A sharp transition from compressive to tensile stress between 300 and 380 °C is explained by the formation of a NiO surface layer due to reaction with the remaining oxygen in the Ar atmosphere. This oxidation is masking the inherent structural relaxation above 300 °C.

scholarly journals Nanoscale Infrared Spectroscopy Reveals Nanoplastics at 5000 m Depth in the South Atlantic Ocean

2021 ◽  
Author(s):  
Bert Weckhuysen ◽  
Iris ten Have ◽  
Florian Meirer ◽  
Ramon Oord ◽  
Erik Zettler ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Atlantic Ocean ◽  
Spatial Resolution ◽  
Analytical Techniques ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Chemical Information ◽  
The South ◽  
Force Microscopy ◽  
20 Nm

Abstract Millimeter- and micrometer-sized plastics are well-documented in aquatic ecosystems, but little is known about sub-micrometer particles because conventional analytical techniques lack sufficient spatial resolution or the spectroscopic means to unambiguously identify individual nanometer-sized plastic particles. We combined the spatial resolution of atomic force microscopy with chemical information from infrared spectroscopy to detect, identify, and count nanoplastics down to 20 nm in diameter in samples from different depths in the South Atlantic Ocean. We present evidence for the presence of polyethylene terephthalate (PET) nanoplastics in different states of degradation at 5000 m. Using lab-based ageing of PET, we demonstrate that nanoplastics can form even without light or interaction with the plastisphere, and that macroscopic PET items are a plausible source of PET nanoplastics in the ocean.

Nutritional characteristics of browse species from Northeastern Mexico consumed by small ruminants

2006 ◽  
Vol 34 ◽  
pp. 251-260
Author(s):  
Roque G. Ramírez-Lozano
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Medicago Sativa ◽  
Condensed Tannins ◽  
Lignin Content ◽  
Small Ruminants ◽  
Climatic Conditions ◽  
Browse Species ◽  
Northeastern Mexico ◽  
Nutrient Profiles

SummaryMany browse plants that grow in northeastern Mexico are consumed by domestic and wild range small ruminants. However, their nutritional value is determined by their chemical composition and digestibility. Chemical composition depends on the nature of the plant, but climatic conditions determine leaf maturity. Thus, studies to estimate the seasonality of the nutrient profiles of forages from shrubs are necessary. This paper has the objective to discuss the nutrient profiles and the organic matter digestion from the forage of 32 browse plants (13 legumes and 19 non legumes), that grow in northeastern México, and which are consumed by range small ruminants. Browses such as Acacia berlandieri (L.) Wild Acacia rigidula Benth., Ziziphus obtusifolia T and G., Desmanthus virgathus L. and Cercidium macrum I.M. Johnst. are the most abundant in the range, and also are the most selected by ruminants. The seasonal crude protein (CP) content in browse species varied within a range of 4.0 to 22.0%. The cell wall (from 24 to 53%) and its components: cellulose (from 5 to 31%) and hemicellulose (from 2 to 28%) also varied, and in most evaluated shrubs were lower than Medicago sativa hay. Seasonal lignin content also varied among plants species (from 1 to 24%; annual mean), and was higher than Medicago sativa hay. Condensed tannins were low and seasonally variable in most plants (from 0 to 23%). In general, during winter OMD (ranging from 30 to 68%) was higher than in other seasons. Lignin and condensed tannins negatively affected OMD (r = -0.40; P<0.01 and r = -0.53; P<0.001, respectively). The most selected shrubs were those with the highest tannin content. All plants were low in P and Na relative to the needs of adult goats, sheep and white-tailed deer. It is concluded that the chemical composition and OMD of browse plants were very similar among seasons. Because of their high CP, low cell wall, high mineral content and OMD in all plants, these could be considered as good protein supplements for range small grazing ruminants. However, they must be supplemented with P and Na throughout the year.

scholarly journals The Nature and Origin of Lateral Composition Modulations in Short-Period Strained-Layer Superlattices

1999 ◽  
Vol 583 ◽  
Author(s):  
A. G. Norman ◽  
S. P. Ahrenkiel ◽  
H. R. Moutinho ◽  
C. Ballif ◽  
M. M. Al-Jassim ◽  
...  
Keyword(s):  
Mole Fraction ◽  
Great Promise ◽  
Strained Layer ◽  
Force Microscopy ◽  
Growth Plane ◽  
Transmission Electron ◽  
Inp Substrate ◽  
Short Period ◽  
The Individual ◽  
Strained Layer Superlattices

AbstractThe nature and origin of lateral composition modulations in (AlAs)m(InAs)n short-period strained-layer superlattices grown by molecular beam epitaxy on InP substrates have been investigated by x-ray diffraction, atomic force microscopy, and transmission electron microscopy. Strong modulations were observed for growth temperatures between ≈ 540 and 560° C. The maximum strength of modulations was found for SPS samples with InAs mole fraction x (= n/(n+m)) close to ≈ 0.50 and when n ≈ m ≈ 2. The modulations were suppressed at both high and low values of x. For x > 0.52 (global compression), the modulations were along the <100> directions in the (001) growth plane. For x < 0.52 (global tension), the modulations were along the two <310> directions rotated ≈ ±27° from [110] in the growth plane. The remarkably constant wavelength of the modulations, between ≈ 20–30 nm, and the different modulation directions observed, suggest that the origin of the modulations is due to surface roughening associated with the high misfit between the individual SPS layers and the InP substrate. Highly uniform unidirectional modulations have been grown by control of the InAs mole fraction and growth on suitably offcut substrates, which show great promise for application in device structures.

Growth of Epitaxial 2H-silicon Carbide by Pulsed Laser Deposition

1994 ◽  
Vol 339 ◽  
Author(s):  
Mark A. Stan ◽  
Martin O. Patton ◽  
Hemasiri K. M. Vithana ◽  
David L. Johnson ◽  
Joseph D. Warner ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Average Diameter ◽  
Laser Deposition ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Columnar Grains ◽  
20 Nm ◽  
Heater Plate

ABSTRACTSilicon carbide films have been grown on 6H-SiC (0001) and Si (001) wafers by laser ablation using an excimer laser. The films were deposited at heater plate temperatures between 970° C to 1270° C. Film composition, morphology and polytypism were determined by Auger electron spectroscopy, atomic force microscopy and high resolution transmission electron microscopy (TEM). In the course of these experiments growth of 2H-SiC on 6H-SiC was observed at the highest heater plate temperatures. Cross-sectional TEM images clearly show the symmetry of a film grown at 1270° C as c-axis oriented 2H-SiC containing columnar grains with average diameter of 20 nm and length of 100 nm.

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