Lattice imaging of radiation‐sensitive polymer crystals

Tsuji, Masaki; Roy, Saroj K.; Manley, R. St. John

doi:10.1002/pol.1985.180230605

Cited by 17 publications

(14 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eventually, in the fifth scan, the spacing reached 0.43 nm or slightly larger, with similar spacing in the amorphous halo. This trend agreed well with the previously reported irradiation damage of PE single crystals …”

Section: Resultssupporting

confidence: 93%

“…The average number of electrons per second (8.7 × 10 6 e – /s) was used to calculate the electron dose. The electron irradiation dose (the number of irradiated electrons per unit area on the sample) has been discussed in numerous studies. − ,,,− Table S1 presents the experimental NDI parameters used in several papers, including ours. Two different types of doses were calculated: the dose per probe area ( D p ) and per scan step area ( D s ).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Nanodiffraction Imaging of Polymer Crystals

et al. 2021

View full text Add to dashboard Cite

Nanodiffraction imaging (NDI) is a novel imaging technique based on scanning transmission electron microscopy (STEM); it uses a nanometer-size electron beam to scan across a specimen, and the electron diffraction (ED) pattern at each position is recorded onto a two-dimensional (2D) pixelated detector. In this study, NDI was used to image the nanoscale spatial distribution and orientation of lamellar crystals of polyethylene (PE)one of the most popular and electron-beam-sensitive semicrystalline polymerswithout any pretreatment (e.g., RuO4 staining). 2D ED patterns as many as 1282 probe positions (over a scanning area of 3.842 μm2) were obtained for two PE samples featuring significantly different crystal orientations (non-oriented and oriented samples). Spot-like diffractions, corresponding to orthorhombic PE 110 and 200 peaks, were observed in numerous ED patterns, the detailed analysis of which provides the spatial distribution and orientation of lamellar crystals at nanometer resolutions. No distinct morphologies were observed under conventional STEM. A substantial difference between non-oriented and oriented samples was identified: the lamellae orientations of non-oriented samples were random, whereas those of oriented samples were uniform, with the c-axis aligned in the stretching direction. Furthermore, the local orientation fluctuation of the lamellar crystals in the oriented sample was clarified by NDI. Such local structural information is key to understanding higher-level hierarchical elements (e.g., spherulite and shish kebab) but cannot be obtained by conventional diffraction/scattering methods.

show abstract

Section: Resultssupporting

confidence: 93%

Section: Methodsmentioning

confidence: 99%

Nanodiffraction Imaging of Polymer Crystals

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Lattice images of Valonia cellulose microfibrils as well as those of other highly crystalline cellulose samples were soon produced in several laboratories. (Revol, 1985;Tsuji et al, 1985;Brown, 1987a, 1987b;Kuga and Brown, 1989;Chanzy, 1990;Helbert et al, 1998aHelbert et al, , 1998b. The data from electron diffraction diagrams and from images resulting from diffraction contrast have been decisive to reveal the cross-sectional shape of some of the cellulose microfibrils (Nishiyama, 2009).…”

Section: Cellulose With Diffraction Contrast and Low-dose Temmentioning

confidence: 99%

Transmission electron microscopy of cellulose. Part 1: historical perspective

2018

View full text Add to dashboard Cite

Following the first electron micrographs of cotton in 1940, the development of transmission electron microscopy applied to native cellulose has been evolving in a series of successive advances. At first, faced with the weak contrast of the early images, the operators had to use specific electron dense contrasting agents to reveal the ultrastructure of their samples.It was thus found that all native celluloses consisted of microfibrils, with some size variations depending on the sample origin. Following this, a major advance was achieved when the electron microscopes could be adjusted with low electron doses, allowing the recording of diffraction diagrams from the electron beam-sensitive cellulose samples. Under these conditions, one could obtain information of cellulose itself and not, as before, of the contrasting agent. This important development applied to microdiffraction conditions revealed that some large cellulose microfibrils could yield spot diagrams typical of single crystals. Their recording led to a decisive progress for resolving the molecular and crystal structure of the two cellulose allomorphs, cellulose Ia and Ib. Using various combinations of diffracted beams to create the images, the so called "diffraction contrast images" could then be developed. These micrographs showed many aspects of the crystalline core of cellulose, including spectacular high-resolution images showing the molecular planes of cellulose in their crystalline environment. Today, electron diffraction, diffraction contrast imaging and low-dose electron microscopy have become major tools to follow the effect of various physical, chemical and biochemical processes at the cellulose crystalline level.

show abstract

“…It is well known that cellulose is susceptible to electron radiation damage. The total end point dose of ramie cellulose (i. e., the electron irradiation dose necessary for complete destruction of the crystal latrice) has been estimated to be about 0.003 Coulomb/ cm 2 at 120 kV [11]. It is important to ascertain whether significant structural detail is lost at irradiation dose levels (such as used in the present work) that greatly exceed this value.…”

Section: Discussionmentioning

confidence: 98%

Image analysis in the electron microscopy of cellulose protofibrils II. Digital correlation methods

Tsuji

Frank

Manley

1986

Colloid & Polymer Sci

View full text Add to dashboard Cite

Electron micrographs of parallel arrays of negatively stained ramie cellulose protofibrils were analyzed using the two-dimensional digital autocorrelation function (ACF). The method is based upon the statistical analysis of images in real space. The ACF shows strong parallel streaks of high correlation, and the lateral distance between adjacent streaks allows the mean interfibrillar distance to be estimated as 3.7 nm. The intensity profile along the streaks shows a weak modulation with peaks occurring at integral multiples of 3 or 6 nm. These results provide direct evidence that there is a regular axial texture in the protofibrils, and corroborate the conclusions previously drawn from optical diffraction analysis. Using the difference vectors found in the ACF it has been possible to reduce the picture noise level by linear integration, thereby obtaining an enhanced image. A preliminary result obtained in this way suggests that the projected protofibril morphology associated with the observed axial periodicity is a ribbon-like zigzag structure. Possible applications of the method for future work are discussed.

show abstract

Lattice imaging of radiation‐sensitive polymer crystals

Cited by 17 publications

References 22 publications

Nanodiffraction Imaging of Polymer Crystals

Nanodiffraction Imaging of Polymer Crystals

Transmission electron microscopy of cellulose. Part 1: historical perspective

Image analysis in the electron microscopy of cellulose protofibrils II. Digital correlation methods

Contact Info

Product

Resources

About