Journal: Environmental Science & Technology

Article Title: Armoring of MgO by a Passivation Layer Impedes Direct Air Capture of CO 2

doi: 10.1021/acs.est.3c04690

Figure Lengend Snippet: Characterization of the short-term experiments. (a) Light microscopy image of the measurement location of Raman spectra displayed in panel b for MgO reacted for 189 days with atmosphere. (c) TEM–BF image of MgO reacted for 167 days with atmosphere showing pristine MgO and small, newly formed crystallites. (d) Electron diffraction pattern of panel c. (e and f) FFT of areas highlighted in panel c, indicating single-crystal MgO and a new polycrystalline phase. Calculated d spacings indicate that this is most likely brucite. Diffraction spots stem from bulk MgO. (g) TEM–BF image of the reaction layer on MgO after 167 days of exposure to ambient air. (h) STEM–EELS imaging area shown for (i) carbon and (j) oxygen.

Article Snippet: The scanning transmission electron microscopy electron energy loss spectroscopy (STEM–EELS) experiments were performed using a Gatan Quantum EEL spectrometer with a dispersion of 0.3 eV/channel.

Techniques: Light Microscopy, Imaging

Journal: Heliyon

Article Title: Structure of polymeric nanoparticles encapsulating a drug – pamoic acid ion pair by scanning transmission electron microscopy

doi: 10.1016/j.heliyon.2023.e16959

Figure Lengend Snippet: Cryo-ADF-STEM micrograph of polymeric nanoparticles showing bright central regions in the core of some nanoparticles (green arrows) that might suggest a high density region within an inner core of the nanoparticles. (a)–(b) comparison between under-focus BF-TEM and ADF-STEM of the same region. Yellow curves indicate layer 1 and orange curves indicate layer 2. (c) A dark halo is visible around the particles in the ADF-STEM image (blue arrow and curves) suggesting the presence of layer 3 and it being lower density than the core and the surrounding vitreous ice. d) Application of a high pass filter to the ADF-STEM image removes thickness variation and emphasizes the low electron density of layer 3 and e) inverting the contrast of the high pass filtered ADF-STEM image reveals all three layers of the core-shell-corona nanoparticles. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Article Snippet: Cryo-STEM-EELS spectrum imaging was undertaken using the Gatan Quantum 965 ER imaging filter in the image-coupled mode.

Techniques:

Journal: Heliyon

Article Title: Structure of polymeric nanoparticles encapsulating a drug – pamoic acid ion pair by scanning transmission electron microscopy

doi: 10.1016/j.heliyon.2023.e16959

Figure Lengend Snippet: (a) Under-focus BF-TEM image and PCA treated carbon STEM-EELS mapping of the area marked in red. (b) Under-focus BF-TEM, ADF-STEM and C- K EELS mapping of a cropped fragment marked in yellow in (a) and showing carbon presence between the particles, confirming the C-content to layer 3. The corresponding diameter of layer 1 + 2 is identical between cropped under-focus BF-TEM, ADF-STEM and C- K map images (yellow arrows) and the thickness of layer 3 is consistent with earlier measurements of the spacing between nanoparticles by under-focus BF-TEM (blue arrow). Red arrows indicate severe electron beam damage in layer 2 visible in a post-EELS acquisition, ADF-STEM image. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Article Snippet: Cryo-STEM-EELS spectrum imaging was undertaken using the Gatan Quantum 965 ER imaging filter in the image-coupled mode.

Techniques:

Journal: Heliyon

Article Title: Structure of polymeric nanoparticles encapsulating a drug – pamoic acid ion pair by scanning transmission electron microscopy

doi: 10.1016/j.heliyon.2023.e16959

Figure Lengend Snippet: (a) Cryo-ADF-STEM image of particles and areas where spectra were extracted from – layer 1 (yellow box), layer 2 (orange boxes), layer 3 (blue boxes) and amorphous ice (purple box). (b) Background stripped, as-acquired (faint dots) and smoothed (bold lines) STEM-EELS from layer 1, layer 2 layer 3 and amorphous ice areas in (a). Layer 1 is C rich and also has a clear N peak identifiable. Layer 2 and 3 have progressively less C and relatively more O per layer and less than that of the amorphous ice. (c) Background stripped, as-acquired (faint lines) and smoothed (bold lines) STEM-EELS at the C- K edge reveal that layer 2 and layer 3 have slightly different edge structure to that of layer 1 suggesting a different polymer composition. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Article Snippet: Cryo-STEM-EELS spectrum imaging was undertaken using the Gatan Quantum 965 ER imaging filter in the image-coupled mode.

Techniques:

Journal: Heliyon

Article Title: Structure of polymeric nanoparticles encapsulating a drug – pamoic acid ion pair by scanning transmission electron microscopy

doi: 10.1016/j.heliyon.2023.e16959

Figure Lengend Snippet: (a) Cryo-ADF STEM and cryo-STEM EELS carbon and nitrogen mapping. (b) Cryo-STEM-EEL spectrum acquired over the whole area shows the presence of C, N and O. (c) A linear intensity profile taken from the C–N overlay map and ADF-STEM image indicates that C occurs also between the nanoparticles and N is located approximately in the centre of individual nanoparticles (yellow box in (a)). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Article Snippet: Cryo-STEM-EELS spectrum imaging was undertaken using the Gatan Quantum 965 ER imaging filter in the image-coupled mode.

Techniques:

Journal: Heliyon

Article Title: Structure of polymeric nanoparticles encapsulating a drug – pamoic acid ion pair by scanning transmission electron microscopy

doi: 10.1016/j.heliyon.2023.e16959

Figure Lengend Snippet: (a) Under-focus BF-TEM of non-standard nanoparticles named as: debris (non-spherical particles, marked as orange arrows) and blank (no visible layer 1, marked as red arrows). Both non-standard particles are highly beam sensitive. (b) Cropped cryo-STEM-EELS mapping of area marked in yellow in (a) suggests that debris and blank particles consist of the same material as layer 2 in the standard particle (i.e., have negligible N content and are highly beam sensitive). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Article Snippet: Cryo-STEM-EELS spectrum imaging was undertaken using the Gatan Quantum 965 ER imaging filter in the image-coupled mode.

Techniques:

Journal: Heliyon

Article Title: Structure of polymeric nanoparticles encapsulating a drug – pamoic acid ion pair by scanning transmission electron microscopy

doi: 10.1016/j.heliyon.2023.e16959

Figure Lengend Snippet: (a) Final multi-modal data-driven model of the polymeric nanoparticles based on (i) ADF-STEM (*high-pass filtered), (ii) phase contrast-TEM and (iii) STEM-EELS analysis. (b) The likely content of each layer is -pamoic acid-API and some PLA material in layer 1 with a core enriched in pamoic acid-API material. Only PEG and PLA in layer 2 and diffuse PEG packing in layer 3.

Article Snippet: Cryo-STEM-EELS spectrum imaging was undertaken using the Gatan Quantum 965 ER imaging filter in the image-coupled mode.

Techniques:

Journal: Nature Communications

Article Title: Vacancy driven surface disorder catalyzes anisotropic evaporation of ZnO (0001) polar surface

doi: 10.1038/s41467-022-33353-2

Figure Lengend Snippet: a STEM-HAADF image showing the (0001) surface covered by quasi-liquid layer at 300 °C. b , Composite image constructed by selecting EELS Zn-L 2,3 and O-K edges. The region marked by I, II, III and IV indicates the bulk ZnO, subsurface Zn 1- x O, the quasi-liquid layer and vacuum, respectively. c Averaged composition profiles of Zn and O from the white lined box in a and b obtained by quantification of EELS data (solid symbols). The composition profiles obtained by quantification STEM EDS data by using Zn-K α and O-K α peaks are included (open symbols). For more details, refer to Supplementary Fig. and Supplementary Note . Both EELS and EDS results consistently show that the quasi-liquid layer (region III) and subsurface (region II) are deficient of Zn, of which averaged Zn:O ratio is 0.2:0.8 and 0.4:0.6, respectively. The vacuum area with noise signal in b and c are shaded. d Atomic model depicting the calculated Zn and O desorption energy for the (0001), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(10\bar{1}1)$$\end{document} ( 10 1 ¯ 1 ) , and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(10\bar{1}0)$$\end{document} ( 10 1 ¯ 0 ) surfaces. Grey and red circles represent Zn and O, respectively. The desorption energies are calculated by applying the density functional theory (DFT) at 0 K. e Energy variation of V Zn along the diffusion path from the ((0001), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(10\bar{1}1)$$\end{document} ( 10 1 ¯ 1 ) , and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(10\bar{1}0)$$\end{document} ( 10 1 ¯ 0 ) surface towards the inner layers indicated as the solid arrow in d , which are calculated by the nudged elastic band method. Solid circles connected by solid line are the relative energy of the relaxed structure with V Zn on each layer; open circles connected by dash line are the energy variations in the transient structures.

Article Snippet: STEM EELS Zn-L 2,3 and O-K edges were obtained at 300 kV using an EEL spectrometer (Gatan GIF Quantum ER 965, USA) with an energy resolution of 0.7 eV.

Techniques: Construct, Functional Assay, Diffusion-based Assay