Host−Guest Interactions and Crystalline Structure Evolution in Clathrate Phases Formed by Syndiotactic Polystyrene and 1,2-Dichloroethane:  A Two-Dimensional FTIR Spectroscopy Investigation

2005 ◽  
Vol 38 (14) ◽  
pp. 6079-6089 ◽  
Author(s):  
Pellegrino Musto ◽  
Paola Rizzo ◽  
Gaetano Guerra
Keyword(s):  
Ftir Spectroscopy ◽  
Crystalline Structure ◽  
Structure Evolution ◽  
Syndiotactic Polystyrene ◽  
Two Dimensional

The extracellular matrix of echinoderm and amphibian eggs: Visualization in quick-frozen, deep-etched, and rotary-shadowed specimens

1990 ◽  
Vol 48 (3) ◽  
pp. 60-61
Author(s):  
Barry Bonnell ◽  
Carolyn Larabell ◽  
Douglas Chandler
Keyword(s):  
Extracellular Matrix ◽  
Plasma Membrane ◽  
Sea Urchin ◽  
Crystalline Structure ◽  
Cortical Granule ◽  
Two Dimensional ◽  
Small Peptides ◽  
Deep Etching ◽  
Quick Freezing ◽  
Acrosomal Reaction

Eggs of many species including those of echinoderms, amphibians and mammals exhibit an extensive extracellular matrix (ECM) that is important both in the reception of sperm and in providing a block to polyspermy after fertilization.In sea urchin eggs there are two distinctive coats, the vitelline layer which contains glycoprotein sperm receptors and the jelly layer that contains fucose sulfate glycoconjugates which trigger the acrosomal reaction and small peptides which act as chemoattractants for sperm. The vitelline layer (VL), as visualized by quick-freezing, deep-etching, and rotary-shadowing (QFDE-RS), is a fishnet-like structure, anchored to the plasma membrane by short posts. Orbiting above the VL are horizontal filaments which are thought to anchor the thicker jelly layer to the egg. Upon fertilization, the VL elevates and is transformed by cortical granule secretions into the fertilization envelope (FE). The rounded casts of microvilli in the VL are transformed into angular peaks and the envelope becomes coated inside and out with sheets of paracrystalline protein having a quasi-two dimensional crystalline structure.

Pore Structure Evolution of Cemented Paste Backfill Observed with Two-Dimensional NMR Relaxation Correlation Measurements

2021 ◽  
Vol 60 (36) ◽  
pp. 13253-13264
Author(s):  
Neil Robinson ◽  
Razyq Nasharuddin ◽  
Ganhua Luo ◽  
Andy Fourie ◽  
Einar O. Fridjonsson ◽  
...  
Keyword(s):  
Pore Structure ◽  
Nmr Relaxation ◽  
Structure Evolution ◽  
Two Dimensional ◽  
Cemented Paste Backfill ◽  
Paste Backfill

Stability progress of perovskite solar cells dependent on the crystalline structure: From 3D ABX3 to 2D Ruddlesden–Popper perovskite absorbers

2019 ◽  
Vol 7 (11) ◽  
pp. 5898-5933 ◽  
Author(s):  
Farzaneh Arabpour Roghabadi ◽  
Maryam Alidaei ◽  
Seyede Maryam Mousavi ◽  
Tahereh Ashjari ◽  
Ali Shokrolahzadeh Tehrani ◽  
...  
Keyword(s):  
Solar Cells ◽  
Crystalline Structure ◽  
Perovskite Solar Cells ◽  
Two Dimensional ◽  
3 Dimensional

This review presents the progress of the change of the PSK structure from 3 dimensional CH3NH3PbX3 to mixed cations or halides based PSKs and finally to Ruddlesden–Popper PSK two dimensional (2D) homologous structures regarding the lifetime improvement.

scholarly journals Simultaneous small-angle neutron scattering and Fourier transform infrared spectroscopic measurements on cocrystals of syndiotactic polystyrene with polyethylene glycol dimethyl ethers

2016 ◽  
Vol 49 (5) ◽  
pp. 1420-1427 ◽  
Author(s):  
Fumitoshi Kaneko ◽  
Naoki Seto ◽  
Shuma Sato ◽  
Aurel Radulescu ◽  
Maria Maddalena Schiavone ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Fourier Transform ◽  
Polyethylene Glycol ◽  
Temperature Region ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Room Temperature ◽  
Syndiotactic Polystyrene ◽  
Crystalline Region ◽  
Two Dimensional

Syndiotactic polystyrene (sPS) is a crystalline polymer which has a unique property; it is able to form cocrystals with a wide range of chemical compounds, in which the guest molecules are confined in the vacancies of the host sPS crystalline region. Recently, it has been found that even polyethylene glycol oligomers with a molecular weight of more than several hundreds can be introduced into the sPS crystalline region. It is quite important to know how such a long-chain molecule is stored in the host sPS lattice. To tackle this issue, a new simultaneous measurement method combing small-angle neutron scattering and Fourier transform infrared spectroscopy (SANS/FTIR), which has been recently developed by the authors, was applied to an sPS cocrystal with polyethylene glycol dimethyl ether with a molecular weight of 500 (PEGDME500). The temperature-dependent changes of the SANS profile and FTIR spectrum were followed from room temperature up to 413 K for a one-dimensionally oriented SANS/PEGDME500 cocrystal sample. The intensity of the reflections due to the stacking of crystalline lamellae showed a significant temperature dependence. The two-dimensional pattern in the high Q region of SANS also changed depending on temperature. The combined information obtained by SANS and FTIR suggested that PEGDME500 molecules are distributed in both the crystalline and amorphous regions in the low-temperature region close to room temperature, but they are predominantly included in the amorphous region in the high-temperature region. It was also suggested by the two-dimensional SANS profile that PEGDME500 molecules in the crystalline region have an elongated structure along the thickness direction of the crystalline lamellae.

New understanding on the reaction pathways of the polyacrylonitrile copolymer fiber pre-oxidation: online tracking by two-dimensional correlation FTIR spectroscopy

RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 4397-4409 ◽  
Author(s):  
Jing Zhao ◽  
Jihai Zhang ◽  
Tao Zhou ◽  
Xifei Liu ◽  
Qiang Yuan ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Ftir Spectroscopy ◽  
Reaction Pathways ◽  
Two Dimensional ◽  
Online Tracking ◽  
Polyacrylonitrile Copolymer ◽  
2D Correlation Analysis

FTIR spectroscopy in combination with scaling-MW2D and 2D correlation analysis is used to study the reaction pathways of polyacrylonitrile copolymer fibers pre-oxidation.

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