Solvent swelling behaviour of Shenmu-Fugu and Shengli coals

AbstractMicrolevel properties such as mineralogical and chemical compositions greatly control the macro behaviour of expansive soils. In this paper, the combined effect of mineral (i.e. montmorillonite, MMC) and chemical contents (i.e. Ca and Na in their total (T), leachable (L) and exchangeable form (CEC)) on swelling behaviour is investigated in a comprehensive way. Several 3-dimensional (3D) graphs correlating MMC and Ca/Na ratio, together, with swelling property (swelling potential, Sa, and swelling pressure, Sp) are developed. 3D plots, in general, portrayed a non-linear relationship of Sa and Sp with MMC and Ca/Na ratio, together. It is hypothesized that swelling initially is triggered by chemical parameters due to their quick and rapid ionization capability, but the overall swelling phenomenon is largely controlled by MMC. It is importantly found that expansive soils are dominant with divalent Ca++ ions up to MMC of 67% and beyond this percentage, monovalent Na+ ions are prevalent. From the interpretation of results, the maximum Sa of 18% and Sp of 93 kPa is measured at MMC of 43%, (Ca/Na)T of 10–14 and (Ca/Na)L of 2–7. It is concluded from study that total CEC + MMC for determining Sa and (Ca/Na)T + MMC for determining Sp are superior parameters to be considered. The findings of the study also excellently endorsed the results of Foster32, who stated that ionization of Na or Ca depends on the constituent mineral contents. The findings presented herein are unique, interesting and bear very practical significance, as no earlier research work reported such findings by accounting for chemical and mineralogical parameters impact, in tandem, on swelling properties.

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The Interplay between Drug and Sorbitol Contents Determines the Mechanical and Swelling Properties of Potential Rice Starch Films for Buccal Drug Delivery

Polymers ◽

10.3390/polym13040578 ◽

2021 ◽

Vol 13 (4) ◽

pp. 578

Author(s):

Bilal Harieth Alrimawi ◽

May Yee Chan ◽

Xin Yue Ooi ◽

Siok-Yee Chan ◽

Choon Fu Goh

Keyword(s):

Drug Delivery ◽

Drug Release ◽

Physicochemical Characteristics ◽

Rice Starch ◽

Swelling Behaviour ◽

Swelling Properties ◽

Buccal Drug Delivery ◽

Swelling Characteristics ◽

Starch Films ◽

Film Development

Rice starch is a promising biomaterial for thin film development in buccal drug delivery, but the plasticisation and antiplasticisation phenomena from both plasticisers and drugs on the performance of rice starch films are not well understood. This study aims to elucidate the competing effects of sorbitol (plasticiser) and drug (antiplasticiser) on the physicochemical characteristics of rice starch films containing low paracetamol content. Rice starch films were prepared with different sorbitol (10, 20 and 30% w/w) and paracetamol contents (0, 1 and 2% w/w) using the film casting method and were characterised especially for drug release, swelling and mechanical properties. Sorbitol showed a typical plasticising effect on the control rice starch films by increasing film flexibility and by reducing swelling behaviour. The presence of drugs, however, modified both the mechanical and swelling properties by exerting an antiplasticisation effect. This antiplasticisation action was found to be significant at a low sorbitol level or a high drug content. FTIR investigations supported the antiplasticisation action of paracetamol through the disturbance of sorbitol–starch interactions. Despite this difference, an immediate drug release was generally obtained. This study highlights the interplay between plasticiser and drug in influencing the mechanical and swelling characteristics of rice starch films at varying concentrations.

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Machine Learning Solvation Environments in Conductive Polymers: Application to ProDOT-2Hex with Solvent Swelling

Macromolecules ◽

10.1021/acs.macromol.0c02132 ◽

2021 ◽

Author(s):

Ioan-Bogdan Magdău ◽

Thomas F. Miller

Keyword(s):

Machine Learning ◽

Conductive Polymers ◽

Solvent Swelling

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Effect of polypropylene fibre on swelling behaviour of black cotton soil

Materials Today Proceedings ◽

10.1016/j.matpr.2020.09.356 ◽

2020 ◽

Author(s):

Tharini ◽

Nasar Ali ◽

Victor Samson Raj ◽

Anto ◽

Srinivasan

Keyword(s):

Polypropylene Fibre ◽

Black Cotton Soil ◽

Swelling Behaviour

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Swelling pressure and microstructure of an activated swelling clay with temperature

Clay Minerals ◽

10.1180/000985598545615 ◽

1998 ◽

Vol 33 (2) ◽

pp. 255-267 ◽

Cited By ~ 20

Author(s):

D. Tessier ◽

M. Dardaine ◽

A. Beaumont ◽

A. M. Jaunet

Keyword(s):

Room Temperature ◽

Swelling Pressure ◽

Radioactive Waste Disposal ◽

Basic Medium ◽

Hydraulic Pressure ◽

Swelling Behaviour ◽

Transmission Electron ◽

Ca Ions ◽

Na Ions ◽

Marked Drop

AbstractClay from Fourges has been selected by the Commissariat à l'Energie Atomique as a support in radioactive waste disposal studies. This material was activated by adding Na2CO3, then compacted at 60 MPa. Subsequently, its swelling behaviour was monitored at 90°C and 145°C for 330 days and at the end of this period the samples were examined by transmission electron microscopy (TEM). For this, they were embedded in a resin then sectioned with an ultramicrotome for mineralogical and chemical analyses. The initial material is essentially composed of kaolinite and smectite. Addition of Na2CO3 at room temperature induces a replacement of Ca ions by Na ions and the precipitation of finely divided carbonates on the surface of the constituents. At the end of 330 days at 90°C under a hydraulic pressure of 1 MPa, the initial particles combine and the material exerts a swelling pressure of 20 MPa. A complete reorganisation of the clay crystallites is observed without significant dissolution of the solid phases. After the same time at 145°C under a hydraulic pressure of 10 MPa, in a basic medium, the combined conditions are such that a high proportion of the clay is dissolved with formation of amorphous aluminosilicates correlated with a marked drop in the swelling pressure to 5 MPa. This work establishes the advantages of following the macroscopic properties in parallel with the microstructure variations for understanding the changes in the properties of clays.

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