The Influence of Monomer Structure on the Properties of Ionogels Obtained by Thiol–Ene Photopolymerization

The influence of ene and thiol monomer structure on the mechanical and electrochemical properties of thiol–ene polymeric ionogels were investigated. Ionogels were obtained in situ by thiol–ene photopolymerization of 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATT), 2,4,6-triallyloxy-1,3,5-triazine (TAT), diallyl phthalate (DAP), and glyoxal bis(diallyl acetal) (GBDA) used as enes and trimethylolpropane tris(3-mercaptopropionate) (TMPTP), pentaerythritol tetrakis(3-mercaptopropionate) (PETMP), and pentaerythritol tetrakis(3-mercaptobutyrate) (PETMB) used as thiols in 70 wt.% of ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImNTf2). The mechanical strength of ionogels was studied by puncture resistance and ionic conductivity by electrochemical impedance spectroscopy. The course of photopolymerization by photo-DSC method (differential scanning calorimetry) as well as characterization of compositions and its components (by IR and UV spectroscopy-Kamlet–Taft parameters) were also studied. The resulting ionogels were opaque, with phase separation, which resulted from the dispersion mechanism of polymerization. The mechanical and conductive properties of the obtained materials were found to be largely dependent on the monomer structure. Ionogels based on triazine monomers TAT and TATT were characterized by higher mechanical strength, while those based on aliphatic GBDA had the highest conductivity. These parameters are strongly related to the structure of the polymer matrix, which is in the form of connected spheres. The conductivity of ionogels was high, in the range of 3.5–5.1 mS∙cm−1.

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Effect of polyaniline/organophilic montmorillonite composites on properties of epoxy coating

Corrosion Reviews ◽

10.1515/corrrev-2014-0025 ◽

2014 ◽

Vol 32 (5-6) ◽

pp. 227-236 ◽

Cited By ~ 3

Author(s):

Yingjun Zhang ◽

Jingwei Deng ◽

Yawei Shao ◽

Qiumei Shi ◽

Guozhe Meng ◽

...

Keyword(s):

Epoxy Resin ◽

Electrochemical Impedance ◽

Epoxy Coating ◽

X Ray Diffraction ◽

Hydrophobic Property ◽

Scanning Calorimetry ◽

Composite Powders ◽

Organophilic Montmorillonite ◽

Intercalation Polymerization

AbstractPolyaniline/organophilic montmorillonite (PANI/OMMT) composite powders were synthesized by in situ intercalation polymerization and were added to the epoxy coating as an anti-corrosive pigment. Fourier translation infrared spectroscopy (FT-IR), X-ray diffraction, and contact angle test were used to characterize the PANI/OMMT powders. The epoxy coating containing the PANI/OMMT powders was studied by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and pull-off adhesion test. The results indicated that a unique combination of OMMT and PANI was realized by in situ intercalation polymerization, that the hydrophobic property of PANI/OMMT powders was enhanced and PANI/OMMT powders had good compatibility with epoxy resin, and that the anti-corrosive property of PANI/OMMT coating was better than that of epoxy resin coating.

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Optimization of the Properties of Photocured Hydrogels for Use in Electrochemical Capacitors

Polymers ◽

10.3390/polym13203495 ◽

2021 ◽

Vol 13 (20) ◽

pp. 3495

Author(s):

Piotr Gajewski ◽

Aneta Lewandowska ◽

Katarzyna Szcześniak ◽

Grzegorz Przesławski ◽

Agnieszka Marcinkowska

Keyword(s):

Mechanical Properties ◽

Polymer Electrolytes ◽

Electrochemical Impedance ◽

Electrochemical Capacitor ◽

Optimization Methods ◽

Scanning Calorimetry ◽

Acid Phosphate ◽

Conductive Properties ◽

Photopolymerization Kinetics ◽

Hydrogel Polymer

In this work, hydrogel polymer electrolytes (HPEs) were obtained by the photopolymerization of a mixture of two monomers: Exothane 8 (Ex8) and 2-hydroxyethylmethacrylate acid phosphate (HEMA-P) in an organic solvent N-methyl-2-pyrrolidone (NMP), which was replaced after polymerization with water, and then with the electrolyte. The ratio of monomers as well as the concentration of NMP was changed in the composition to study its influence on the properties of the HPE: conductivity (electrochemical impedance spectroscopy, EIS) and mechanical properties (puncture resistance). Properties were optimized using a mathematical model to obtain a hydrogel with both good mechanical and conductive properties. To the best of our knowledge, it is the first publication that demonstrates the application of optimization methods for the preparation of HPE. Then, the hydrogel with optimal properties was tested as a separator in a two-electrode symmetric AC/AC pouch-cell. The cells were investigated by cyclic voltammetry galvanostatic charge/discharge with potential limitation and EIS. Good mechanical properties of HPE allowed for obtaining samples of smaller thickness while maintaining very good dimensional stability. Thus, the electrochemical capacitor (EC) resistance was reduced and their electrochemical properties improved. Moreover, photopolymerization kinetics in the solvent and in bulk by photo-DSC (differential scanning calorimetry) were performed. The great impact on the polymerization of HEMA-P and its mixtures (with Ex8 and NMP) have strong intermolecular interactions between reagents molecules (i.e., hydrogen bonds).

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Differentiated Scanning Calorimetry of Model Systems with Cocoa Butter

Food Industry ◽

10.29141/2500-1922-2020-5-2-4 ◽

2020 ◽

Vol 5 (2) ◽

pp. 29-36

Author(s):

Alexander Vereshchagin ◽

Irina Reznichenko ◽

Nikolay Bychin

Keyword(s):

Cocoa Butter ◽

Palm Olein ◽

Palm Stearin ◽

Model Systems ◽

Scanning Calorimetry ◽

Glucose Syrup ◽

Polymorphic Modifications ◽

Confectionery Products ◽

System Temperature ◽

Dsc Method

The article concerns the research specificity of model systems such as cocoa butter – palm olein, cocoa butter – sucrose and cocoa butter – glucose syrup by the differential scanning calorimetry (DSC) method. The researchers run experiments in the temperature range from –100 to –50°C at a heating rate of 10 °C/min. In the cacao butter – palm olein system an eutectic occurs with a palm olein content of 30.0 % indicating the limited solubility of palm olein in cocoa butter. In the cocoa butter – sucrose system, cocoa butter crystallizes as in the α-form (10,0– 30,0; 60.0–90.0 % MK), and as a mixture of α-and β-forms of MK (40.0; 50,0; 70,0 and 80.0 %). Sucrose stabilizes low-temperature polymorphic modifications of cocoa butter. In the cocoa butter – glucose syrup system, temperature of samples melting is 21-22 °C. This composition is promising for use as a filling of confectionery products and glazes production. In this regard, a man can use glucose syrup only in the candy cases production. The role of surfactants used for the formation and stabilization of cocoa butter polymorphs and increasing the thermal stability of the shock-lad without the introduction of palm stearin requires separate consideration.

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Rigid PVC pipes. Differential scanning calorimetry (DSC) method

10.3403/30151901 ◽

2008 ◽

Keyword(s):

Differential Scanning Calorimetry ◽

Scanning Calorimetry ◽

Rigid Pvc ◽

Dsc Method

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Injectable in-situ Forming Depot Of Doxycycline Hyclate/α-Cyclodextrin Complex using PLGA for Periodontitis Treatment: Preparation, Charac-terization, and In-Vitro Evaluation

Current Drug Delivery ◽

10.2174/1567201817999201103195104 ◽

2020 ◽

Vol 17 ◽

Author(s):

Elham Khodaverdi ◽

Farhad Eisvand ◽

Mohammad Sina Nezami ◽

Seyedeh Nesa Rezaeian Shiadeh ◽

Hossein Kamali ◽

...

Keyword(s):

Complex Form ◽

Docking Studies ◽

Morphological Properties ◽

Burst Release ◽

Cyclodextrin Complex ◽

Doxycycline Hyclate ◽

Scanning Calorimetry ◽

In Situ Forming

Background:: Doxycycline (DOX) is used in treating a bacterial infection, especially for periodontitis treatment. Objective: To reduce irritation of DOX for subgingival administration and increase the chemical stability and against enzy-matic, the complex of α-cyclodextrin with DOX was prepared and loaded into injectable in situ forming implant based on PLGA. Methods:: FTIR, molecular docking studies, X-ray diffraction, and differential scanning calorimetry was performed to char-acterize the DOX/α-cyclodextrin complex. Finally, the in-vitro drug release and modeling, morphological properties, and cellular cytotoxic effects were also evaluated. Results:: The stability of DOX was improved with complex than pure DOX. The main advantage of the complex is the al-most complete release (96.31 ± 2.56 %) of the drug within 14 days of the implant, whereas in the formulation containing the pure DOX and the physical mixture the DOX with α-cyclodextrin release is reached to 70.18 ± 3.61 % and 77.03 ± 3.56 %, respectively. This trend is due to elevate of DOX stability in the DOX/ α-cyclodextrin complex form within PLGA implant that confirmed by the results of stability. Conclusion:: Our results were indicative that the formulation containing DOX/α-cyclodextrin complex was biocompatible and sustained-release with minimum initial burst release.

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Carbon Particle In-Situ Alloying of the Case-Hardening Steel 16MnCr5 in Laser Powder Bed Fusion

Metals ◽

10.3390/met11060896 ◽

2021 ◽

Vol 11 (6) ◽

pp. 896

Author(s):

Matthias Schmitt ◽

Albin Gottwalt ◽

Jakob Winkler ◽

Thomas Tobie ◽

Georg Schlick ◽

...

Keyword(s):

Laser Beam ◽

Mechanical Strength ◽

Carbon Content ◽

Metal Powder ◽

Case Hardening ◽

Powder Bed Fusion ◽

Powder Bed ◽

Carbon Particles ◽

Case Hardening Steel

The carbon content of steel affects many of its essential properties, e.g., hardness and mechanical strength. In the powder bed fusion process of metals using a laser beam (PBF-LB/M), usually, pre-alloyed metal powder is solidified layer-by-layer using a laser beam to create parts. A reduction of the carbon content in steels is observed during this process. This study examines adding carbon particles to the metal powder and in situ alloying in the PBF-LB/M process as a countermeasure. Suitable carbon particles are selected and their effect on the particle size distribution and homogeneity of the mixtures is analysed. The workability in PBF-LB is then shown. This is followed by an evaluation of the resulting mechanical properties (hardness and mechanical strength) and microstructure in the as-built state and the state after heat treatment. Furthermore, potential use cases like multi-material or functionally graded parts are discussed.

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Phase Transition and Coefficients of Thermal Expansion in Al2−xInxW3O12 (0.2 ≤ x ≤ 1)

Materials ◽

10.3390/ma14144021 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4021

Author(s):

Andrés Esteban Cerón Cerón Cortés ◽

Anja Dosen ◽

Victoria L. Blair ◽

Michel B. Johnson ◽

Mary Anne White ◽

...

Keyword(s):

Phase Transition ◽

Thermal Expansion ◽

Thermal Shock ◽

Monoclinic Phase ◽

Ceramic Materials ◽

Precipitation Method ◽

Scanning Calorimetry ◽

Orthorhombic Crystal ◽

Co Precipitation

Materials from theA2M3O12 family are known for their extensive chemical versatility while preserving the polyhedral-corner-shared orthorhombic crystal system, as well as for their consequent unusual thermal expansion, varying from negative and near-zero to slightly positive. The rarest are near-zero thermal expansion materials, which are of paramount importance in thermal shock resistance applications. Ceramic materials with chemistry Al2−xInxW3O12 (x = 0.2–1.0) were synthesized using a modified reverse-strike co-precipitation method and prepared into solid specimens using traditional ceramic sintering. The resulting materials were characterized by X-ray powder diffraction (ambient and in situ high temperatures), differential scanning calorimetry and dilatometry to delineate thermal expansion, phase transitions and crystal structures. It was found that the x = 0.2 composition had the lowest thermal expansion, 1.88 × 10−6 K−1, which was still higher than the end member Al2W3O12 for the chemical series. Furthermore, the AlInW3O12 was monoclinic phase at room temperature and transformed to the orthorhombic form at ca. 200 °C, in contrast with previous reports. Interestingly, the x = 0.2, x = 0.4 and x = 0.7 materials did not exhibit the expected orthorhombic-to-monoclinic phase transition as observed for the other compositions, and hence did not follow the expected Vegard-like relationship associated with the electronegativity rule. Overall, compositions within the Al2−xInxW3O12 family should not be considered candidates for high thermal shock applications that would require near-zero thermal expansion properties.

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Crystallization of Amorphous Silicon-Aluminum thin Films: IN-SITU Observation and Thermal Analysis.

MRS Proceedings ◽

10.1557/proc-237-609 ◽

1991 ◽

Vol 237 ◽

Cited By ~ 3

Author(s):

Toyohiko J. Konno ◽

Robert Sinclair

Keyword(s):

Activation Energy ◽

Amorphous Alloys ◽

Amorphous Matrix ◽

In Situ Observation ◽

Scanning Calorimetry ◽

Transmission Electron ◽

High Resolution Tem ◽

Higher Temperature ◽

Sputter Deposited

ABSTRACTThe crystallization of sputter-deposited Si/Al amorphous alloys was examined by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). In-situ high-resolution TEM reveals the existence of an Al layer between the amorphous matrix and the growing crystalline phase. The activation energy for the growth is about 1.2eV, roughly corresponding to the activation energy of Si diffusion in Al. These two observations support the view that a crystallization mechanism, in which an Al buffer layer provides the shortest reaction path, is responsible for the reaction. The product microstructure exhibits secondary crystallization at a higher temperature.

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