Cartilage polymers: From viscoelastic solutions to weak gels

2021 ◽  
Author(s):  
Ferenc Horkay ◽  
Jack F. Douglas
Keyword(s):  
Weak Gels

scholarly journals The Influence of the Addition of Nuts on the Thermal and Rheological Properties of Wheat Flour

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3969
Author(s):  
Karolina Pycia ◽  
Lesław Juszczak
Keyword(s):  
Rheological Properties ◽  
Wheat Flour ◽  
Viscoelastic Properties ◽  
Control Sample ◽  
Scanning Calorimetry ◽  
Creep And Recovery ◽  
Research Material ◽  
Pasting Characteristics ◽  
Tan Δ ◽  
Weak Gels

The aim of the study was to assess the influence of replacing wheat flour with hazelnuts or walnuts, in various amounts, on the thermal and rheological properties of the obtained systems. The research material were systems in which wheat flour was replaced with ground hazelnuts (H) or walnuts (W) in the amount of 5%, 10%, and 15%. The parameters of the thermodynamic gelatinization characteristics were determined by the differential scanning calorimetry method. In addition, the pasting characteristics were determined with the use of a viscosity analyzer and the viscoelastic properties were assessed. Sweep frequency and creep and recovery tests were used to assess the viscoelastic properties of the tested gels. It was found that replacing wheat flour with nuts increased the values of gelatinization temperature, gelatinization, and retrogradation enthalpy, and the degree of retrogradation. The highest viscosity was characteristic of the control sample (2039 mPa·s), and the lowest for the paste with 15% addition of walnuts (1120 mPa·s). Replacing the flour with nuts resulted in a very visible reduction in the viscosity of such systems. In addition, gels based on the systems with the addition of H and W were weak gels (tan δ = G″/G′ > 0.1), and the values of G′ and G″ parameters decreased with the increased share of nuts in the systems. Creep and recovery analysis indicated that the systems in which wheat flour was replaced with hazelnuts were less susceptible to deformation compared to the systems with the addition of W.

In situ crosslinked weak gels with ultralong and tunable gelation times for improving oil recovery

2021 ◽  
pp. 134350
Author(s):  
Hongyao Yin ◽  
Xin Yin ◽  
Ruibo Cao ◽  
Peiyun Zeng ◽  
Jing Wang ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Weak Gels

scholarly journals Tuning Gel State Properties of Supramolecular Gels by Functional Group Modification

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3472 ◽  
Author(s):  
Dipankar Ghosh ◽  
Matthew T. Mulvee ◽  
Krishna K. Damodaran
Keyword(s):  
Self Assembly ◽  
Thermal Stabilities ◽  
Factors Affecting ◽  
Sem Image ◽  
Group Modification ◽  
Fibrous Morphology ◽  
Low Molecular Weight Gelators ◽  
Functional Group Modification ◽  
Gel Network ◽  
Weak Gels

The factors affecting the self-assembly process in low molecular weight gelators (LMWGs) were investigated by tuning the gelation properties of a well-known gelator N-(4-pyridyl)isonicotinamide (4PINA). The N―H∙∙∙N interactions responsible for gel formation in 4PINA were disrupted by altering the functional groups of 4PINA, which was achieved by modifying pyridyl moieties of the gelator to pyridyl N-oxides. We synthesized two mono-N-oxides (INO and PNO) and a di-N-oxide (diNO) and the gelation studies revealed selective gelation of diNO in water, but the two mono-N-oxides formed crystals. The mechanical strength and thermal stabilities of the gelators were evaluated by rheology and transition temperature (Tgel) experiments, respectively, and the analysis of the gel strength indicated that diNO formed weak gels compared to 4PINA. The SEM image of diNO xerogels showed fibrous microcrystalline networks compared to the efficient fibrous morphology in 4PINA. Single-crystal X-ray analysis of diNO gelator revealed that a hydrogen-bonded dimer interacts with adjacent dimers via C―H∙∙∙O interactions. The non-gelator with similar dimers interacted via C―H∙∙∙N interaction, which indicates the importance of specific non-bonding interactions in the formation of the gel network. The solvated forms of mono-N-oxides support the fact that these compounds prefer crystalline state rather than gelation due to the increased hydrophilic interactions. The reduced gelation ability (minimum gel concentration (MGC)) and thermal strength of diNO may be attributed to the weak intermolecular C―H∙∙∙O interaction compared to the strong and unidirectional N―H∙∙∙N interactions in 4PINA.

Effects of shear fracture on in-depth profile modification of weak gels

2007 ◽  
Vol 4 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Li Xianjie ◽  
Song Xinwang ◽  
Yue Xiang’an ◽  
Hou Jirui ◽  
Fang Lichun ◽  
...  
Keyword(s):  
Depth Profile ◽  
Shear Fracture ◽  
Profile Modification ◽  
Weak Gels

Rheological and thermal stability of novel weak gels based on sulfonated polyacrylamide/scleroglucan/chromium triacetate

2016 ◽  
Vol 66 (3) ◽  
pp. 477-484 ◽  
Author(s):  
Ehsan Alvand ◽  
Jamal Aalaie ◽  
Mahmood Hemmati ◽  
Vali Ahmad Sajjadian
Keyword(s):  
Thermal Stability ◽  
Sulfonated Polyacrylamide ◽  
Thermal Stability Of ◽  
Weak Gels

scholarly journals Improving of Gelling Capacity of Cooked Crab Meat Proteins

2021 ◽  
Vol 8 ◽  
Author(s):  
Gabriela Nallely Trejo-Díaz ◽  
Miguel Ángel Martínez-Maldonado ◽  
Rocío M. Uresti-Marín ◽  
Gonzalo Velazquez ◽  
José Alberto Ramírez
Keyword(s):  
Mechanical Properties ◽  
Profile Analysis ◽  
Callinectes Sapidus ◽  
Textural Properties ◽  
Texture Profile ◽  
Microbial Enzyme ◽  
Mixing Method ◽  
Crab Meat ◽  
Cooked Meat ◽  
Weak Gels

Cooked crab meat subjected to a cutting process can aggregate again, forming weak gels. The objective of this work was to determine the effect of two mixing methods, combined with the addition of the microbial enzyme TGase (MTGase) on the mechanical and functional properties of gels from washed or unwashed blue crab (Callinectes sapidus) meat. Live crabs were obtained from Laguna Madre, Tamaulipas, Mexico, and cooked at 120°C for 20 min before hand-picking the meat from the shell. Cooked meat was processed by mixing and cut at temperatures of 25 or 60°C, without (control) or 0.5% of MTGase. Then cooked at 90°C for 15 min. Changes in texture profile analysis, percentage of extractable water, and color were evaluated. The mixing method at 60°C allowed increasing the textural properties of the gels, and the addition of MTGase significantly improved the mechanical properties. The results allowed stablishing a viable technique to obtain restructured gels from cooked crab meat with no need to extract the soluble compounds responsible for their distinctive odor and taste which often affect the mechanical properties.

Effects of heating and calcium and phosphate mineral supplementation on the physical properties of rennet-induced coagulation of camel and cow milk gels

2017 ◽  
Vol 84 (2) ◽  
pp. 220-228 ◽  
Author(s):  
Mohammad Kamal ◽  
Mohammed Foukani ◽  
Romdhane Karoui
Keyword(s):  
Physical Properties ◽  
Loss Modulus ◽  
Gelation Time ◽  
Camel Milk ◽  
Cow Milk ◽  
Mineral Supplementation ◽  
Phosphate Dihydrate ◽  
Phosphate Mineral ◽  
Low Amplitude ◽  
Weak Gels

The physical properties of rennet-induced coagulation of preheated camel and cow milk gels (50 and 70 °C for 10 min) enriched with calcium chloride (CaCl2) and hydrogen phosphate dihydrate (Na2HPO42H2O) were evaluated using the dynamic low amplitude oscillatory shear analysis. The storage modulus (Gʹ) and loss modulus (Gʺ) of camel milk gels showed significant (P < 0·05) lower values than those of cow milk gels. The preheating of camel milk at 50 °C affected negatively the gelation properties, while the preheating at 70 °C prevented the formation of rennet-induced milk gels. No effect was observed on the gelation properties of cow milk gels. The CaCl2 added at 10 and 20 mM to preheated camel and cow milk reduced significantly (P < 0·05) the gelation time and increased the gel firmness. In contrast, Na2HPO42H2O added at 10 and 20 mM induced the formation of weak gels for preheated camel and cow milk at 50 °C, and even no gelation for preheated camel milk at 70 °C.

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