scholarly journals Synthesis and Physicochemical Evaluation of Bees’ Chitosan-Based Hydrogels Modified with Yellow Tea Extract

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3379
Author(s):  
Sonia Kudłacik-Kramarczyk ◽  
Anna Drabczyk ◽  
Magdalena Głąb ◽  
Paweł Gajda ◽  
Anna Jaromin ◽  
...  
Keyword(s):  
Contact Angles ◽  
Structure Property ◽  
Swelling Properties ◽  
Structure Property Relationships ◽  
Physicochemical Evaluation ◽  
Measurement Methodology ◽  
Ft Ir ◽  
Tea Extract ◽  
The Impact ◽  
Dressing Materials

The novelty of the research involves designing the measurement methodology aimed at determining the structure–property relationships in the chitosan-based hydrogels containing yellow tea extract. Performed investigations allowed us to determine the swelling properties of hydrogels in selected time intervals, evaluate the mutual interactions between the hydrogels and simulated physiological liquids via pH measurements and directly assess the impact of such interactions on the chemical structure of hydrogels using Fourier transform infrared (FT-IR) spectroscopy and their wettability by the measurements of the flatness of the drop on the surface of the tested samples via the static drop method. Next, the surface morphology of hydrogels was characterized by the Scanning Electron Miscorcopy (SEM) and their elasticity under the tension applied was also verified. It was proved that incubation in simulated physiological liquids resulted in a decrease in contact angles of hydrogels, even by 60%. This also caused their certain degradation which was reflected in lower intensities of bands on FT-IR spectra. Further, 23% v/v yellow tea extract in hydrogel matrices caused the decrease of their tensile strength. An increase in the amount of the crosslinker resulted in a decrease in the sorption capacity of hydrogels wherein their modification caused greater swelling ability. In general, the investigations performed provided much information on the tested materials which may be meaningful considering their application, e.g., as dressing materials.

Structure–property relationships in hybrid (C3H5N2)3[Sb2I9] and (C3H5N2)3[Bi2I9] isomorphs

2016 ◽  
Vol 3 (10) ◽  
pp. 1306-1316 ◽  
Author(s):  
M. Węcławik ◽  
A. Gągor ◽  
R. Jakubas ◽  
A. Piecha-Bisiorek ◽  
W. Medycki ◽  
...  
Keyword(s):  
Proton Magnetic Resonance ◽  
Optical Observations ◽  
Structure Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Property Relationships ◽  
Hybrid Crystals ◽  
Ft Ir ◽  
Two Hybrid ◽  
Ft Ir Spectroscopy

Two hybrid crystals imidazolium iodoantimonate(iii) and iodobismuthate(iii) have been synthesized and characterized in a wide temperature range (100–350 K) by means of X-ray diffraction, dielectric spectroscopy, proton magnetic resonance, FT-IR spectroscopy and optical observations.

Investigating the impact of three-dimensional learning interventions on student understanding of structure–property relationships

2021 ◽  
Author(s):  
Sonia M. Underwood ◽  
Alex T. Kararo ◽  
Gabriela Gadia
Keyword(s):  
General Chemistry ◽  
Active Learning ◽  
Boiling Point ◽  
Three Dimensional ◽  
Intermolecular Forces ◽  
Control Group ◽  
Chemistry Curriculum ◽  
Structure Property ◽  
Structure Property Relationships ◽  
The Impact

The ability to predict macroscopic properties using a compound's chemical structure is an essential idea for chemistry as well as other disciplines such as biology. In this study we investigate how different levels of interventions impact the components of students’ explanations (claims, evidence, and reasoning) of structure–property relationships, particularly related to boiling point trends. These interventions, aligned with Three-Dimensional Learning (3DL), were investigated with four different cohorts of students: Cohort 1 – a control group of students enrolled in an active learning general chemistry course; Cohort 2 – students enrolled in the same active learning general chemistry course but given Intervention 1 (a 3DL worksheet administered during class time); Cohort 3 – students enrolled in the same active learning general chemistry course but given Intervention 1 and Intervention 2 (a 3DL course exam question administered after instruction); and Cohort 4 – a reference group of students enrolled in a transformed active learning general chemistry curriculum in which 3DL is an essential feature and includes Intervention 1 and Intervention 2 as part of the curriculum. We found that Cohort 2 students (with the 3DL worksheet intervention) were more likely than the control group (Cohort 1) to correctly predict the compound with a higher boiling point as well as incorporate ideas of strength of intermolecular forces into their explanations of boiling point differences. When a 3DL exam question was given as a follow up to the 3DL worksheet, students in Cohort 3 were more likely than Cohorts 1 and 2 to correctly identify the claim. Further comparison showed that Cohort 4 (transformed general chemistry curriculum) were more likely than Cohorts 1–3 to also include the ideas of energy needed to overcome stronger forces for a more sophisticated explanation (50% of Cohort 4 students compared to 17–33% for Cohorts 1–3). In addition, 80% of Cohort 4 students were able to construct a correct representation of hydrogen bonding as a non-covalent interaction compared to 13–57% for the other three cohorts.

scholarly journals Dynamic transformation of cubic copper catalysts during CO2 electroreduction and its impact on catalytic selectivity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Philipp Grosse ◽  
Aram Yoon ◽  
Clara Rettenmaier ◽  
Antonia Herzog ◽  
See Wee Chee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Copper Catalysts ◽  
Underlying Structure ◽  
Structure Property ◽  
Product Analysis ◽  
Time Resolved ◽  
Catalytic Selectivity ◽  
Structure Property Relationships ◽  
Co2 Electroreduction ◽  
The Impact

AbstractTo rationally design effective and stable catalysts for energy conversion applications, we need to understand how they transform under reaction conditions and reveal their underlying structure-property relationships. This is especially important for catalysts used in the electroreduction of carbon dioxide where product selectivity is sensitive to catalyst structure. Here, we present real-time electrochemical liquid cell transmission electron microscopy studies showing the restructuring of copper(I) oxide cubes during reaction. Fragmentation of the solid cubes, re-deposition of new nanoparticles, catalyst detachment and catalyst aggregation are observed as a function of the applied potential and time. Using cubes with different initial sizes and loading, we further correlate this dynamic morphology with the catalytic selectivity through time-resolved scanning electron microscopy measurements and product analysis. These comparative studies reveal the impact of nanoparticle re-deposition and detachment on the catalyst reactivity, and how the increased surface metal loading created by re-deposited nanoparticles can lead to enhanced C2+ selectivity and stability.

scholarly journals Physicochemical Investigations of Hydrogels Containing Gold Nanoparticles Designed for Biomedical Use

2021 ◽  
Vol 5 (2) ◽  
pp. 20-30
Author(s):  
Magdalena Głąb ◽  
Sonia Kudłacik-Kramarczyk ◽  
Anna Drabczyk ◽  
Beata Grabowska ◽  
Bożena Tyliszczak
Keyword(s):  
Arabic Gum ◽  
Wound Contamination ◽  
Application Potential ◽  
Ft Ir ◽  
Therapeutic Properties ◽  
Synthesis Methodology ◽  
The Impact ◽  
Dressing Materials ◽  
Positive Effect ◽  
External Barrier

Currently, many investigations are being performed to develop dressing materials with a positive effect on the wound healingprocess. In general, innovative dressings should ensure wound exudate absorption, constitute an external barrier limiting thepossibility of wound contamination and, importantly, also provide therapeutic properties. This work is focused on obtainingmaterials with potential use as dressings for treatment of difficult-to-heal wounds. The synthesis methodology of acrylic hydrogelsmodified with selected modifiers, i.e. arabic gum, nanogold, bee pollen and chamomile extract, was developed. Next, thesorption properties of the materials were determined as well as their behavior during the incubation in fluids imitating theenvironment of the human body. Additionally, the impact of such an incubation on their structure was evaluated by FT-IR spectroscopy.It was proved that the modifiers affected the sorption properties of hydrogels, i.e. samples with additives showed evenapprox. 2.5-fold lower swelling ability. In turn, incubation of hydrogels in simulated body fluids did not cause any rapid changesin pH, which may indicate the biocompatibility of the tested materials with the tested fluids. Thus, it may be concluded that thedeveloped materials show great application potential for biomedical purposes and may be subjected to more advanced studiessuch as cytotoxicity assessments towards selected cell lines.

Structure–Property Relationships in Sterically Congested Proton-Conducting Poly(phenylene)s: the Impact of Biphenyl Linearity

2020 ◽  
Vol 53 (8) ◽  
pp. 3119-3138 ◽  
Author(s):  
N. Peressin ◽  
M. Adamski ◽  
E. M. Schibli ◽  
E. Ye ◽  
B. J. Frisken ◽  
...  
Keyword(s):  
Structure Property ◽  
Proton Conducting ◽  
Structure Property Relationships ◽  
The Impact

scholarly journals Physicochemical Characteristics of Chitosan-Based Hydrogels Modified with Equisetum arvense L. (Horsetail) Extract in View of Their Usefulness as Innovative Dressing Materials

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7533
Author(s):  
Magdalena Głąb ◽  
Anna Drabczyk ◽  
Sonia Kudłacik-Kramarczyk ◽  
Marcel Krzan ◽  
Bożena Tyliszczak
Keyword(s):  
Chronic Wounds ◽  
Physicochemical Characteristics ◽  
Contact Angles ◽  
Equisetum Arvense ◽  
Hydrophilic Nature ◽  
Sorption Ability ◽  
Alkaline Environments ◽  
Application Potential ◽  
The Impact ◽  
Dressing Materials

This work focused on obtaining and characterizing hydrogels with their potential application as dressing materials for chronic wounds. The research included synthesizing chitosan-based hydrogels modified with Equisetum arvense L. (horsetail) extract via photopolymerization, and their characteristics determined with regard to the impact of both the modifier and the amount of crosslinker on their properties. The investigations included determining their sorption properties and tensile strength, evaluating their behavior in simulated physiological liquids, and characterizing their wettability and surface morphology. The release profile of horsetail extract from polymer matrices in acidic and alkaline environments was also verified. It was proved that hydrogels showed swelling ability while the modified hydrogels swelled slightly more. Hydrogels showed hydrophilic nature (all contact angles were <77°). Materials containing horsetail extract exhibited bigger elasticity than unmodified polymers (even by 30%). It was proved that the extract release was twice as effective in an acidic medium. Due to the possibility of preparation of hydrogels with specific mechanical properties (depending on both the modifier and the amount of crosslinker used), wound exudate sorption ability, and possibility of the release of active substance, hydrogels show a great application potential as dressing materials.

scholarly journals Synthesis and structure–property relationships of phthalimide and naphthalimide based organic π-conjugated small molecules

2016 ◽  
Vol 18 (21) ◽  
pp. 14709-14719 ◽  
Author(s):  
Abby-Jo Payne ◽  
Arthur D. Hendsbee ◽  
Seth M. McAfee ◽  
Devproshad K. Paul ◽  
Kunal Karan ◽  
...  
Keyword(s):  
Thin Films ◽  
Small Molecules ◽  
Chain Length ◽  
Side Chain ◽  
Structure Property ◽  
Side Chain Length ◽  
Materials Properties ◽  
Structure Property Relationships ◽  
And Topology ◽  
The Impact

Six organic π-conjugated small molecules with a bithiophene core and aryl imide terminal units are reported. The impact of alky side chain length and topology, and aryl imide size on materials properties in solution and as thin-films was investigated.

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