Role of thermoxidation and depolymerisation in the ageing of systems paper/gum arabic/historical ink

2014 ◽  
Vol 68 (4) ◽  
Author(s):  
András Peller ◽  
Milena Reháková ◽  
Michaela Ciglanská ◽  
Peter Šimon
Keyword(s):  
Reaction Path ◽  
Gum Arabic ◽  
Thermal Ageing ◽  
Accelerated Ageing ◽  
Thermal Method ◽  
Reaction Paths ◽  
Thermal Methods ◽  
Iron Gall ◽  
A Minor ◽  
Whatman Paper

AbstractThe aim of this study was to assess the role and proportional representation of depolymerisation and thermoxidation reaction paths in the systems paper/gum arabic (GA)/historical ink during various accelerated ageing methods. The historical inks under study are iron-gall, bistre, and sepia. The results indicate that thermoxidation represents only a minor reaction path in the ageing of paper/GA/ink systems except for the iron-gall ink and the light-thermal method of accelerated ageing. The iron-gall ink accelerates both reaction paths of ageing, i.e. thermoxidation and depolymerisation; in this case, thermoxidation might become the prevailing degradation reaction path. For the sepia ink, an anti-depolymerisation stabilising effect in thermal methods of ageing has been detected. Considering the thermoxidation reaction path, the results even suggest that a compound preventing thermoxidation is formed during the thermally accelerated ageing in air and in 100 mg L−1 of NO2. In the light-thermal ageing, the most stable sample is the Whatman paper (W)/GA/bistre ink.

scholarly journals In-depth phenolic characterization of iron gall inks by deconstructing representative Iberian recipes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Natércia Teixeira ◽  
Paula Nabais ◽  
Victor de Freitas ◽  
João A. Lopes ◽  
Maria J. Melo
Keyword(s):  
Phenolic Compounds ◽  
Gum Arabic ◽  
White Wine ◽  
Molecular Structures ◽  
Phenolic Profile ◽  
Essential Information ◽  
History Of ◽  
Iron Gall ◽  
History Of Western Civilization

AbstractIron-gall ink is one of the most important inks in the history of western civilization. The deep black colour results from Fe3+ complexes with phenolic compounds available in gall extracts. Unfortunately, it induces the degradation of both ink and support over time. Furthermore, our knowledge of these complex molecular structures is limited. This work aims to overcome this gap, revealing essential information about the complex structures of these pigments and dyes that will create a breakthrough in the next generation of conservation treatments. It presents the first in-depth phenolic identification and quantification of extracts and inks, prepared with and without gum arabic (an essential additive in medieval recipes). Five representative Iberian recipes were selected and prepared. Their phenolic profile was analysed by HPLC–DAD and HPLC–ESI–MS, which revealed that the phenolic compounds present in higher concentration, in the gall extracts, are pentagalloylglucose and hexagalloylglucose (0.15 ± 0.01–32 ± 3 mg/mL), except for one recipe, in which gallic acid is the main phenolic. The influence of the ingredients is also discussed by deconstructing the recipes: extracts of additives as pomegranate peel and solvents used in the extraction of the galls (vinegar and white wine) were characterized.

scholarly journals Assessment of Nanocalcite Synthesis Routs on Green Biodiesel Production: Comparative Study

2020 ◽  
Vol 10 (5) ◽  
pp. 6139-6147
Keyword(s):  
Fossil Fuel ◽  
Sol Gel ◽  
Biodiesel Production ◽  
Thermal Method ◽  
Thermal Methods ◽  
Cooking Oil ◽  
The Past ◽  
Similar Vein ◽  
Egg Shell ◽  
Forward Process

There has been a large demand for producing and utilizing eco-friendly fuel during the past few decades. In this regard, proposing an alternative to fossil fuel has to be judged based on its availability, and sustainability. Biodiesel is one of the realistic candidates to be a fossil fuel substitute. Albeit, biodiesel production is not straight forward process as it involves a chemical reaction that necessitates the use of a catalyst. In current research, we synthesized calcite (CaCO/CaCO3) nanocatalysts were prepared using two common methods, namely, sol-gel and thermal method. The findings revealed that synthesized nanocatalyst by sol-gel method enhanced the biodiesel yield to 93% compare to 98% for nanocatalyst synthesized from egg shell by the thermal method. In a similar vein, the nanocatalysts manufactured by sol-gel and thermal methods were tested for their reusability and showed a 81%, and 88%, biodiesel yield respectively. Furthermore, the Cetane Index (CI) was measured to confirm the efficiency of the produced biodiesel which was within a recommended range of (45-54), suggestive that CaCO/CaCO3 nanocatalyst might be a good candidate for efficient and reasonably clean biodiesel production from cooking oil waste.

Kinetics and mechanisms of the reaction between carbon monoxide and copper(II) in aqueous solution

1969 ◽  
Vol 47 (2) ◽  
pp. 313-321 ◽  
Author(s):  
J. J. Byerley ◽  
E. Peters
Keyword(s):  
Aqueous Solution ◽  
Carbon Monoxide ◽  
Reaction Path ◽  
Carbonyl Complex ◽  
Cupric Ion ◽  
Inhibiting Effect ◽  
Rate Determining Step ◽  
Ph Dependent ◽  
A Minor ◽  
Kinetics Of

The kinetics of the reduction of copper(II) to copper(I) by carbon monoxide in aqueous solutions have been investigated at 120 °C and carbon monoxide pressures up to 1360 atm. The reaction is homogeneous and proceeds by two paths, one of which is virtually independent of carbon monoxide pressure due to the formation of a stable cuprous carbonyl complex Cu(CO)+. The second reaction path contains both a pH-dependent and pH-independent component. The rate-determining step in both paths appears to be the decomposition of a carbon monoxide insertion complex by a cupric ion. Complexing ligands such as acetate were observed to have a minor inhibiting effect on the overall reaction.

Interactions in iron gall inks

2007 ◽  
Vol 61 (5) ◽  
Author(s):  
V. Jančovičová ◽  
M. Čeppan ◽  
B. Havlínová ◽  
M. Reháková ◽  
Z. Jakubíková
Keyword(s):  
Complex Formation ◽  
Gallic Acid ◽  
Bathochromic Shift ◽  
Gum Arabic ◽  
Absorption Bands ◽  
Vis Spectroscopy ◽  
Concentration Changes ◽  
Iron Gall ◽  
Visible Area ◽  
Absorbance Band

AbstractSimple iron gall inks composed of gallic acid, ferrous sulfate, and gum arabic and in some cases also of copper(II) sulfate were prepared. The process of iron ion complex formation with gallic acid was investigated using UV-VIS spectroscopy, pH measurements, and by monitoring the concentration changes of Fe(II) ions. The admixture of Fe(II) ions to gallic acid induced a bathochromic shift of absorption bands at 215 nm and 265 nm in the UV-VIS spectra. Formation of a new absorbance band in the visible area was also observed and used to calculate the initial rate of complex formation. Concurrently, the pH values and the concentration of Fe(II) ions in the solution decreased. Gum arabic significantly enhanced the complex formation and its stability. On the contrary, the addition of Cu(II) ions to the solution decelerated the complex formation considerably.

The influence of pollutants on accelerated ageing of parchment with iron gall inks

2014 ◽  
Vol 15 (4) ◽  
pp. 373-381 ◽  
Author(s):  
Michaela Ciglanská ◽  
Viera Jančovičová ◽  
Bohuslava Havlínová ◽  
Zuzana Machatová ◽  
Vlasta Brezová
Keyword(s):  
Accelerated Ageing ◽  
Iron Gall

scholarly journals A method of measuring the effective resistance of a condenser at radio frequencies, and of measuring the resistance of long straight wires

1932 ◽  
Vol 137 (831) ◽  
pp. 116-133 ◽  
Keyword(s):  
Energy Loss ◽  
Resonance Method ◽  
Effective Resistance ◽  
Circular Disc ◽  
Solid Dielectric ◽  
Thermal Method ◽  
Thermal Methods ◽  
Elegant Method ◽  
Air Condenser ◽  
Total Capacity

When the effective resistance of a high frequency circuit is measured by a resonance method, it is usual to find that the resistance exceeds the calculated resistance of the coil. Some of the discrepancy may be due to energy loss in the condenser, and it is desirable to have some means of measuring this loss. The energy loss in high power condensers is now measured regularly by thermal methods and may be as small as 0·025 per cent. of the volt ampere product. But a thermal method is impracticable for the small condensers used in a laboratory because the power absorbed would be less than 0·1 W. Most of the energy loss in an air condenser is presumably due to the dielectric supporting the plates and to poor contacts between the plates. Dye has developed ma very elegant method for measuring the energy loss in a condenser, which presumes that all the loss occurs in the solid dielectric. In his method there is a special condenser which consists of two capacities in parallel, and screened from one another. One portion of this compound condenser contains the insulating supports for the second portion. Accordingly the second portion contains no solid dielectric and is a pure air condenser and is presumed to have no loss. This condenser consists of a single circular disc, which may have one of three sizes, contained within a cylindrical box; the plate hangs from a metal stem which is supported on quartz blocks contained in a chamber above the cylindrical box. The total capacity may be considered to be in two parts. One between the metal stem and the case and having a dielectric which is partly quartz and therefore imperfect; the other between the circular disc and the case and having no dielectric except air and therefore being perfect. The condenser to be tested can be connected in parallel with the special condenser and its capacity is adjusted to be equal to that between the circular disc and the case. The disc can be detached from the stem and so leave only the imperfect portion of the special condenser. The condenser under test is then placed in parallel with the imperfect portion, resulting in a total capacity unchanged by the substitution process. But the substitution has replaced a capacity without loss for an equal capacity with loss. The total circuit resistance is measured by a resonance method before and after the substitution and the difference of value is ascribed to the loss in the condenser under test. Since the special condenser is provided with three different discs the resistance of the condenser under test could be measured at three different settings.

scholarly journals Weathering of Antibacterial Melt-Spun Polyfilaments Modified by Pine Rosin

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 876
Author(s):  
Mikko Kanerva ◽  
Jacob Mensah-Attipoe ◽  
Arja Puolakka ◽  
Timo M. Takala ◽  
Marko Hyttinen ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Degradation Process ◽  
Thermal Ageing ◽  
Poly Lactic Acid ◽  
Accelerated Ageing ◽  
Functional Additives ◽  
Volatile Organic ◽  
Melt Spun ◽  
Over Time ◽  
Killing Response

For many antibacterial polymer fibres, especially for those with natural functional additives, the antibacterial response might not last over time. Moreover, the mechanical performance of polymeric fibres degrades significantly during the intended operation, such as usage in textile and industrial filter applications. The degradation process and overall ageing can lead to emitted volatile organic compounds (VOCs). This work focused on the usage of pine rosin as natural antibacterial chemical and analysed the weathering of melt-spun polyethylene (PE) and poly lactic acid (PLA) polyfilaments. A selected copolymer surfactant, as an additional chemical, was studied to better integrate rosin with the molecular structure of the plastics. The results reveal that a high 20 w-% of rosin content can be obtained by surfactant addition in non-oriented PE and PLA melt-spun polyfilaments. According to the VOC analysis, interestingly, the total emissions from the melt-spun PE and PLA fibres were lower for rosin-modified (10 w-%) fibres and when analysed below 60 ℃. The PE fibres of the polyfilaments were found to be clearly more durable in terms of the entire weathering study, i.e., five weeks of ultraviolet radiation, thermal ageing and standard washing. The antibacterial response against Gram-positive Staphylococcus aureus by the rosin-containing fibres was determined to be at the same level (decrease of 3–5 logs cfu/mL) as when using 1.0 w-% of commercial silver-containing antimicrobial. For the PE polyfilaments with rosin (10 w-%), full killing response (decrease of 3–5 logs cfu/mL) remained after four weeks of accelerated ageing at 60 ℃.

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