An in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged archaeological wood

Holzforschung ◽  
2020 ◽  
Vol 74 (11) ◽  
pp. 1043-1051
Author(s):  
Åke Henrik-Klemens ◽  
Katarina Abrahamsson ◽  
Charlotte Björdal ◽  
Alexandra Walsh
Keyword(s):  
Polyethylene Glycol ◽  
Spectroscopic Method ◽  
Calibration Model ◽  
Efficient Treatment ◽  
Raman Spectroscopic ◽  
Archaeological Wood ◽  
Validation Set ◽  
Impregnation Period ◽  
Polymer Impregnation

AbstractThe weakened microstructure of archaeological wood (AW) objects from waterlogged environments necessitates consolidation to avoid anisotropic shrinkage upon drying. Polymer impregnation through submergence or spraying treatments is commonly applied, and for larger and thicker objects, the impregnation period can stretch over decades. Thus, for efficient treatment, continuous monitoring of the impregnation status is required. Today, such monitoring is often destructive and expensive, requiring segments for extraction and chromatographic quantification. This study proposes an in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged AW. A calibration model was built on standards of PEG, cellulose powder, and milled wood lignin using orthogonal partial least squares (OPLS). The OPLS model had a strong linear relationship, and the PEG content in wood of varying degrees of degradation could be determined. However, the accuracy of the model was low with a root mean square error of prediction of 11 wt%. The low accuracy was traced to the heterogeneity in the calibration and validation set samples with regard to the small probing volume of the confocal instrumental setup.

scholarly journals Evaluation of a Raman spectroscopic method for the determination of alcohol content in Greek spirit Tsipouro

2016 ◽  
Vol 4 (Special-Issue-October) ◽  
pp. 01-09 ◽  
Author(s):  
Christos Pappas ◽  
Basalekou Marianthi ◽  
Elina Konstantinou ◽  
Niki Proxenia ◽  
Stamatina Kallithraka ◽  
...  
Keyword(s):  
Spectroscopic Method ◽  
Alcohol Concentration ◽  
Calibration Model ◽  
Alcohol Content ◽  
Raman Spectroscopic ◽  
Band Area ◽  
Starting Point ◽  
Pre Treatment ◽  
Relative Errors

A Raman spectroscopic method and the conventional distillation method for the determination of alcohol content % (v/v) in Greek spirit Tsipouro used. A univariate calibration model was constructed employing the band area at 880 cm-1 of standard ethanol solutions. The concentrations of 46 samples were then measured using the calibration model and the results were compared with those obtained using the conventional analysis employing a distillation step. Alcohol content in Greek spirit Tsipouro measured with the conventional method ranged from 35.1 to 71.2 % (v/v). The determination coefficient (R2) value was 0.9997 while the corresponding values of the relative errors ranged between – 13.1 -1.0 %. According to the proposed method the alcohol concentration in Greek spirit Tsipouro ranged from 27.7 to 68.2 % (v/v). The proposed method is simple, rapid, economical and does not require any sample pre-treatment steps. It could be a starting point for the design of more specific models according to the requirements of the spirit industry.

Feasibility of Detecting Barrier Layer to Low-k Transition in Copper Cmp Using Raman Spectroscopy

2005 ◽  
Vol 867 ◽  
Author(s):  
S. Kondoju ◽  
C. Juncker ◽  
P. Lucas ◽  
S. Raghavan ◽  
P. Fischer ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Spectroscopic Method ◽  
Spectroscopic Techniques ◽  
Vibrational Modes ◽  
Si Substrate ◽  
Raman Spectroscopic ◽  
Barrier Layers ◽  
Copper Cmp ◽  
Low K

AbstractIn copper CMP, transitions from copper to barrier as well as barrier to dielectric layer are typically sensed in situ using an optical reflectance technique. Spectroscopic techniques such as Raman, which allow monitoring the vibrational modes of silicon and low-k layers, have interesting potential for detecting these transitions. In this paper the use of Raman spectroscopy in detecting in situ removal of barrier layers from CDO materials is reported. Intensities of Raman peaks characteristic of Si-Si vibrations from Si substrate and C-H vibrations from low-k materials have been used for monitoring CDO layer thickness and detecting removal of Ta overlayer. An abrasion cell is integrated with a Raman spectrometer to demonstrate the feasibility of Raman monitoring in-situ. Capabilities and limitations of the Raman spectroscopic method are discussed.

scholarly journals Conservation of Waterlogged Wood—Past, Present and Future Perspectives

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1193
Author(s):  
Magdalena Broda ◽  
Callum Hill
Keyword(s):  
Polyethylene Glycol ◽  
Chemical Composition ◽  
Soft Rot ◽  
Future Perspectives ◽  
Wood Degradation ◽  
Archaeological Wood ◽  
Waterlogged Archaeological Wood ◽  
In Situ Preservation

This paper reviews the degradation, preservation and conservation of waterlogged archaeological wood. Degradation due to bacteria in anoxic and soft-rot fungi and bacteria in oxic waterlogged conditions is discussed with consideration of the effect on the chemical composition of wood, as well as the deposition of sulphur and iron within the structure. The effects on physical properties are also considered. The paper then discusses the role of consolidants in preserving waterlogged archaeological wood after it is excavated as well as issues to be considered when reburial is used as a means of preservation. The use of alum and polyethylene glycol (PEG) as consolidants is presented along with various case studies with particular emphasis on marine artefacts. The properties of consolidated wood are examined, especially with respect to the degradation of the wood post-conservation. Different consolidants are reviewed along with their use and properties. The merits and risks of reburial and in situ preservation are considered as an alternative to conservation.

Thermal gravimetric analysis of in-situ crosslinked nanocellulose whiskers • poly(methyl vinyl ether-co-maleic acid) • polyethylene glycol

TAPPI Journal ◽  
2011 ◽  
Vol 10 (4) ◽  
pp. 29-33
Author(s):  
LEE A. GOETZ ◽  
AJI P. MATHEW ◽  
KRISTIINA OKSMAN ◽  
ARTHUR J. RAGAUSKAS
Keyword(s):  
Thermal Stability ◽  
Polyethylene Glycol ◽  
Vinyl Ether ◽  
Thermal Gravimetric Analysis ◽  
Maleic Acid ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Methyl Vinyl ◽  
Methyl Vinyl Ether

The thermal stability and decomposition of in-situ crosslinked nanocellulose whiskers – poly(methyl vinyl ether-co-maleic acid) – polyethylene glycol formulations (PMVEMA-PEG), (25%, 50%, and 75% whiskers) – were investigated using thermal gravimetric analysis (TGA) methods. The thermal degradation behavior of the films varied according to the percent cellulose whiskers in each formulation. The presence of cellulose whiskers increased the thermal stability of the PMVEMA-PEG matrix.

scholarly journals The Influence of Temperature and Viscosity of Polyethylene Glycol on the Rate of Microwave-Induced In Situ Amorphization of Celecoxib

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 110
Author(s):  
Nele-Johanna Hempel ◽  
Tra Dao ◽  
Matthias M. Knopp ◽  
Ragna Berthelsen ◽  
Korbinian Löbmann
Keyword(s):  
Polyethylene Glycol ◽  
Microwave Radiation ◽  
Magnesium Stearate ◽  
Einstein Equations ◽  
Dissolution Process ◽  
Target Temperature ◽  
Peg 4000 ◽  
Lower Viscosity ◽  
Model Drug

Microwaved-induced in situ amorphization of a drug in a polymer has been suggested to follow a dissolution process, with the drug dissolving into the mobile polymer at temperatures above the glass transition temperature (Tg) of the polymer. Thus, based on the Noyes–Whitney and the Stoke–Einstein equations, the temperature and the viscosity are expected to directly impact the rate and degree of drug amorphization. By investigating two different viscosity grades of polyethylene glycol (PEG), i.e., PEG 3000 and PEG 4000, and controlling the temperature of the microwave oven, it was possible to study the influence of both, temperature and viscosity, on the in situ amorphization of the model drug celecoxib (CCX) during exposure to microwave radiation. In this study, compacts containing 30 wt% CCX, 69 wt% PEG 3000 or PEG 4000 and 1 wt% lubricant (magnesium stearate) were exposed to microwave radiation at (i) a target temperature, or (ii) a target viscosity. It was found that at the target temperature, compacts containing PEG 3000 displayed a faster rate of amorphization as compared to compacts containing PEG 4000, due to the lower viscosity of PEG 3000 compared to PEG 4000. Furthermore, at the target viscosity, which was achieved by setting different temperatures for compacts containing PEG 3000 and PEG 4000, respectively, the compacts containing PEG 3000 displayed a slower rate of amorphization, due to a lower target temperature, than compacts containing PEG 4000. In conclusion, with lower viscosity of the polymer, at temperatures above its Tg, and with higher temperatures, both increasing the diffusion coefficient of the drug into the polymer, the rate of amorphization was increased allowing a faster in situ amorphization during exposure to microwave radiation. Hereby, the theory that the microwave-induced in situ amorphization process can be described as a dissolution process of the drug into the polymer, at temperatures above the Tg, is further strengthened.

scholarly journals Microwave-induced in situ drug amorphization using a mixture of polyethylene glycol and polyvinylpyrrolidone

2021 ◽  
Author(s):  
Nele-Johanna Hempel ◽  
Matthias M. Knopp ◽  
J. Axel Zeitler ◽  
Ragna Berthelsen ◽  
Korbinian Löbmann
Keyword(s):  
Polyethylene Glycol

In situ Raman Spectroscopic Observation of Polymer Chains in Semi-Crystalline Polyethylene Solids

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yusuke Hiejima ◽  
Takumitsu Kida ◽  
Koh-hei Nitta
Keyword(s):  
Conformational Changes ◽  
Tensile Elongation ◽  
Spectroscopic Observation ◽  
Polymer Chains ◽  
Trans Conformation ◽  
Raman Spectroscopic ◽  
Higher Temperature ◽  
Microscopic Origin ◽  
Crystalline Polyethylene

AbstractIn situ Raman spectroscopy is applied for polyethylene solid under various environments to elucidate the morphological and conformational changes. The trans conformation retains up to higher temperature for high-density polyethylene, reflecting higher stability of the orthorhombic crystals composed of stacked trans chains. It is suggested that the conversion of the non-crystalline trans chains to the crystalline phase is the microscopic origin of thermal history in the crystallinity, whereas the transformation between the trans and gauche conformers is practically in thermal equilibrium. Microscopic and dynamic mechanism of deformation during uniaxial stretching is investigated for the molecular orientation and the microscopic load sharing on the crystalline and amorphous chains. Lower crystallinity results in smoother and higher orientation toward the stretching direction, as well as higher load on the amorphous chains, during tensile elongation.

Sign in / Sign up

Export Citation Format

Share Document