Surface Chemistry of Eucalyptus Wood Pulp Fibres: Effects of Chemical Pulping

Holzforschung ◽  
2002 ◽  
Vol 56 (6) ◽  
pp. 615-622 ◽  
Author(s):  
P. Fardim ◽  
N. Durán
Keyword(s):  
Contact Angle ◽  
Surface Chemistry ◽  
Surface Coverage ◽  
Wood Pulp ◽  
Work Of Adhesion ◽  
Sodium Salts ◽  
Tof Sims ◽  
Eucalyptus Wood ◽  
Chemical Pulping ◽  
Pulp Fibres

Summary The surface chemistry of Eucalyptus grandis wood pulp fibres was investigated using the sessile drop apparent contact angle, XPS and TOF-SIMS techniques. Pulp fibres were studied using different chemical pulping conditions. The pulping affected the surface coverage of lignin and extractives, as indicated by XPS, and the work of adhesion with water, as estimated from contact angle determinations. The amount of surface lignin decreased while surface extractives and work of adhesion with water increased in relation to the amount of active alkali used in the pulping. Desorption and analysis of surface extractives by TOF-SIMS showed sterols, fatty acid calcium and sodium salts. After acetone extraction the spectra obtained by TOF-SIMS showed changes. However, calcium and sodium salts of fatty acids were still detected, indicating their resistance to solvent extraction. This resistance to extraction can affect the lignin and extractive surface coverage estimations using XPS due to the contribution of the carbon content after extraction. The extent of interference was, however, uncertain.

scholarly journals In situ SEM micro-indentation of single wood pulp fibres in transverse direction

2010 ◽  
Vol 59 (5) ◽  
pp. 345-349 ◽  
Author(s):  
R.-B. Adusumalli ◽  
R. Raghavan ◽  
P. Schwaller ◽  
T. Zimmermann ◽  
J. Michler
Keyword(s):  
Transverse Direction ◽  
Wood Pulp ◽  
Pulp Fibres ◽  
Micro Indentation

Application of principal component analysis and tof-sims to mineral recognition, surface chemistry and separation by flotation

2006 ◽  
Vol 70 (18) ◽  
pp. A597 ◽  
Author(s):  
Roger St. C. Smart ◽  
Brian Hart ◽  
Mark Biesinger ◽  
James Francis ◽  
Tesfaye Negeri
Keyword(s):  
Principal Component Analysis ◽  
Surface Chemistry ◽  
Principal Component ◽  
Component Analysis ◽  
Tof Sims

scholarly journals Effect of Pesticide Addition Sequence on the Preparation of Phytosanitary Spray Solutions

2019 ◽  
Vol 37 ◽  
Author(s):  
M.F.T. RAMOS ◽  
R.T.S. SANTOS ◽  
D.P. ALMEIDA ◽  
J.F.D. VECHIA ◽  
M.C. FERREIRA
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Propionic Acid ◽  
Biological Effect ◽  
Surface Coverage ◽  
Mineral Oil ◽  
Application Rate ◽  
Physicochemical Interactions ◽  
Effect Of Treatment ◽  
Droplet Method

ABSTRACT: The addition of adjuvants to herbicide solutions is aimed at preserving or enhancing the biological effect of treatment. However, it is commonly performed without knowledge of the physicochemical interactions between products. This study aimed to assess the effects of different addition sequences of the herbicide aminopyralid + fluroxypyr and adjuvants in the preparation of phytosanitary spray solutions on the surface tension and contact angle. Two experiments were carried out with herbicide doses of 1 and 2 L ha-1 associated with the adjuvants mineral oil (MO), silicone-polyether copolymer (SIL), and a mixture of phosphatidylcholine (lectin) and propionic acid (LEC), all at a proportion of 0.3% v v-1. The application rate was 150 L ha-1. Surface tension was measured by the pendant droplet method. Contact angle was measured on the adaxial and abaxial surfaces of leaves of the pasture weed Senna obtusifolia and parafilm. Preparation sequence did not change the contact angle on any of the analyzed surfaces at a dose of 1 L ha-1 of herbicide. For the dose of 2 L ha-1, the adjuvants SIL and LEC showed a higher spreading when previously added to the herbicide. MO resulted in a higher spreading when added after the herbicide, with higher surface coverage. Therefore, the preparation sequence influences the dispersion of phytosanitary spray solutions on targets.

scholarly journals Applications of ToF-SIMS in surface chemistry analysis of lignocellulosic biomass: A review

BioResources ◽  
2016 ◽  
Vol 11 (2) ◽  
pp. 5581-5599
Author(s):  
Hong Yan Mou ◽  
Shubin Wu ◽  
Pedro Fardim
Keyword(s):  
Surface Chemistry ◽  
Lignocellulosic Biomass ◽  
Secondary Ion Mass Spectrometry ◽  
Critical Factor ◽  
Tof Sims ◽  
Biomass Components ◽  
Current Article ◽  
Sims Analysis ◽  
Secondary Ion

Time-of-flight secondary-ion mass spectrometry (ToF-SIMS) is an advanced surface-sensitive technique that can provide both spectral and imaging information about materials. Recently, ToF-SIMS has been used for advanced studies of lignocellulosic biomass. In the current article, the application of ToF-SIMS to the characterization of the surface chemical composition and distribution of biomass components in lignocelluloses is reviewed. Moreover, extended applications of ToF-SIMS in the study of pretreatments, modification of biomaterials, and enzyme activity of lignocellulosic materials are presented and discussed. Sample preparation prior to ToF-SIMS analysis and subsequent interpretation of results is a critical factor in ensuring reliable results. The focus of this review is to give a comprehensive understanding of and offer new hints about the effects of processing conditions on the surface chemistry of lignocellulosic biomass.

Relationship between Work of Adhesion and Contact Angle Hysteresis on Superhydrophobic Surfaces

2008 ◽  
Vol 112 (30) ◽  
pp. 11403-11407 ◽  
Author(s):  
Yonghao Xiu ◽  
Lingbo Zhu ◽  
Dennis W. Hess ◽  
C. P. Wong
Keyword(s):  
Contact Angle ◽  
Contact Angle Hysteresis ◽  
Superhydrophobic Surfaces ◽  
Work Of Adhesion

scholarly journals Evaluating the Surface Free Energy and Moisture Sensitivity of Warm Mix Asphalt Binders Using Dynamic Contact Angle

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Muhammad Rafiq Kakar ◽  
Meor Othman Hamzah ◽  
Mohammad Nishat Akhtar ◽  
Junita Mohamad Saleh
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Moisture Damage ◽  
Warm Mix Asphalt ◽  
Work Of Adhesion ◽  
Moisture Sensitivity ◽  
Modified Binders ◽  
Production Temperature

From the environmental conservation perspective, warm mix asphalt is more preferable compared to hot mix asphalt. This is because warm mix asphalt can be produced and paved in the temperature range 20–40°C lower than its equivalent hot mix asphalt. In terms of cost-effectiveness, warm mix asphalt can significantly improve the mixture workability at a lower temperature and thus reduce greenhouse gas emissions, to be environment friendly. However, the concern, which is challenging to warm mix asphalt, is its susceptibility to moisture damage due to its reduced production temperature. This may cause adhesive failure, which could eventually result in stripping of the asphalt binder from the aggregates. This research highlights the significance of Cecabase warm mix additive to lower the production temperature of warm mix asphalt and improvise the asphalt binder adhesion properties with aggregate. The binders used in the preparation of the test specimen were PG-64 and PG-76. The contact angle values were measured by using the dynamic Wilhelmy plate device. The surface free energy of Cecabase-modified binders was then computed by developing a dedicated algorithm using the C++ program. The analytical measurements such as the spreadability coefficient, work of adhesion, and compatibility ratio were used to analyze the results. The results inferred that the Cecabase improved the spreadability of the asphalt binder over limestone compared to the granite aggregate substrate. Nevertheless, the Cecabase-modified binders improved the work of adhesion. In terms of moisture sensitivity, it is also evident from the compatibility ratio indicator that, unlike granite aggregates, the limestone aggregates were less susceptible to moisture damage.

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