Decoupling the contribution of dispersive and acid-base components of surface energy on the cohesion of pharmaceutical powders

Surface free energy of composite and coatings are critically important for the performance of the materials since the change in surface free energies can drastically affect the physical, chemical and physicochemical properties, and hence the service life of them. The characterization of the surface free energy is the key issue to understand the mechanisms of the surface degradation. Acid-base interaction is one way of determining the surface free energy change on these surfaces. In the present study, we exposed composite and coating surfaces to UV light, and then measured the contact angle values using various liquids (e.g., DI water, diiodomethane and glycerol). Using the van Oss approach, we calculated the surface energy changes of the surfaces exposed to the UV light. We found that the surface energy, acidity and basicity of the composite and coating materials were drastically changed as a function of UV exposure time. This study can be useful for the moisture uptake of composites, composite degradation, aging and service life of these products.

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Decoupling the Contribution of Surface Energy and Surface Area on the Cohesion of Pharmaceutical Powders

Pharmaceutical Research ◽

10.1007/s11095-014-1459-3 ◽

2014 ◽

Vol 32 (1) ◽

pp. 248-259 ◽

Cited By ~ 18

Author(s):

Umang V. Shah ◽

Dolapo Olusanmi ◽

Ajit S. Narang ◽

Munir A. Hussain ◽

Michael J. Tobyn ◽

...

Keyword(s):

Surface Energy ◽

Surface Area ◽

Pharmaceutical Powders

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Effect of temperature on the surface free energy and acid–base properties of Gabapentin and Pregabalin drugs − a comparative study

RSC Advances ◽

10.1039/c5ra03032c ◽

2015 ◽

Vol 5 (60) ◽

pp. 48712-48719 ◽

Cited By ~ 6

Author(s):

S. Ramanaiah ◽

Vikram Karde ◽

P. Venkateswarlu ◽

Chinmay Ghoroi

Keyword(s):

Free Energy ◽

Surface Energy ◽

Comparative Study ◽

Surface Free Energy ◽

Effect Of Temperature ◽

Temperature Dependent ◽

Acid Base ◽

Base Properties

Temperature dependent surface energy variations observed in Gabapentin and Pregabalin drugs.

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EFFECT OF Nd:YAG LASER MELTING ON SURFACE ENERGY OF AZ91D Mg ALLOY

Surface Review and Letters ◽

10.1142/s0218625x09013347 ◽

2009 ◽

Vol 16 (06) ◽

pp. 801-806 ◽

Cited By ~ 14

Author(s):

Y. C. GUAN ◽

W. ZHOU ◽

H. Y. ZHENG

Keyword(s):

Contact Angle ◽

Surface Energy ◽

Laser Irradiation ◽

Contact Angle Measurement ◽

Angle Measurement ◽

Laser Surface ◽

Laser Melting ◽

Acid Base ◽

Az91d Magnesium Alloy ◽

Drastic Increase

Laser surface melting is known to alter surface energy and wettability of a few engineering materials, but its effect on magnesium alloys has never been reported. Effort was made to study how Nd : YAG laser irradiation influenced surface energy of an AZ91D magnesium alloy. Contact angle measurement was carried out using three types of liquids to make it possible to calculate the surface energy quantitatively based upon the acid–base theory. The laser irradiation was found to enhance surface wettability significantly and lead to a drastic increase in surface energy from 25.82 to 40.78 mJ/m2. The change in surface property was attributed to the laser-induced refinement of α- Mg and β- Mg 17 Al 12 phases and enrichment of Al in the microstructure.

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