کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
590677 1453545 2015 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Surface microstructure of bitumen characterized by atomic force microscopy
ترجمه فارسی عنوان
ریزساختار سطح قیر مشخص شده توسط میکروسکوپ نیروی اتمی
کلمات کلیدی
قیر طبیعی پیوند آسفالت، میکروسکوپ نیروی اتمی، ریزپردازنده سطحی، زنبورها ساختارها، موم
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
چکیده انگلیسی


• A general picture of the diverse surface microstructures of bitumen is provided.
• Explanations about the chemical origin of ‘bee-structures’ are summarized.
• Technical challenges on AFM characterization of bitumen morphology are identified.
• Future work for chemical and microscopic mechanical characterization is discussed.

Bitumen, also called asphalt binder, plays important roles in many industrial applications. It is used as the primary binding agent in asphalt concrete, as a key component in damping systems such as rubber, and as an indispensable additive in paint and ink. Consisting of a large number of hydrocarbons of different sizes and polarities, together with heteroatoms and traces of metals, bitumen displays rich surface microstructures that affect its rheological properties. This paper reviews the current understanding of bitumen's surface microstructures characterized by Atomic Force Microscopy (AFM). Microstructures of bitumen develop to different forms depending on crude oil source, thermal history, and sample preparation method. While some bitumens display surface microstructures with fine domains, flake-like domains, and dendrite structuring, ‘bee-structures’ with wavy patterns several micrometers in diameter and tens of nanometers in height are commonly seen in other binders. Controversy exists regarding the chemical origin of the ‘bee-structures’, which has been related to the asphaltene fraction, the metal content, or the crystallizing waxes in bitumen. The rich chemistry of bitumen can result in complicated intermolecular associations such as coprecipitation of wax and metalloporphyrins in asphaltenes. Therefore, it is the molecular interactions among the different chemical components in bitumen, rather than a single chemical fraction, that are responsible for the evolution of bitumen's diverse microstructures, including the ‘bee-structures’. Mechanisms such as curvature elasticity and surface wrinkling that explain the rippled structures observed in polymer crystals might be responsible for the formation of ‘bee-structures’ in bitumen. Despite the progress made on morphological characterization of bitumen using AFM, the fundamental question whether the microstructures observed on bitumen surfaces represent its bulk structure remains to be addressed. In addition, critical technical challenges associated with AFM characterization of bitumen surface structures are discussed, with possible solutions recommended. For future work, combining AFM with other chemical analysis tools that can generate comparable high resolution to AFM would provide an avenue to linking bitumen's chemistry to its microscopic morphological and mechanical properties and consequently benefit the efforts of developing structure-related models for bituminous materials across the different length scales.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Advances in Colloid and Interface Science - Volume 218, April 2015, Pages 17–33
نویسندگان
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