Bitumen@SiO2 core-shell particles green synthesis towards flowable powdered bitumen and their binder applications

Abstract

Mineralization of flocculated bitumen emulsions allows producing bitumen powders, also referred to as Bitumen@SiO2 hybrid particles, that can resist storage in hard conditions, with a load up to 8 kPa at 50 °C during 20 hours, without alteration of their morphology or release of their bitumen core. Thanks to the flocculation, final Bitumen@SiO2 powders are not highly pulverulent and allow transportation and handling of bitumen at ambient temperature without the need of water as it is the case for bitumen emulsions. This "water free" storage particularity exhibits the double advantage of reducing the cost of transport and of avoiding inhibition of bitumen adhesion at mineral aggregates through the presence of water, therefore rendering the bitumen its high quality of binder. The silica shell is responsible for the high storage stability and, when mixed with aggregates for end use of asphalt, as for example in pavement applications, serves as mineral charge to the bitumen, modifying the bitumen flow properties. Indeed, when heated at 100°C and crushed, the capsules break releasing thus the bitumen. This suspension made of bitumen and silica shell fragments exhibits an interesting

Cross-linking of double oil-in-water-in-oil emulsions: A new way for fragrance encapsulation with tunable sustained release

“…Alternatively, the pressure could be released and the liquid remaining outside analyzed by GC ( Figure 20 The comparison of the proposed capsules with all the existing ones without focus on the goal and application is just an impossible task in the frame of an original paper. Therefore, the ambitious of this paragraph is limited to a comparison with some recent and novel systems [19,20,23,39,40,[52][53][54][55][56][57][58][59][60][61][62][63]] that aims at reducing or avoiding the use of formaldehyde, most of them being core-shell capsules. Also depending on the considered application, either a provoked sudden release of the cargo is aimed at [19,20,[54][55][56][60][61][62] or, on the contrary, a slow and sustained released is preferred or observed as it was the goal herein [39,40,52].…”

“…Pickering emulsions that is to say emulsions stabilized by particles are known to be very stable kinetically. In order to improve their tightness or mechanical properties the emulsion surface may be reinforce either by polymers that serve as a mortar [55], by polymerization at the interface [57] or by in-situ synthesis of a silica shell [19,20,54,[60][61][62][63][64][65].…”

“…The encapsulation of highly viscous bitumen recently led to powdered bitumen exhibiting the advantages of being flowable at room temperature, easily transportable, storable… [19,20] First fragrance encapsulation techniques have been developed [21] in the 70s with the aim to control the duration of fragrance release and to protect the fragrance from the environment.…”

Durability of bitumen binder reinforced with polymer additives: Towards upgrading Nigerian local bitumen

“…To cause bitumen flow requiring an activation energy between 50 and 120 kJ/mol. To attain a viscosity in the range between 1 and 10 Pa s requires heating the bitumen a temperature in the range of 120 and 190 °C [ 6 ]. Also, to achieve a fairly uniform dispersion of polymer in the bitumen matrix during the synthesis of polymer-modified bitumen (PMB), high temperatures and high shear rates are thus necessary, particularly when the polymer is crystalline and has a high melting point.…”

Efficient (Bio)emulsification/Degradation of Crude Oil Using Cellulose Nanocrystals

“…At the moment, the problems arising in connection with the formation of emulsions in oil-containing systems are mainly related to the separation of water from crude oil [17]. The authors of [17][18][19][20][21] point out that in such cases, this activity is complicated due to the presence of natural emulsifiers (fatty acids, asphaltenes), as well as highly dispersed mineral particles (argillites, quartz etc.) capable of generating their own Pickering emulsions [22].…”