Click chemistry is widely used in materials and surface science for its high efficiency, ease of use and high yields. Azide-terminated SAMs have been prepared successfully by using three different deposition methods (postfunctionalization and direct grafting by immersion as well as spin coating). Strikingly, our study shows that the reactivity of the azido group on the surface with the alkyne in solution is not trivial and seems to be closely related to the orientation of the azide. Indeed, more the azide is vertically oriented more it is accessible and reactive. The orientation of azido dipoles at the surface depends strongly on the method used to prepare the monolayer. The post-functionalization method allows to have a homogeneous population of the azide groups on the surface with a better vertical orientation than that obtained using direct grafting by immersion or spin coating processes. Whatever the type of azide-terminated SAMs, the reactivity of the accessible vertical azido groups is complete. This study clearly demonstrates that it is possible to control the amount of reactive azides and, consequently, the amount of molecules immobilized on the surface after the click reaction by choosing the deposition method.

In the present work cellulose powder was extracted from olive industry solid waste and then converted into cellulose acetate. The cellulose powder was extracted from olive industry solid waste by kraft pulping process and multistep bleaching p sequences. An elemental chlorine-free chemical bleaching sequence chlorine dioxide (D)-cold caustic extraction (E)-hypochlorite (H)hydrogen peroxide (P) was used. Cellulose powder was obtained in about 35 % yield. The extracted cellulose and cellulose acetate made from thereof were extensively characterized using Fourier transform infrared spectroscopy, electron microscopy sciences, gel-permeation chromatography/high-performance liquid chromatography, and viscometry. Our key finding in this study was that olive industry solid waste is a valuable source of cellulose powder and its derivatives. This is important, since our results show how lignocellulosic agricultural wastes could be utilized and converted into cellulose products with high value.

Functionalization of silica surfaces with silane-based self-assembled monolayers (SAMs) is widely used in material sciences to tune surface properties and introduce terminal functional groups enabling subsequent chemical surface reactions and immobilization of (bio)­molecules. Here, we report on the synthesis of four organotrimethoxysilanes with various molecular structures and we compare their grafting by spin coating with the one performed by the conventional solution immersion method. Strikingly, this study clearly demonstrates that the spin coating technique is a versatile, fast, and more convenient alternative process to prepare robust, smooth, and homogeneous SAMs with similar properties and quality as those deposited via immersion. SAMs were characterized by PM-IRRAS, AFM, and wettability measurements. SAMs can undergo several chemical surface modifications, and the reactivity of amine-terminated SAM was confirmed by PM-IRRAS and fluorescence measurements.