Stearic Acid/Layered Double Hydroxides Composite Thin Films Deposited by Combined Laser Techniques.

Ruxandra Birjega,Rodica Zăvoianu,Valentina Marascu,Andreea Matei,Maria Daniela Ionita,Maria Dinescu,Mihai Cosmin Corobea,Angela Vlad

doi:10.3390/molecules25184097

Abstract

We report on the investigation of stearic acid-layered double hydroxide (LDH) composite films, with controlled wettability capabilities, deposited by a combined pulsed laser deposition (PLD)-matrix-assisted pulsed laser evaporation (MAPLE) system. Two pulsed lasers working in IR or UV were used for experiments, allowing the use of proper deposition parameters (wavelength, laser fluence, repetition rate) for each organic and inorganic component material. We have studied the time stability and wettability properties of the films and we have seen that the morphology of the surface has a low effect on the wettability of the surfaces. The obtained composite films consist in stearic acid aggregates in LDH structure, exhibiting a shift to hydrophobicity after 36 months of storage.

Highlights

The miniaturization tendency related to the last decade of industrial development has led to an increased need for new materials, based on hybrid or composite complex structures, with combined properties that can be tailored
We have previously demonstrated that laser techniques can be employed for the deposition of layered double hydroxide (LDH) films or their derived mixed oxides [12,13,14,15], matrix-assisted pulsed laser evaporation (MAPLE), and pulsed laser deposition (PLD) offering the advantages of supplying adherent films with controlled thickness
We report on the employing standard pulsed laser deposition and matrix-assisted pulsed laser evaporation for the growth of the composite organic-inorganic layers

Summary

Introduction

The miniaturization tendency related to the last decade of industrial development has led to an increased need for new materials, based on hybrid or composite complex structures, with combined properties that can be tailored. Layered double hydroxides (LDHs), known as hydrotalcites or anionic clays, are a class of host-guest materials that can fulfill the demands listed above. They are defined by the formula [M2+ 1−x M3+ x (OH)2 ]x+ (An− )x/n ·mH2 O (1). The LDH property that makes them a very appealing material is the adsorption behavior, due to their high layer charge density, their anionic exchange capacity, and their swelling abilities [2]. A broad area of practical applications has been reported until now for layered double hydroxides such as anion exchangers, polymer stabilizers, anion scavengers, catalysts and catalyst supports, adsorbents, photoactive materials, and pharmaceutics [3]

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