Organic–inorganic hybrid materials do not represent only a creative alternative to design new materials and compounds for academic research, but their improved or unusual features allow the development of innovative industrial applications. Nowadays, most of the hybrid materials that have already entered the market are synthesised and processed by using conventional soft chemistry based routes developed in the eighties. These processes are based on: a) the copolymerisation of functional organosilanes, macromonomers, and metal alkoxides, b) the encapsulation of organic components within sol–gel derived silica or metallic oxides, c) the organic functionalisation of nanofillers, nanoclays or other compounds with lamellar structures, etc. The chemical strategies (self-assembly, nanobuilding block approaches, hybrid MOF (Metal Organic Frameworks), integrative synthesis, coupled processes, bio-inspired strategies, etc.) offered nowadays by academic research allow, through an intelligent tuned coding, the development of a new vectorial chemistry, able to direct the assembling of a large variety of structurally well defined nano-objects into complex hybrid architectures hierarchically organised in terms of structure and functions. Looking to the future, there is no doubt that these new generations of hybrid materials, born from the very fruitful activities in this research field, will open a land of promising applications in many areas: optics, electronics, ionics, mechanics, energy, environment, biology, medicine for example as membranes and separation devices, functional smart coatings, fuel and solar cells, catalysts, sensors, etc.

Applications of hybrid organic–inorganic nanocomposites

Today cross-cutting approaches, where molecular engineering and clever processing are synergistically coupled, allow the chemist to tailor complex hybrid systems of various shapes with perfect mastery at different size scales, composition, functionality, and morphology. Hybrid materials with organic–inorganic or bio–inorganic character represent not only a new field of basic research but also, via their remarkable new properties and multifunctional nature, hybrids offer prospects for many new applications in extremely diverse fields. The description and discussion of the major applications of hybrid inorganic–organic (or biologic) materials are the major topic of this critical review. Indeed, today the very large set of accessible hybrid materials span a wide spectrum of properties which yield the emergence of innovative industrial applications in various domains such as optics, micro-electronics, transportation, health, energy, housing, and the environment among others (526 references).

Applications of advanced hybrid organic–inorganic nanomaterials: from laboratory to market

Layered double hydroxides (LDHs) have been investigated for many years as host materials for a range of anion exchange intercalation reactions. In this role they have been used extensively as ion-exchange materials, catalysts, sorbents and halogen absorbers. More recently, there have been a tremendous number of new developments using these materials to store and deliver biologically active materials in vivo. Significant advances have been made recently on the characterisation of these materials, including structural studies and on the mechanism of intercalation using in situ techniques.

Intercalation chemistry of layered double hydroxides: recent developments and applications

Perspectives for nano-biotechnology enabled protection and nutrition of plants

Clay minerals and layered double hydroxides for novel biological applications

Hybrid derivatives of layered double hydroxides

A new hybrid material with the composition [Zn1.9Al(OH)5.8][Cl2C6H3OCH2CO2·2.83H2O] has been synthesised via ion exchange of chloride by ions of a molecule belonging to the pesticide family, 2,4-dichlorophenoxyacetate (2,4D). The ion exchange in the zinc–aluminium–chloride layered double hydroxide, [Zn–Al–Cl], was investigated by X-ray diffraction and infrared spectroscopy. The effects of the anion concentration in solution, the 2,4D/[Zn–Al–Cl] molar ratio, the ageing time and the temperature on the ion exchange were studied. The best sample, in terms of crystallinity and extent of ion exchange, was obtained at 100 °C in a 0.004 M 2,4D solution in which the 2,4D/[Zn–Al–Cl] molar ratio was equal to 11, with 24 h of stirring time. This hybrid material was further characterised by chemical analyses and its thermal behaviour was also studied.

Preparation of a new stable hybrid material by chloride–2,4-dichlorophenoxyacetate ion exchange into the zinc–aluminium–chloride layered double hydroxide

Intercalation of metallic oxalato complexes CoOx22-, CuOx22-, MnOx33-, and GaOx33- in [Zn2Al] and [Mg2Al] LDHs was successfully carried out leading to well characterized products in which metallic ...

Preparation and Characterization of Intercalation Compounds of Layered Double Hydroxides with Metallic Oxalato Complexes

Reaction of oxalate anion with ZnAl layered double hydroxides (LDHs) gives rise to new LDH phases where either oxalate or aluminum oxalato complexes are intercalated depending on the exchange reaction conditions. Chemical characteristics, structural and spectroscopic data are presented.

Reactivity of oxalate with ZnAl layered double hydroxides through new materials

The Rietveld method, extended by a Fourier analysis of line profiles
on the basis of the Warren–Averbach method, has been used for analysing
the powder X-ray diffraction (PXRD) pattern of a [Zn–Al–Cl]
layered double hydroxide, in order to separate size and strain effects. Assuming
a given size distribution (Cauchy) and an adjustable strain variation in space,
this method allows the simultaneous determination of structural parameters
and the size and strain parameters of the sample. The shape, size, size distribution
and orientation of the crystallites are determined. It is found that the shape
is markedly anisotropic and compatible with plate-like crystallites with
a hexagonal symmetry; the structure being described in the Rm
space group. The strain parameter, i.e. the distribution of atomic
positions around their equilibrium positions, varies by a factor of 2 while
the mean particle size changes from 120 A to 2200 A
in the [001] and [110] directions, respectively. Such shape and size are in
good agreement with the transmission electron microscopy (TEM) observations.

Jean Pierre Besse

Papers

Hybrid derivatives of layered double hydroxides

Preparation of a new stable hybrid material by chloride–2,4-dichlorophenoxyacetate ion exchange into the zinc–aluminium–chloride layered double hydroxide

Preparation and Characterization of Intercalation Compounds of Layered Double Hydroxides with Metallic Oxalato Complexes

Reactivity of oxalate with ZnAl layered double hydroxides through new materials

Shape and size determination for zinc-aluminium-chloride layered double hydroxide crystallites by analysis of X-ray diffraction line broadening