**2.2.3 Dynamic diffusion of light with laser source (DLS)**

Using a Zeta Seizer MALVERN UK, the average diameter of submicron particles is determined in aqueous suspension ranging 3 nm ÷1 μm.

### **2.2.4 Thermal analyses**

132 Materials Science and Technology

The characteristics of MA-MMA maleic copolymers with hydrophobic comonomer and of

Characteristics MA-VA MA-MMA

Acid index 0.481 g NaOH/ g copolymer 0.2535 g NaOH/ g

acetate 1 : 0.77

Physical-chemical and structural properties of purified layered silicate, of binary nanocomposites based on layered silicate/maleic copolymers and of ternary nanocomposites of collagen/layered silicate/maleic copolymers are determined by using

X-ray diffraction technique is used to determine the basal spacing. Difractograms are recorded on automatic system using a DRON-20 difractometer, with a horizontal goniometer and a scintillation counter. We used as radiation source, CoK (λ = 1.7902 Å) filtered with Fe in order to remove kβ component from the Bragg-Brentano system (in

where *n* represents the reflexion order, *λ* is the wavelength of X-rays, *θ* is the diffraction angle, *d* is the distance between the planes of crystalline network which produces the

Nanocomposite particles shape and dimension are observed using a scanning electron microscope and microanalyzed with an energy dispersive X-ray spectrometer (EDAX). The

2sin 

96000 g/mole 49000 g/mole

copolymer

maleic anhydride : methyl methacrilate 1 : 2.17

(1)

MA-VA maleic copolymers with hydrophilic comonomer are presented in Table 1.

Composition maleic anhydride : vinyl

**2.2 Methods of physical-chemical and structural characterization** 

reflexion mode). *Basal spacing* is determined using Bragg equation1:

<sup>n</sup>λ = 2d sin θ, d = <sup>n</sup>

**2.2.2 Scanning electron microscopy (SEM)** 

Fig. 2. Chemical structure of MA-MMA copolymer.

Table 1. The characteristics of maleic copolymers.

different techniques described below.

**2.2.1 X-ray diffraction** 

diffraction.

Average viscosimetric molecular weight, Mw

Thermal behavior of the obtained materials is analyzed by determining the sample weight loss when heated at a constant rate (TGA), depending on temperature. By differential thermal analyses (DTA) we determine the temperature at which we get the highest decomposition rate. Thermal tests are performed on THERMAL ANALYST DUPONT 2100 using:


### **2.3 Biocompatibility**

Biocompatibility properties are evaluated on already obtained binary/ternary systems using *in vitro* tests. Biocomposite matrices are cut into small samples (1 cm2) and are sterilized in ultraviolete light on the both sides. The samples are sown with osteoblast cells from G 292 cellular line at an initially cellular density of 3.5 x 105 cells/plate. The obtained cultures are hatched at 37 °C in moist atmosphere with 5% CO2, then monitored from cytomorphologically point of view at 24 and 72 hours and from cellular viability point of view after 72 hours since hatching. After 24 hours, the matrices are observed under a Nikon TS 100 microscope in phase contrast and pictures are taken using a Nikon Cooplix 4500 digital camera. After 72 hours, the cultures are stained with hypericin and pictures are taken.
