Multilayer Critical properties

Figure 34 shows the critical load of all the samples. For the monolayer samples, Sample 1 has a higher critical load than Sample 2. The multilayers Samples 4, 5, and 6 have higher critical loads than monolayer Samples 1 and 2. Samples 5 and 6 have excellent scratch resistant properties. Only extremely small cracks are found in the scratch tracks of Samples 5 and 6. Therefore, there is no sudden change found in the force and penetration depth curves. Sample 7 has the lowest critical load, similar to the monolayer Sample 2. 

Hard layer and soft layer combined together can reduce the intrinsic stress of the whole coating [17,18,22-27]. Samples 4, 5, and 6 have higher critical load than that of monolayer A and B. For Samples 5 and 6, no obvious crack occurs during the scratch test. Sample 5 has the highest hardness and reduced elastic modulus among the multilayer samples, and the interfaces in Sample 5 also contribute to scratch resistance. So it has the best micromechanical properties here. 

The critical cracking load of Sample 7 is at almost the same level as that of Sample 2. This is because Samples 7 and 2 were made in Zone B and have similar properties. However, there is a difference from cracks between Samples 2 and 7 (refer to Fig. 35). This is mainly due to the fact that Sample 7 is a multilayer structure. 

The mechanical properties of polyelectrolyte multilayer capsules have been subject of several studies using different methods. Baumler and co-workers [7] have used the micropipette technique and found that PMCs are not conserving their volume if pressure differences are applied between inside and outside of the shell. This is expected, since the shells can only be formed in first place because the membrane is permeable to low molecular weight species, the core dissolution products. They found no deformation up to a critical pressure followed by an irreversible collapse, showing that shells deform not elastically but plastically for large deformations. First quantitative estimates of the Young s modulus of the shell material were obtained by Gao and coworkers, using osmotic pressure differences between inside and outside of the shell [8,9], These authors monitored the onset of the buck-... 

The technique of interspersing a layer with thin layers that eliminate pinhole formation can be applied to other systems as well. The method is, for example, successful in ST0/PrBa2Cu30y multilayers [14.70]. A layer-by-layer growth mode favors high quality multilayers with large critical thicknesses. The multilayer technique also opens possibilities to continuously vary the physical properties of the intermediate layers by combining two materials with different behaviors. 

Important processes in the carbon cycling system always happen in the air-sea interface (Fig. 3.10). As a result, it is critical in studying the multilayer distribution of CO2 system across the air-sea interface. In recent years, scientists have made a series of advances in studying the carbon biogeochemical process across the air-sea interface and its physical-chemical properties determinations. 

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