Investigation And Explore The Physical And Chemical Properties Of Nanomaterial

The research of nanomaterials has become a hot field, and has become a hot field of scientificresearch,which involves physics, chemistry, biology and other disciplines. Due to nanomaterials haveunique optic, mechanical, electromagnetic properties, and thus has a wide range of applications in variousareas,which include our lives, learning, work, etc. the molecular self-assembly technique has been widelyused in the field of nano-technology. In this paper, we used polysaccharides, stearic acid andoctadecylamine as our research object, and explore the impact of temperature, pH, hydrophobic strength ofsubstrate and physical changes outside on molecular self-assembly, namely by through the perspective ofphysical and chemical factors.Polysaccharides, especially the study of polysaccharides films, has been applied in various fields, suchas biomedicine, biology and so on, xanthan of negatively charged and chitosan of positive charged are twokinds of representative polysaccharides. As xanthan gum have excellent physical and chemical properties inthe water-soluble polymer. It is often used as a research system with zwitterionic surfactants, and used themin the daily chemical industries, food industries, petroleum industry and textile industrial and ceramic andenamel industries. Research shows that xanthan gum molecule in aqueous solution are easy to formnetwork structure of multiple, and also film-like structure when increasing the concentration. Chitosan isonly one of positive charged polysaccharide in natural polysaccharide, and can be dissolved into the gel atmost weakly acidic conditions, thereby forming film structure. Because chitosan film with goodbiocompatibility, biodegradability, strong plasticity, and can control binding and releasing of drug andcarrier by changing the properties of film, such as changing the degree of swelling and diffusion, thuschitosan has been widely applied. The film-forming properties of xanthan and chitosan have been thestuding target for their valuable applications. In recent years, the balance between the hydrophobic andionic interactions has been exploited by using amphiphilic polysaccharide (palmitoyl xanthan), where thepalmitoyl xanthan was assembled into capsules in saline solutions. Moreover, the obvious differences ofmolecular heights on the different substrates have been exploited by dropping single molecule (single DNAmolecule and single xanthan molecule) on the different substrates. In summary, the balance between thehydrophobic and ionic interactions and the changing of single molecule’s height on the different substrates have been exploited, but the effect that substrates with different electrical property and differenthydrophobic properties on the compact degree of porous film of polysaccharides with different electricalproperty have not been exploited. In this article, we studied the effect of substrate’s hydrophobicity on thecompact degree of polysaccharide film by dropping two kinds of molecules with different electricalproperties(xanthan carries negatively charges and chitosan carries positively charges) onto the substrateswith different charges and different hydrophobic properties, although People have studied the morphologyof DNA on the hydrophobic substrates, and found that inevitably appeared the following situation: First,aggregation of DNA invariably occurs during drying process, leading to the formation of dense aggregatesof structurally indistinct material around the edge of the droplet. Second, materials which are notaggregated are distributed sparsely across the substrate, collecting in cracks and against step edge, we havedone a majority of experiment, aim to exploring the effect of different substrates’s different hydrophobicityto the compact degree of polysaccharide film.Because with the LB technique can accurately control the thickness and the uniformity of film, whichis superior to the conventional film-forming technique, and control arranged direction and organization ofthe molecular. We studied stearic acid and stearylamine by LB technique. Stearic acid is an importantcomponent of living body, and octadecylamine have an amino, thus often modified material by it, mainly tochange charged property and hydrophilicity of other material, the study of octadecylamine is used to pavethe way for scientific research in the future.In our study, we find that the hydrophobic strength of substrate plays an important role in theself-assembly progress, whether the substance carries positively charged and negatively charged. Somefactors include that the surface pressure, the concentration of the salt solution, the immersion time in thesalt solution, pH range, cationic strength of the salt solution plays an important role with the finalmorphology.