Synthesis And Properties Of Organic Small Molecule Phase Change Materials

Molecular phase transformer materials have very important applications in the fields of sensors,optical sensors,so molecular phase change materials have become a major area of??research,and they are more challenging in terms of research on their performance.With the continuous improvement of phase-changing materials,researchers have designed synthetic new materials through chemical means,so that they are small in various fields to wearable equipment,flexible B-ultrasound,and larger applications as large as aerospace.In addition,relatively inorganic molecular iron electrical materials,organic small molecular iron electric materials have natural flexibility,and its synthesis process is simple,low-cost,and also has the advantages of lightweight non-toxic.Therefore,in the past ten years Related research has risen sharply.Based on the composition structure,the phase transformer material of organic small molecules can be divided into a single-group molecular system and an organic salt system.A single-group molecular phase change material and organic salt phase change material are typical molecular base materials.We designed the molecular structure based on the three molecular design strategies of iron electrical chemistry and ball-like-non-ball theory,the introduction of single-handedness and"dynamic matching"principles.Due to the superiority of organic small molecules,we have carried out a series of research on their synthesis and nature.In this article,we mainly applies to the construction strategy,ball-like theory,and hand-controlled regulation of the construction strategy of building potential single-group OMPTM for designing eight compounds.The eight compounds are:A A.Ridamine（1）,trivial acetram sulfonic acid（2）,1-sulfenyl-1-methylpyle（3）,1-sulfenyl-4-diopyramine（4）,diamond allec Sulfate（5）,pyrazine sulfate（6）,S-trimetroxy-N,N-dimethyl pyric（7）and R-trimetroxy-N,n-di metaphrile（8）.We carried out testing and inquiries of single-crystal structure,differential scanning heat meter,dielectric measurement,thermal weight,infrared spectrum,and X-ray powder diffraction meter.In Chapter Ⅲ,we used the construction strategy of building a potential single-group OMPTM to synthesize compounds 1,2,3,and 4.The test results show that compounds 1 and 3 have not changed,and the transformed compounds 2 and 4 after the transformation on it have occurred.Specifically,a pair of heat outer outer and hot peaks are found near 345 k（T_c）through DSC and dielectric testing.In the process of rising temperatures and lowering temperatures,compounds 4 appeared two pairs of heat-off and hot peaks,and near 286/278（T₁）and 302/311（T₂）.In addition,we found that the results of the compound 2 and 4 dielectric responses were corresponding to the results of the DSC test.It shows that there is a pair of reversible phase changes in compounds 2,and the compound 4 has two pairs of reversible phase changes.In Chapter Ⅳ,we imitate the ball-like-non-ball theory,synthetic compounds 5and 6.It was found that a pair of heat outer peaks and thermal peaks were existed at about 513 k（T_c）,which were at about 513 k（T_c）,and at 513K and 500 k,indicating that the phase change of 5 was reversible.The compound 6 occurs at about 376 k（T_c）,and appears in the 376k and 362 K respectively,indicating that the phase change of 6 is reversible.In addition,we found that compounds 5 and 6 in the process of rising temperatures and lowering temperatures are consistent with DSC tests.The above indicates that compounds 5 and 6 may have structural phase changes.In Chapter Ⅴ,we introduced hand-in-law regulation to successfully des ign compound 7 and 8.Through the differential scanning heat（DSC）and die lectric measurement,it is found that these two compounds appear a pair of h ot-absorbing peaks and hot peaks near 410K,and there is a very obvious st ep-type dielectric abnormalities.In addition,the analysis of the conjugated X-ray single crystal structure analysis from the normal temperature of the com pound showed that at the 293K time and space group P2₁2₁2₁.And there is a pair of reversible SHG phase changes,from a strong signal to no signal,in dicating that there is a change in the space group in the compound and from the asymmetric center to the symmetrical center.It can be seen that compou nds 7 and 8 have reversed phase changes.