Organic Coatings with Low IR Emission

A series of methods were employed to assess the performances of advanced coating materials based on components that can modify the spectral parameters of the surfaces on which these materials are applied in order to obtain passive military camouflage. Powder materials with high infrared (IR) reflectance were used to obtain this type of coatings, which also ingrain in their structure a significant volume of air that allow limitation of the radiative heat transfer of the coated source. The components were embedded in a polyurethane matrix, which facilitated the coating process on different surfaces. The bicomponent polyurethane-based binder used within the different composition tested is transparent to incident IR radiation, has no organic solvents, is highly flexible and possesses remarkable physical, chemical and mechanical properties: high surface adhesion, high flexibility and resistance against a number of chemical agents and external factors with destructive effect. The efficiency of these composite materials was further demonstrated by analyzing the thermal images of different objects.

Syntheses, Magnetic, Spectral and Biological Studies on the Coordination Compounds of N-(2-Hydroxyphenyl)-C-(3′- Carboxy-2′-Hydroxyphenyl) Thiazolidin-4-One

A dry benzene solution of the Schiff base, N-(2-hydroxyphenyl)-3′-carboxy-2′- hydroxybenzylideneimine upon reacting with mercaptoacetic acid undergoes cyclization and forms N- (2-hydroxyphenyl)-C-(3′-carboxy-2′-hydroxyphenyl)thiazolidin-4-one, LH3 (I). A MeOH solution of I reacts with Ni(II) and UO2(VI) ions and forms the monomeric coordination compounds, [Ni(LH)(MeOH)3] and [UO2(LH)(MeOH)]. The coordination compounds have been characterized on the basis of elemental analyses, molar conductance, molecular weight, spectral (IR, reflectance) studies and magnetic susceptibility measurements. I behaves as a dibasic tridentate OOS donor ligand in these compounds. The compounds are non-electrolytes (M = 4.3-6.4 mho cm2 mol-1) in DMF. Octahedral structure for Ni(II) and UO2(VI) compounds are suggested. LH3 (I) and its complexes while testing with E.Coli. (Gram Negative) and S. Aureus (Gram positive) bacteria show antibacterial activities.

Immobilised nickel(II), dioxomolybdenum(VI) and dioxouranium(VI) complexes on polystyrene resin

New polystyrene supported mixed Schiff bases(PSCH 2 –LH 2 ) and their coordination compounds with nickel(II), dioxomolybdenum(VI), and dioxouranium(VI) have been synthesized. PSCH 2 –LH 2 have been synthesized by the reaction of chloromethylated polystyrene crosslinked with divinylbenzene(PSCH 2 –Cl) and the Schiff bases(LH 2 ) derived from 3-formylsalicylic acid, ethylenediamine or propylene diamine, and acetylacetone. The polystyrene-supported coordination compounds are of the types: PSCH 2 –LM(where M = Ni, MoO 2, UO 2 ). They have been synthesized by the reaction of PSCH 2 –LH 2 and the metal salt/metal coordination compounds in DMF. The coordination compounds have been characterized on the basis of elemental analyses, IR, reflectance, and magnetic susceptibility measurements. The shifts of the ν (C=N)(azomethine), ν (C–O)(phenolic) and ν (C–O)(enolic) stretches indicate the ONNO donor behavior of PSCH 2 –LH 2. The polystyrene-supported Ni(II) compound is square planar; MoO2 (VI) and UO2 (VI) compounds are octahedral and Zr(IV) compounds are pentagonal bipyramidal. The compounds, PSCH 2 –LM(where M = Ni, MoO 2, and UO 2 ) are diamagnetic.

Synthesizing and Characterizing the Hybrid Pigment Fe 0.7 Cr1.3 O3 With High NIR Reflectance for Sustainable Energy Saving Applications

Today, a growing number of the world population face a rise in the cost of living, especially an increase in energy costs. That is why Energy-saving has become a vital issue. In this regard, one of the remarkable ways to reduce energy consumption is using cool pigments; therefore, many kinds of research have been done to improve pigments' infrared reflection capability. In this paper, the role of particle morphology was investigated to boost the infrared reflection property of iron-chromium-based pigments. For this purpose, a series of inorganic pigments based on the Fe0.7Cr1.3O3 formula was prepared via a hydrothermal method. The particles' morphology was altered by using surfactants to improve the pigments' reflecting properties. The IR reflectance results proved that the flaky particles exhibit an enhanced IR reflection, which is significantly higher than in the spherical one. Furthermore, the results have revealed that silica coating leads to a meaningful improvement in the IR reflection property. It was found that the maximum near-infrared solar reflectance of the sample with 2.63% succinic acid surfactant and silica coating was 52.23% compared to that of Fe0.7Cr1.3O3, which was 25.36%.

Пороговый эффект деградации супергидрофобных покрытий, вызванный воздействием озона

It is shown that the use of nanosecond pulsed laser processing of an aluminum alloy makes it possible to obtain a coating with a multimodal roughness. The coating consists mainly of micro- and nanoparticles of aluminum oxide. Subsequent vapor deposition of the hydrophobic agent provides a coating with superhydrophobic properties. Infrared (IR) reflectance spectroscopy has been used to study the effect of ozone on the properties of a superhydrophobic coating fabricated on the surface of an aluminum alloy. At times of exposure to ozone (with a concentration of 50 mg/m3) not exceeding 250 min, the effect of degradation of the coating was practically indetectable, which is associated with self-recovery of the coating performance during the ozonation process. At longer times, exposure to ozone leads to irreversible degradation of the superhydrophobic coating, which is mainly due to the desorption of the hydrophobic part of the fluorooxysilane molecule upon rupture of bonds of the Si-C type, as well as the adsorption of ozone on the textured surface.