Capped inhibitor-loaded halloysite nanoclay-based self-healing silica coatings for corrosion protection of mild steel

The effect of polymeric nanocapsule capping in benzotriazole encapsulated into halloysite nanoclay (HNTs) dispersed into hybrid silica coatings was investigated for corrosion protection of mild steel. Optimization of the amount of inhibitor-loaded halloysite nanotubes with and without capping in the coating sol was carried out. The prepared formulations were dip-coated on mild steel substrates using dip-coater and then cured at 130 °C for 1 h. Surface morphology and elemental analysis of the nanoclay were studied using scanning electron microscopy and energy dispersive X-ray spectroscopy. X-ray diffraction and Fourier Transform Infrared spectroscopy analyses were carried out to confirm the encapsulation and capping of the halloysite nanoclay. The anti-corrosion and autonomic-healing properties of bare and coated substrates in 3.5 wt% NaCl solution were studied using electrochemical impedance spectroscopy, potentiodynamic polarization measurements and scanning vibrating electrode technique for varying exposure times. The coatings generated from the capped inhibitor-loaded HNTs dispersed sol-gel matrix was seen to provide higher corrosion resistance when compared to uncapped HNT based silica coatings. Electrochemical studies carried out for capped inhibitor-loaded HNT based coatings have shown an increase in charge transfer resistance to 10⁸ Ω cm² from 10⁶ Ω cm² of uncapped inhibitor-loaded HNT based coatings.     

A Potent,Selective CBX2 Chromodomain Ligand and Its Cellular Activity During Prostate Cancer Neuroendocrine Differentiation

Polycomb group (PcG) proteins are epigenetic regulators that facilitate both embryonic development and cancer progression. PcG proteins form Polycomb repressive complexes 1 and 2 (PRC1 and PRC2). PRC2 trimethylates histone H3 lysine 27 (H3K27me3), a histone mark recognized by the N-terminal chromodomain (ChD) of the CBX subunit of canonical PRC1. There are five PcG CBX paralogs in humans. CBX2 in particular is upregulated in a variety of cancers, particularly in advanced prostate cancers. Using CBX2 inhibitors to understand and target CBX2 in prostate cancer is highly desirable; however, high structural similarity among the CBX ChDs has been challenging for developing selective CBX ChD inhibitors. Here, we utilize selections of focused DNA encoded libraries (DELs) for the discovery of a selective CBX2 chromodomain probe, SW2_152F. SW2_152F binds to CBX2 ChD with a K_d of 80 nM and displays 24-1000-fold selectivity for CBX2 ChD over other CBX paralogs in vitro. SW2_152F is cell permeable, selectively inhibits CBX2 chromatin binding in cells, and blocks neuroendocrine differentiation of prostate cancer cell lines in response to androgen deprivation.     

Improvement of corrosion protection of steel by incorporation of a new phosphonated fatty acid in a phosphorus-containing polymer coating obtained by UV curing

Six formulations containing diacrylate monomers (from 89 to 92.5% (w/w)) as well as a phosphonated methacrylate monomer (from 1 to 10% (w/w)) were prepared. All formulations were UV-cured and the corrosion performance of the resulting coatings applied onto a steel substrate was assessed by electrochemical impedance spectroscopy (EIS). It was first shown that the coatings containing phosphonic acid methacrylate (MAPC1(OH)₂) instead of methacrylate phosphonic dimethyl ester (MAPC1) presented higher corrosion protection related to the strong adhesive properties of phosphonic acid on the metal substrate. A minimum MAPC1(OH)₂ content of 2.5% was determined to provide the highest impedance values (best efficiency). Then, a new bio-based compound, i.e. phosphonic acid-bearing oleic acid (phosphonated fatty acid), was synthesized and added as an inhibitor to the formulations. In the presence of this compound, the corrosion protection was notably improved. The beneficial effect of phosphonated fatty acid was explained by its inhibitive action at the steel/coating interface and by the improvement of the barrier properties.     

空气阻止剂NM360和氯磺化聚乙烯的协同作用对轮胎气密层气密性的影响

在轮胎气密层中使用了空气阻止剂NM360和氯磺化聚乙烯作为增强气密层性能的新材料。当NM360和氯磺化聚乙烯单独使用时,对气密层的气密性能影响不大,但是二者同时使用时,气密层的气密性大幅上升18%。因此,NM360和氯磺化聚乙烯具有协同作用,二者的协同作用可以大大增加气密层的气密性能。     

氯离子与咪唑啉复配缓蚀剂的合成与应用

利用油酸和二乙烯三胺为原料合成咪唑啉季铵盐缓蚀剂后,在50℃、5%的盐酸介质中用静态失重法对咪唑啉季铵盐与阴离子表面活性剂和无机阴离子的研究,得到了一个与咪唑啉季铵盐有最佳复配效果的复配体,咪唑啉季铵盐与I-复配比为1:1(质量比)时,缓蚀剂的缓蚀效果最佳.在不同时间和不同温度下对复合型缓蚀剂的缓蚀效率进行了研究.结果表明,新型缓蚀剂对A3钢的缓蚀率达到99%以上,与单独用咪唑啉季铵盐相比,其缓蚀效率提高了0.7%左右.     

Fault-tolerant hybrid epoxy-silane coating for corrosion protection of magnesium alloy AZ31

In this work, a hybrid epoxy-silane coating was developed for corrosion protection of magnesium alloy AZ31. The average thickness of the film produced by dip-coating procedure was 14 μm. The adhesion strength of the epoxy-silane coating to the Mg substrate was evaluated by pull-off tests and was found to be higher than 16 MPa both in dry and wet conditions. The hybrid epoxy-silane coating showed high corrosion resistance both when intact and when punched through by a needle. The low frequency impedance of intact coating was higher than 1 GΩ cm² after one month of immersion in 3.5% NaCl solution. Both, artificially induced defects and corrosion sites that appeared on the metal surface did not propagate. Their passivation behavior, that we call fault-tolerance, was observed by EIS, SVET-SIET and SEM-EDS. It was ascribed to the good adhesion, high coating integrity and corrosion inhibiting effect provided by diethylenetriamine used as epoxy hardener.     

过氧化物/TAIC/阻聚剂交联体系在硅橡胶中的应用

研究了不同过氧化物/异氰尿酸三烯丙酯(TAIC)/阻聚剂交联体系在硅橡胶中的应用,对不同交联体系的硫化特性、物理性能、耐热老化性能和压缩永久变形性能进行了测试,并分别与抗焦烧型过氧化物交联剂进行了对比。结果表明:过氧化物/TAIC/阻聚剂交联体系交联的硅橡胶具有卓越的抗焦烧性能,其焦烧时间都优于参比的抗焦烧型过氧化物交联剂,同时,也都具有较好的耐热老化性能和压缩永久变形性能。     

Electrochemical and optical microscopy study of red pepper seed oil corrosion inhibition by self-assembled monolayers (SAM) on 304 SS

Corrosion inhibition by red pepper seed oil (capsicol) on 304 stainless steel (SS) was studied in 1 M HCl solutions. The oil was extracted from the seed of the red pepper (Capsicum annuum L.), which was cultivated in East Java, Indonesia. Electrochemical and optical microscopy techniques were used to observe the performance of the corrosion-inhibition process. The inhibition efficiency reached 92.32% for an immersion time in capsicol of 30 min at room temperature and decreased with temperature. This inhibition behavior by capsicol was also justified by comparing the pictures of the samples with and without the inhibitor after corroding for one week.     

Entwicklung und Validierung eines Kühlmittelsensors zur Bewertung der Korrosionsschutzwirkung

A sophisticated thermal management is one of the main subsystems that enables combustion engines with high power density. In this context the demands on coolants are also increasing. There has to be a certain level of corrosion protection to ensure the functionality of the cooling system. Hereafter the result of an electrochemical sensor development is presented. With the knowledge of analytical and electrochemical results a quick test for characterizing coolants corrosion protection has been developed and validated.     

Inhibitory effect of chloroform on fermentative hydrogen and methane production from lipid-extracted microalgae

To improve the sustainability of microalgae as a bioenergy feedstock, lipid-extracted microalgae (LEM) are often further treated by anaerobic digestion (AD). However, the residual chloroform used for extracting lipids as a solvent could inhibit this process, an aspect that has not been studied to date. In this study, the inhibitory effect of chloroform on H₂ and CH₄ production was investigated by performing batch tests. To prepare the feedstock, Chlorella vulgaris was ultrasonicated and the supernatant was discarded after centrifugation. In case of H₂ production, it was found that the H₂ yield fell to almost half that of the control (15.6 mL H₂/g COD_added) at 100 mg CHCl₃/L. The reason for the decrease of the H₂ yield with the increase of chloroform level was due to the change of metabolites from acetate and butyrate to lactate via a non-hydrogenic reaction. In comparison with H₂ production, a much more severe inhibitory effect of chloroform on CH₄ production was observed. The inhibitor concentration (IC_{30, 60, and 90}) on H₂ production was 138, 319, and 622 mg CHCl₃/L, respectively, while concentrations of 15, 37, and 86 mg CHCl₃/L were obtained on CH₄ production. When the chloroform concentration was ≥25 mg/L on CH₄ production, more than 2 g COD/L of organic acids remained, resulting in a decrease of CH₄ yield. These findings indicate that the residual chloroform in LEM should be seriously considered to prevent possible microbial inhibition when designing a process for additional energy recovery from microalgae via AD.