Effect of initial deposition behavior on properties of electroless Ni-P coating on ZK60 and ME20 magnesium alloys

The composition of magnesium alloys is greatly associated with initial deposition behavior of electroless Ni-P coatings.Thus,the initial deposition behavior of electroless Ni–P coatings on ZK60 and ME20 alloys was investigated.The results indicated that differences in the alloy compositions significantly influenced the initial deposition process and the adhesive strength,corrosion resistance,and crystal structure.The initial deposition of coatings on ZK60 and ME20 alloys preferentially occurred on the precipitates.The precipitates in ZK60 alloy had higher chemical activity after HF activation and controlled the initial deposition rate of the coating.The initial deposition rate of the coating on ME20 alloy mainly depended on the density of the Mg F2 film formed by HF activation rather than on the precipitates.Owing to differences in the initial deposition process,the coating on ZK60 alloy had higher adhesive strength and better corrosion resistance than that on ME20 alloy.The coatings on ZK60 and ME20 alloys mainly had crystalline structures,and the coating on ME20 alloy had also a slight microcrystalline structure.

Remote plasma enhanced cyclic etching of a cyclosiloxane polymer thin film

The continuous evolution of chip manufacturing demands the development of materials with ultra-low dielectric constants.With advantageous dielectric and mechanical properties,initiated chemical vapor deposited(iCVD)poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane)(pV3D3)emerges as a promising candidate.However,previous works have not explored etching for this cyclosiloxane polymer thin film,which is indispensable for potential applications to the back-end-of-line fabrication.Here,we developed an etching process utilizing O2/Ar remote plasma for cyclic removal of iCVD pV3D3 thin film at sub-nanometer scale.We employed in-situ quartz crystal microbalance to investigate the process parameters including the plasma power,plasma duration and O2 flow rate.X-ray photoelectron spectroscopy and cross-sectional microscopy reveal the formation of an oxidized skin layer during the etching process.This skin layer further substantiates an etching mechanism driven by surface oxidation and sputtering.Additionally,this oxidized skin layer leads to improved elastic modulus and hardness and acts as a barrier layer for protecting the bottom cyclosiloxane polymer from further oxidation.

Hydrophobic surface induced pro-metastatic cancer cells for in vitro extravasation models

In vitro vascularized cancer models utilizing microfluidics have emerged as a promising tool for mechanism study and drug screening.However,the lack of consideration and preparation methods for cancer cellular sources that are capable of adequately replicating the metastatic features of circulating tumor cells contributed to low relevancy with in vivo experimental results.Here,we show that the properties of cancer cellular sources have a considerable impact on the validity of the in vitro metastasis model.Notably,with a hydrophobic surface,we can create highly metastatic spheroids equipped with aggressive invasion,endothelium adhesion capabilities,and activated metabolic features.Combining these metastatic spheroids with the well-constructed microfluidic-based extravasation model,we validate that these metastatic spheroids exhibited a distinct extravasation response to epidermal growth factor(EGF)and normal human lung fibroblasts compared to the 2D cultured cancer cells,which is consistent with the previously reported results of in vivo experiments.Furthermore,the applicability of the developed model as a therapeutic screening platform for cancer extravasation is validated through profiling and inhibition of cytokines.We believe this model incorporating hydrophobic surface-cultured 3D cancer cells provides reliable experimental data in a clear and concise manner,bridging the gap between the conventional in vitro models and in vivo experiments.