Electrolytically Ionized Abrasive-Free CMP (EAF-CMP) for Copper

Chemical–mechanical polishing (CMP) is a planarization process that utilizes chemical reactions and mechanical material removal using abrasive particles. With the increasing integration of semiconductor devices, the CMP process is gaining increasing importance in semiconductor manufacturing. Abrasive-free CMP (AF-CMP) uses chemical solutions that do not contain abrasive particles to reduce scratches and improve planarization capabilities. However, because AF-CMP does not use abrasive particles for mechanical material removal, the material removal rate (MRR) is lower than that of conventional CMP methods. In this study, we attempted to improve the material removal efficiency of AF-CMP using electrolytic ionization of a chemical solution (electrolytically ionized abrasive-free CMP; EAF-CMP). EAF-CMP had a higher MRR than AF-CMP, possibly due to the high chemical reactivity and mechanical material removal of the former. In EAF-CMP, the addition of hydrogen peroxide (H2O2) and citric acid increased the MRR, while the addition of benzotriazole (BTA) lowered this rate. The results highlight the need for studies on diverse chemical solutions and material removal mechanisms in the future.

β-Cyclodextrin-Based Nanosponges Functionalized with Drugs and Gold Nanoparticles

Drugs are widely used as therapeutic agents; however, they may present some limitations. To overcome some of the therapeutic disadvantages of drugs, the use of β-cyclodextrin-based nanosponges (βCDNS) constitutes a promising strategy. βCDNS are matrices that contain multiple hydrophobic cavities, increasing the loading capacity, association, and stability of the included drugs. On the other hand, gold nanoparticles (AuNPs) are also used as therapeutic and diagnostic agents due to their unique properties and high chemical reactivity. In this work, we developed a new nanomaterial based on βCDNS and two therapeutic agents, drugs and AuNPs. First, the drugs phenylethylamine (PhEA) and 2-amino-4-(4-chlorophenyl)-thiazole (AT) were loaded on βCDNS. Later, the βCDNS–drug supramolecular complexes were functionalized with AuNPs, forming the βCDNS–PhEA–AuNP and βCDNS–AT–AuNP systems. The success of the formation of βCDNS and the loading of PhEA, AT, and AuNPs was demonstrated using different characterization techniques. The loading capacities of PhEA and AT in βCDNS were 90% and 150%, respectively, which is eight times higher than that with native βCD. The functional groups SH and NH2 of the drugs remained exposed and allowed the stabilization of the AuNPs, 85% of which were immobilized. These unique systems can be versatile materials with an efficient loading capacity for potential applications in the transport of therapeutic agents.

Plasma and Aerosols: Challenges, Opportunities and Perspectives

The interaction of plasmas and liquid aerosols offers special advantages and opens new perspectives for plasma–liquid applications. The paper focuses on the key research challenges and potential of plasma-aerosol interaction at atmospheric pressure in several fields, outlining opportunities and benefits in terms of process tuning and throughputs. After a short overview of the recent achievements in plasma–liquid field, the possible application benefits from aerosol injection in combination with plasma discharge are listed and discussed. Since the nature of the chemicophysical plasma-droplet interactions is still unclear, a multidisciplinary approach is recommended to overcome the current lack of knowledge and to open the plasma communities to scientists from other fields, already active in biphasic systems diagnostic. In this perspective, a better understanding of the high chemical reactivity of gas–liquid reactions will bring new opportunities for plasma assisted in-situ and on-demand reactive species production and material processing.

Shape- and size-dependences of gold nanostructures on the electrooxidation of methanol under visible light irradiation

Plasmonic metal nanocatalysts have excellent light trapping properties and high chemical reactivity.

The importance of cylinder passivation for preparation and long-term stability of multicomponent monoterpene primary reference materials

Monoterpenes play an important role in atmospheric chemistry due to their large anthropogenic and biogenic emission sources and high chemical reactivity. As a consequence, measurements are required to assess how changes in emissions of monoterpenes impact air quality. Accurate and comparable measurements of monoterpenes in indoor and outdoor environments require gaseous primary reference materials (PRMs) that are traceable to the international system of units (SI). PRMs of monoterpenes are challenging to produce due to the high chemical reactivity and low vapour pressures of monoterpenes and also their propensity to convert into other compounds, including other terpenes. In this paper, the long-term stability of gravimetrically prepared static monoterpene PRMs produced in differently passivated cylinders, including sampling canisters, was assessed. We demonstrate that static PRMs of multiple monoterpenes can be prepared and used as a suitable long-term standard. For the first time the effect of cylinder pressure and decanting from one cylinder to another on the chemical composition and amount fraction of monoterpenes was also studied. Gravimetrically prepared PRMs of limonene in high pressure cylinders were compared to a novel portable dynamic reference gas generator based on dilution of pure limonene vapour emitted from a permeation tube.

The importance of cylinder passivation chemistry for preparation and long-term stability of multicomponent monoterpene primary reference materials

Monoterpenes play an important role in atmospheric chemistry due to their large anthropogenic and biogenic emission sources and high chemical reactivity. As a consequence, measurements are required to assess how changes in emissions of monoterpenes impact air quality. Accurate and comparable measurements of monoterpenes in indoor and outdoor environments require gaseous primary reference materials (PRMs) that are traceable to the international system of units (SI). PRMs of monoterpenes are challenging to produce due to the high chemical reactivity and low vapour pressures of monoterpenes and also their propensity to convert into other compounds, including other terpenes. In this paper, the long-term stability of gravimetrically prepared static monoterpene PRMs produced in differently passivated cylinders, including sampling canisters, was assessed. We demonstrate that static PRMs of multiple monoterpenes can be prepared and used as a suitable long-term standard. For the first time the effect of cylinder pressure and decanting from one cylinder to another on the chemical composition and amount fraction of monoterpenes was also studied. Gravimetrically prepared PRMs of limonene in high pressure cylinders were compared to a novel portable dynamic reference gas generator based on dilution of pure limonene vapour emitted from a permeation tube.

Management of Maceration-Fermentation Technologies Regarding the Antioxidant Profiles of Some Wines from Iasi Vineyard

The vine contains, in addition to sugars and acids, important amounts of phenolic compounds that accumulate in the solid parts of grapes (clusters, seeds) and skin. The quantity and quality of phenol compounds depends on both the plant and the technology of grape processing. Their high chemical reactivity makes them participate in chemical processes, especially oxido-reduction and condensation. At the same time, these substances have antioxidant qualities that delay the oxidation of wine components. Phenolic compounds also have interesting biological properties. Recent medical research attributed to phenolic compounds from grapes, juice and wines, especially red ones, remarkable sanogenic qualities, due in particular to their antioxidant action when it comes to polyphenols, cardiovascular protection, antiviral, antihistaminic, anti-cancer, anti-inflammatory, etc.This study analyses the management of various maceration-fermentation processes and their influence on the antioxidant capacity of some wines from Iasi vineyard, but also their correlation with specific phenol compounds. The management of winemaking technologies can produce wines with high antioxidant potential, a plus for an increasingly demanding consumer.

Parametric Optimization of Machining Ti-Alloys in Respect to Surface Roughness - A Review

The uses of Titanium alloys have largely been increased due to the benefits which are very substantial in some specific areas. Their applications are not only limited to in aerospace industries and biomedical implants but also widely introduced in marine and automotive industries. Yet the optimum cutting conditions for those materials are still under investigation. Ti-alloys are in the group of difficult-to-machine materials due to their poor machinability. The main reasons behind their poor machinability are high chemical reactivity, low modulus of elasticity and low thermal conductivity. Here in this paper a number of literatures related to optimization of machining parameters are reviewed and the problems related to machining of these Ti-alloys including their effects are summarized.