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The purpose of this paper is to develop an optimised sonochemical surface modification process which could be operated at low temperature and which uses non‐hazardous chemistry with short treatment times. A range of sonochemical parameters such as ultrasonic intensity/power and process temperature were investigated.

A 20 kHz ultrasonic probe was used as the ultrasonic source. Ultrasound was applied through deionised water (DI) to sonochemically surface modify a high Tg epoxy laminate material (Isola 370 HR). The efficiency of the sonochemical surface modification process was determined by weight loss, roughness, adhesion and scanning electron microscopy (SEM).

This study has confirmed that ultrasound has the ability to surface modify a high Tg epoxy substrate material (Isola 370 HR). Weight loss and roughness values were increased by using an optimised ultrasonic process compared to control samples which were processed under “silent” conditions. Adhesion testing showed an improvement in the adhesion level between the surface and the subsequently electroless plated copper.

Surface modification of high Tg materials generally utilizes wet chemical methods. These processes involve using hazardous chemicals, high temperatures, require high volumes of water for rinsing and need relatively long immersion times. This research has shown that by optimising ultrasonic parameters, surface modification can be brought about in deionised water (DI) at low temperature.

This paper sets out to give an introduction to sonochemistry and the effects brought about by the application of ultrasound that might be useful in surface modification; and to show the feasibility of sonochemical surface modification in water on a range of materials employed in electronic manufacturing.

Ultrasound was applied through DI water for the surface modification of four materials: a ceramic, a polyphenylene ester (polystyrene polymer (Noryl HM4025)), an acrylonitrile‐butadiene‐styrene/polycarbonate (ABS/PC‐Cycolac S705), and an FR4 laminate (Isola Duraver 104). The efficacy of the treatment was determined by weight loss, scanning electronic microscopy, contact angle and roughness.

Ceramic and Noryl materials can be surface modified sonochemically in DI water. Weight loss results suggested that, this was also the case for the Duraver laminate but the ABS/PC substrate was least affected by treatment in an ultrasonic field under these benign processing conditions.

Traditional “wet” surface modification techniques often use hazardous chemistry, high‐process temperatures, copious rinsing and long dwell times. This research programme addresses these issues by evaluating sonochemical surface modification techniques with the objective of producing a one‐step process using benign chemistry at lower temperature with less rinsing.

To build on the results detailed in the previous paper where it was shown that sonochemical surface modification could be achieved in water. This paper aims to look at one of the factors affecting sonochemical surface modification, namely the ultrasonic source to sample distance.

Ultrasound was applied through deionized water for the surface modification of three materials: a high Tg PCB laminate (Isola 370HR), a polyphenylene ether – polystyrene polymer (Noryl HM4025) and an acrylonitrile‐butadiene‐styrene/polycarbonate (Cycolac S705). The efficacy of the treatment was determined by weight loss, scanning electron microscopy, contact angle, roughness and tape testing after electroless copper plating.

The study confirmed, and extended the previous findings, that a range of substrates could be sonochemically surface modified in water, even though in this work the ultrasonic horn had a larger tip size and produced a different ultrasonic intensity. Although the results were material dependent, the ultrasonic source to sample distance was found to be critical. Employing a spacing of 5 mm produced samples which generally exhibited higher weight loss, roughness and significant changes in surface morphology than when a distance of 25 mm was utilized.

The paper demonstrates that sonochemical surface modification has the potential to be a much more sustainable surface modification process than those currently employed in the electronics industry. However, to achieve this outcome acoustic cavitation and factors affecting it (such as source to sample distance) must be understood so that suitable equipment can be built.

Carbon dioxide (CO₂) has attracted special scientific interest over the last years mainly because of its relation to climate change and indoor air quality. Except for this, CO₂ can be used as an indicator of food freshness, patients’ clinical state and fire detection. Therefore, the accurate monitoring and controlling of CO₂ levels are imperative. The development of highly sensitive, selective and reliable sensors that can efficiently distinguish CO₂ in various conditions of temperature, humidity and other gases’ interference is the subject of intensive research with chemi-resistive zinc oxide (ZnO)-based sensors holding a privileged position. Several ZnO nanostructures have been used in sensing applications because of their versatile features. However, the deficient selectivity and long-term stability remain major concerns, especially when operating at room temperature. This study aims to encompass an extensive study of CO₂ chemi-resistive sensors based on ZnO, introducing the most significant advances of recent years and the best strategies for enhancing ZnO sensing properties.

An overview of the different ZnO nanostructures used for CO₂ sensing and their synthesis methods is presented, focusing on the parameters that highly affect the sensing mechanism and, thus, the performance of CO₂ sensors.

The selectivity and sensitivity of ZnO sensors can be enhanced by adjusting various parameters during their synthesis and by doping or treating ZnO with suitable materials.

This paper summarises the advances in the rapidly evolving field of CO₂ sensing by ZnO sensors and provides research directions for optimised sensors in the future.

Nowadays, the usage of antibacterial textiles is very popular for different type of textiles. The silver (Ag) and zinc oxide (ZnO) are the most popular materials in order to improve antibacterial properties of textiles. The purpose of this paper is to investigate the possibility to produce Ag nanoparticle (NP), ZnO NP, Ag/ZnO NP composite materials in this experimental study.

It was investigated whether it was possible to produce Ag NP, ZnO NP, Ag/ZnO NP composite materials by hydrothermal method which was known as in-situ approach on the fiber. In addition, the colloidal silver (Ag+) was produced by electrolysis method, and used instead of process water which was necessary during generating of NPs on the fiber by this method. After whole applications, the samples were characterized by SEM, XRD, EDX analyses and the antibacterial activity of specimens was tested according to the ASTM E 2149-01 (gram-negative Escherichia coli). In addition, the resistance to the repeated washes of these antibacterial samples was investigated.

The production of NPs on the fiber was achieved. The results showed that the samples had sufficient antibacterial activity and this activity did not reduce depending on repeated washing treatments.

Because of usage of one type of fiber, it would be necessary to make researches on the different type of fiber, testing procedure (with different bacteria), washing replications and prescriptions.

During the process the temperature control is very important for the produced fiber. In addition chosen antibacterial test method is crucial for the testing of activity of product. Fiber must be washed at least once to remove unfixed NPs on the fiber.

The technical antibacterial polyester fiber was in-situ coated by hydrothermal method with Ag, ZnO, Ag/ZnO composite NPs.

The main purpose of this study was to prepare the cotton fibers and cellulose powder by a layer of nano-crystalline-titanium dioxide (TiO₂) using the sol-gel sono-synthesis method to clean the wastewater containing reactive dye. Moreover, TiO₂ nano-materials are remarkable due to their photoactive properties and valuable applications in wastewater treatment.

In this research, TiO₂ was synthesized and deposited effectively on cotton fibers and cellulose powder using ultrasound-assisted coating. Further, tetra butyl titanate was used as a precursor to the synthesis of TiO₂ nanoparticles. Reactive dye (red 195) was used in this study. X-ray Diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy were performed to prove the aptitude for the formation of crystal TiO2 on the cotton fibers and cellulose powder along with TiO₂ nanoparticles as well as to analyze the chemical structure. Decoloration of the wastewater was investigated through ultraviolet (UV-Visible) light at 30 min.

The experimental results revealed that the decolorization was completed at 2.0 min with the cellulose nano TiO₂ treatment whereas cotton nano TiO₂ treated solution contained reactive dyestuffs even after the treatment of 2 min. This was the fastest method up to now than all reported methods for sustainable decolorization of wastewater by absorption. Furthermore, this study explored that the cellulose TiO₂ nano-composite was more effective than the cotton TiO₂ nano-composite of decoloration wastewater for the eco-friendly remedy.

Cotton fibers and cellulose powder with nano-TiO₂, and only reactive dye (red 195) were tested.

With reactive dye-containing wastewater, it seems to be easier to get rid of the dye than to retain it, especially from dyeing of yarn, fabric, apparel, and as well as other sectors where dyestuffs are used.

This research would help to reduce pollution in the environment as well as save energy and cost.

Decoloration of wastewater treatment is an essential new track with nano-crystalline TiO2 to fast and efficient cleaning of reactive dyes containing wastewater used as a raw material.

This study aims to investigate the interfacial microstructures of ultrasonic-assisted solder joints at different soldering times.

Solder joints with different microstructures are obtained by ultrasonic-assisted soldering. To analyze the effect of ultrasounds on Cu₆Sn₅ growth during the solid–liquid reaction stage, the interconnection heights of solder joints are increased from 30 to 50 μm.

Scallop-like Cu₆Sn₅ nucleate and grow along the Cu₆Sn₅/Cu₃Sn interface under the traditional soldering process. By comparison, some Cu₆Sn₅ are formed at Cu₆Sn₅/Cu₃Sn interface and some Cu₆Sn₅ are randomly distributed in Sn when ultrasonic-assisted soldering process is used. The reason for the formation of non-interfacial Cu₆Sn₅ has to do with the shock waves and micro-jets produced by ultrasonic treatment, which leads to separation of some Cu₆Sn₅ from the interfacial Cu₆Sn₅ to form non-interfacial Cu₆Sn₅. The local high pressure generated by the ultrasounds promotes the heterogeneous nucleation and growth of Cu₆Sn₅. Also, some branch-like Cu₃Sn formed at Cu₆Sn₅/Cu₃Sn interface render the interfacial Cu₃Sn in ultrasonic-assisted solder joints present a different morphology from the wave-like or planar-like Cu₃Sn in conventional soldering joints. Meanwhile, some non-interfacial Cu₃Sn are present in non-interfacial Cu₆Sn₅ due to reaction of Cu atoms in liquid Sn with non-interfacial Cu₆Sn₅ to form non-interfacial Cu₃Sn. Overall, full Cu₃Sn solder joints are obtained at ultrasonic times of 60 s.

The obtained microstructure evolutions of ultrasonic-assisted solder joints in this paper are different from those reported in previous studies. Based on these differences, the effects of ultrasounds on the formation of non-interfacial IMCs and growth of interfacial IMCs are systematically analyzed by comparing with the traditional soldering process.