Antimicrobial Agents for Textiles: Types, Mechanisms and Analysis Standards

The large surface area, and ability to retain moisture of textile structures enable microorganisms’ growth, which causes a range of undesirable effects, not only on the textile itself, but also on the user. Moreover, textiles used in health care environments are required to possess antimicrobial property to minimize spread of pathogenic infection. Anti-microbial property can be imparted via chemical finishing with an antimicrobial agent. Currently the use of antimicrobial agents includes metal compounds (notably copper and silver particle), chitosan, halogenated phenols “triclosan”, quaternary ammonium compounds, antibiotics (a class of antimicrobials produced from microorganisms that act against one another), and N-halamines. The possibility of bacterial resistance limits antibiotic use to specific medical applications, and triclosan is known for being dangerous to the environment and is currently under scrutiny for possible endocrine disrupting to human being. Although quaternary ammonium compounds are stable and easily manufactured, microbial resistance is also a concern. Quaternary ammonium compounds (QACs), Polyhexamethylene Biguanide (PHMB), chitosan and N-halamines are listed under bound or non-leaching type antimicrobials. The bulk of current chapter focuses on the different family of antimicrobial agents used for textiles and their mechanisms.

Interaction between Gelatin and Nano-Silver Particle: Foundation for Nano-Silver in Antibacterial Leather

In order to explain the interaction between collagen and nano-silver, gelatin solution was blended with nano-silver particles (AgNPs) with particle size 26 mm, and then the mixture was interacted under different time, pH and temperature. The changes in the process were measured by UV-Vis, fluorescence spectroscopy, dynamic light scattering and FT-IR. The results showed that the main type of reaction between gelatin and AgNPs was electrostatic interaction and the interaction was diffusive encounters. The particle size and distribution of nano-silver would not be affected by gelatin, however, there was dynamic fluorescence quenching of gelatin after nano-silver particle induced. The longer time and lower pH were beneficial for the interaction process while the interaction balanced after 60 min and pH 3.0 resulted in the most drastic interaction. Moreover, nano-silver would not impair gelatin structure during the interaction process. In short, the results in this work might be a foundation and reference for applying nano-silver in antibacterial leather producing.

Comparing low-temperature thermal and plasma sintering processes of a tailored silver particle-free ink

Silver particle-free inks are under rapid development due to their unique properties. Currently, most of the developed silver particle-free inks contain multiple components. In addition to the necessary solvents and silver precursors, these inks also contain complexing agents, reducing agents, and various additives. While such complex compositions assure good stability and printability of the inks, they hamper the sintering process as excess time and energy are often required to remove residues from various compositions to ensure high conductivities of the printed structures. Thus, a simple ink system is expected. On the other hand, plasma sintering shows its sintering potential in treating silver particle-free inks, but is only employed for the sintering of silver nitrate or silver acetate-based inks. Consequently, developing new particle-free ink systems with simple compositions and exploring the potential of plasma sintering is very meaningful. In this work, a clear and transparent silver particle-free ink was formulated, which can be treated both by low-pressure argon plasma sintering and low-temperature thermal sintering (120–160 °C). The roles of 2-amino-2-methyl-1-propanol (AMP) in the ink formulation were investigated in detail, which not only acts as the solvent but also as the complexing agent for silver oxalate to lower the sintering temperature of the ink. The electrical performance of the formulated ink was examined for both sintering processes for different conditions. The thermal sintering resulted in a resistivity value of 24.3 μΩ·cm on glass substrates after treatment at 160 °C for 60 min, while the plasma sintering yielded a resistivity value of 29 μΩ·cm at 500 W for 30 min. Compared to thermal sintering, plasma sintering achieved a similar electrical performance, but with a more nonuniform film structure. The power, sintering time, and the pressure of argon are key factors responsible for the conductivity of the produced films. Nevertheless, both resistivity values do meet the minimal electrical requirements of most electronic applications.

Uji Efikasi Nanoinsektisida Komposisi Perak Tembakau (Nicotiana tabacum) terhadap Aedes aegypti

Vector control that used insecticides need to be substituted, because it has a negative impact for the environment and have been resistance for some areas, so it was necessary to find alternative insecticides. One of the natural insecticides was tobacco (Nicotiana tabacum). The chemical content of tobacco leaves included alkaloids, saponins, and flavonoids. Nicotine was an alkaloid group compound in tobacco, thatwas a nerve poison that reacts quickly and can act as a contact poison in insects, to add the effectiveness it’s necessary change to nano particle with silver. Besides, this test used two solvents with different contains of mineral to compare the effectiveness. This study aimed to test effication of nanoinsecticide from formulation tobacco (Nicotiana tabacum) and silver particle for vector control of larvae Ae.aegypti. It was held at the Center for Research and Development of Disease Vector and Reservoir (B2P2VRP) with an experimental method. The results of the study showed 1,153 ppm LC50, 1,719 ppm LC90 and 1,925 ppm LC90 on solvent distilled water. LC50 of 1,641 ppm, LC90 of 10,741 ppm and LC90 of 18,295 ppm in solvent aquademineralization. Measurements of tobacco nanoinsecticides are known to be 89,2 – 112,0 run in aquadest and 89,2 -112,0 μm in aquademineralization solvents 79,0 – 143,7μm. Abstrak Pengendalian vektor menggunakan insektisida kimiawi perlu disubstisusi karena berdampak buruk pada lingkungan dan menyebabkan resistensi di beberapa daerah, sehingga perlu untuk mendapatkan insektisida alternatif yang ramah lingkungan. Salah satu tanaman insektisida alam, adalah tembakau (Nicotiana tabacum). Kandungan kimia tembakau meliputi alkaloid, saponin, dan flavanoid. Nikotin termasuk senyawa alkaloid dalam tembakau merupakan racun syaraf dengan reaksi cepat serta dapat berfungsi sebagai racun kontak serangga. Namun, untuk menambah daya bunuhnya sebagai larvasida maka ukuran partikel alkaloid perlu dipecah contohnya dengan penambahan perak. Pemilihan perak sebagai pembentuk molekul nano, sedangkan pelarut yang digunakan yaitu akuades dan akuademineralisasi. Kedua pelarut yang digunakan merupakan pelarut standar yang mempunyai daya kelarutan tinggi dengan perbedaan kandungan mineral. Penelitian ini bertujuan untuk uji efikasi nanoinsektisida tembakau (Nicotiana tabacum) yang diformulasikan dengan perak sebagai sarana pengendalian Aedes aegypti stadium pradewasa. Penelitian dilaksanakan di Balai Besar Penelitian dan Pengembangan Vektor dan Reservoir Penyakit (B2P2VRP) dengan metode eksperimental murni. Hasil penelitian didapatkan LC50 1,153 ppm, LC90 1,719 ppm pada pelarut akuademineraliasi dan LC90 1,925 ppm pada pelarut akuades. LC50 1,641 ppm, LC90 10,741 ppm dan LC90 18,295 ppm pada pelarut akuademineralisasi. Pengukuran partikel nanoinsektisida daun tembakau diketahui berukuran 89,2 - 112,0 nm pada pelarut akuades dan 89,2 -112,0 nm pada pelarut akuademineralisasi 79,0 - 143,7nm.