New Types of Geo-Composite Materials for Anti-Filtration Systems

The article discusses the results of studies of new types of geocomposite materials used for anti-filtration and drainage purposes in hydraulic engineering and environmental protection construction. As the main elements, the presented geocomposite materials include various types of synthetic materials – bentonite mats and profiled geomembrane. A distinctive feature of these materials is the inclusion of additional elements of geotextile material or polymer geomembrane in their design, these elements are connected to the main element by thermal bonding. As a result, the combined geocomposite materials acquire new properties: they become more waterproof and durable. At the same time, waterproof materials are used for anti-filtration systems (as screens and coverings for canals, ponds, dams and various types of waste collectors), and previous material are used for drainage systems (as drainage in hydraulic and civil engineering). New types of geocomposite materials have improved properties on water resistance and water permeability (filtration coefficient), durability and strength.

PEMBUATAN KOMPOSIT ISOLATOR PANAS BERBAHAN SERAT KAPUK (CEIBA PENTANDRA) DAN POLIPROPILENA DENGAN METODE THERMAL BONDING

Komposit adalah suatu material yang terbentuk dari kombinasi dua material ataulebih melalui pencampuran yang tidak homogen, sehingga menghasilkan sebuah material dengan sifat baru yang berbeda dengan material pembentuknya. Perkembangan teknologi komposit saat ini tidak hanya mengkaji pada variasi struktur namun juga bahan baku yang lebih ramah lingkungan, salah satu bahan baku yang memiliki potensi besar adalah serat kapuk. Serat kapuk (ceiba pentandra) merupakan satu komoditi agrikultur yang tersedia dalam jumlah yang besar di Indonesia, Pada penelitian ini, serat kapuk digunakan bahan baku pembuatan insulator panas. Hal ini menjadi peluang untuk membuat produk dari pemanfaatan serat kapuk untuk meningkatkan harga jualnya. Serat kapuk digunakan sebagai penguat dan jaring polipropilena digunakan sebagai matriks. Pembuatan komposit dari kedua bahan ini dilakukan dengan menggunakan metode hot press. Komposit dibuat dengan 3 komposisi kapuk dan polipropilena yang berbeda yaitu 25:75, 20:80 dan 15:85. Proses produksi dilakukan melalui penekanan dengan alat thermal bondingpada suhu 100 0 C dan durasi 4 kali 30 detik. Komposit yang telah terbentuk melewati pengujian suhu panas dan dingin dengan alat bantu berupa sensor suhu. Berdasarkan hasil pengujian ketahanan suhu panas dan dingin, diketahui bahwa komposit dengan komposisi 25:75 memiliki kemampuan paling baik untuk mempertahankan suhu ruangan. Persentase serat kapuk pada komposit berbanding lurus terhadap ketebalan komposit serta kemampuan komposit mempertahankan suhu dalam ruangan panas dan dingin.

CuS/rGO-PEG Nanocomposites for Photothermal Bonding of PMMA-Based Plastic Lab-on-a-Chip

We developed copper sulfide (CuS)/reduced graphene oxide (rGO)-poly (ethylene glycol) (PEG) nanocomposites for photothermal bonding of a polymethyl methacrylate (PMMA)-based plastic lab-on-a-chip. The noncontact photothermal bonding of PMMA-based plastic labs-on-chip plays an important role in improving the stability and adhesion at a high-temperature as well as minimizing the solution leakage from microchannels when connecting two microfluidic devices. The CuS/rGO-PEG nanocomposites were used to bond a PMMA-based plastic lab-on-a-chip in a short time with a high photothermal effect by a near-infrared (NIR) laser irradiation. After the thermal bonding process, a gap was not generated in the PMMA-based plastic lab-on-a-chip due to the low viscosity and density of the CuS/rGO-PEG nanocomposites. We also evaluated the physical and mechanical properties after the thermal bonding process, showing that there was no solution leakage in PMMA-based plastic lab-on-a-chip during polymerase chain reaction (PCR) thermal cycles. Therefore, the CuS/rGO-PEG nanocomposite could be a potentially useful nanomaterial for non-contact photothermal bonding between the interfaces of plastic module lab-on-a-chip.

Modern evaluation methods thermal oxidative stability of reactive fuels in dynamic conditions and prospects for their development

The article discusses methods for assessing the thermal bonding stability (TOC) of jet fuels. The importance of determining this indicator for the design and operation of modern and advanced aircraft was noted. It is indicated that the methods used for assessing TOC are indirect, which limits their accuracy and reliability. The article gives the author's expert assessment of the correlation of the method indicators with the operational properties of fuels. Promising areas for the development of methods for measuring the amount of deposits include modern optical research methods: spectroscopic reflectometry, laser ellipsometry, as well as direct measurement of micro-amounts of deposits on control elements.