An environment friendly technique for green synthesis of silver nanoparticles has been reported. Silver nanoparticle have been synthesized using water extract of leaves of pucuk idat (Cratoxylum glaucum), commonly known as local Bangka plant. The flavonoid and tannin present in the extract act as reducing agent. AgNO3 0,05 M solution was reducing using the extract at room temperature by stirring. Color changing of the solution was detected at 30 minutes reaction time. The color tends to be darker by the increasing of reaction time. Various techniques used to characterize synthesized nanoparticles are UV-Visible spectrophotometer, x-ray diffraction (XRD) and scanning electron microscopy (SEM). UV-Visible spectrophotometer showed absorbance peak in 405 nm, the XRD shows that silver nanoparticles formed are crystalline. The average particle size of Ag nanoparticles estimated from the Scherrer formula is 35,59 nm, while SEM image shows shape of silver nanoparticle is random and some spherical shape.

<p><span id="docs-internal-guid-2cebd816-7fff-d997-4dfd-796d046d0d3b"><span>Daun pucuk idat merupakan tanaman lokal Bangka Belitung yang memiliki aktivitas antibakteri terhadap </span><span>Staphylococcus aureus </span><span>dan</span><span> Escherichia coli.</span><span>Sebagai upaya pemanfaatan potensi lokal maka dibuat suatu produk sediaan gel </span><span>hand sanitizer</span><span> yang praktis dan ekonomis. </span><span>Ekstrak daun pucuk idat diperoleh dengan metode maserasi menggunakan pelarut aseton. Ekstrak yang dihasilkan diformulasikan dalam berbagai konsentrasi ekstrak daun pucuk idat (40%, 60%, 80%, dan 100%) dengan penambahan </span><span>carboxymethyl cellulose sodium</span><span> (</span><span>CMC-Na) 0,25 g, gliserin 1 mL, propilenglikol 0,5 mL serta akuades        10 mL. Setiap formulasi gel </span><span>handsanitizer</span><span> dilakukan pengujian stabilitas fisik meliputi uji organoleptis, uji homogenitas, uji daya sebar, uji pH, uji iritasi kulit serta uji aktivitas antibakteri.</span><span> </span><span> Hasil uji organoleptik menunjukkan bahwa semua konsentrasi </span><span>hand sanitizer </span><span>berbentuk gel, berwarna kuning muda, berbau dan homogen. Uji pH dan daya sebar gel</span><span> hand sanitizer</span><span> telah memenuhi ketentuan SNI No. 06-2588. Pengujian iritasi kulit tidak menimbulkan kemerahan, gatal-gatal dan tidak mengakibatkan kulit menjadi kasar pada punggung tangan sukarelawan. Berdasarkan uji sifat fisik gel</span><span> hand sanitizer </span><span>yang dihasilkan memiliki sifat fisik yang serupa dengan gel </span><span>hand sanitizer </span><span>komersial. Hasil uji antibakteri hand sanitizer ekstrak daun pucuk idat terhadap </span><span>E. coli</span><span> dengan konsentrasi ekstrak daun pucuk idat 40%, 60%, 80%, dan 100% diperoleh diameter zona hambat berturut-turut sebesar 11,5 mm, 17,4 mm, 19,3 mm dan 19,3 mm, sedangkan pada bakteri </span><span>S. aureus</span><span> diperoleh diameter zona hambat berturut-turut sebesar 17,1 mm, 24,2 mm, 27,4 mm, dan  18 mm. Hasil uji antibakteri menunjukkan bahwa sediaan gel </span><span>hand sanitizer </span><span>ekstrak aseton daun pucuk idat memiliki aktivitas antibakteri terhadap bakteri </span><span>E. coli </span><span>dan </span><span>S. aureus</span><span>.</span></span></p><p><span><span><span id="docs-internal-guid-50d6ff2c-7fff-2e66-45f1-73cf49e6527a"><strong>Hand Sanitizer of Leaves Extract of Cratoxylum glaucum as Antibacterial of Staphylococcus aureus and Escherichia coli. </strong><span>Cratoxylum glaucum</span><span> leaves is local plants of Bangka Belitung which have antibacterial activity against </span><span>S. aureus</span><span> and </span><span>E. coli</span><span>. As an effort to explore local potential, a practical and economical gel hand sanitizer product was prepared. </span><span>Cratoxylum glaucum</span><span> leaves extract was obtained by maceration method using acetone. The extract was formulated in various concentrations of </span><span>Cratoxylum glaucum</span><span> leaf extract (40%, 60%, 80%, and 100%) with the addition of 0.25 g carboxymethyl cellulose sodium (CMC-Na), 1 mL glycerin, 0.5 mL propylene glycol and 10 mL distilled water. Each concentration of the hand sanitizer gel was tested for physical stability including organoleptic, homogenity, spreadability, pH, skin irritation and antibacterial activity test. The organoleptic test results showed that all concentrations of hand sanitizers formed gel with light yellow color, smelly odor and homogeneous form. The analysis of pH and spreadability of hand sanitizer gel has fulfilled SNI No. 06-2588. The skin irritation testing does not cause redness, itching, and rough skin on the back of volunteer hands. Based on the physical properties test, the resulting hand sanitizer gel has physical properties similar to commercial hand sanitizer gel. The results of the antibacterial test of hand sanitizer against </span><span>E. coli</span><span> with </span><span>Cratoxylum glaucum</span><span> leaf extract concentrations of 40%, 60%, 80%, and 100% obtained the diameter inhibitory zones of 11.5 mm, 17.4 mm, 19.3 mm, and 19.3 mm, respectively. Meanwhile, the results of the antibacterial test of hand sanitizer against </span><span>S. aureus</span><span> bacteria with concentration of 40%, 60%, 80%, and 100% shows that the inhibition zone diameters were 17.1 mm, 24.2 mm, 27.4 mm, and 18 mm, respectively. The antibacterial test results shows that the gel hand sanitizer prepared has antibacterial activity against </span><span>E. coli</span><span> and </span><span>S. aureus</span><span> bacteria.</span></span></span></span></p>

<p>Synthesis nanosilver from <em>pelawan</em> leaf extract <em>(Tristaniopsis merguensis)</em> has been carried out. The variables of this study were variations in the concentration of AgNO₃ 1 mM, 1.5 mM and 2 mM. Pelawan leaf extract acted as a bioreductor that converts Ag⁺ to Ag⁰. The synthesis was carried out in a ratio of 1: 4 (opposition leaf extract: AgNO₃ solution) at 70 °C for 1.5 hours. The results of the UV-Vis analysis showed the maximum at the 1 mM; 1.5 mM; 2 mM AgNO₃concentration were 391 nm, 392 nm and 400 nm, respectively. XRD analysis explained that the resulting nanosilver was crystalline and according the Scherrer equation an average particle size was of 22.8 nm. The antibacterial activity test of nanosilver was carried out by disc method, nanosilver showed the existence of strong antibacterial activity against <em>E. coli</em> and <em>S. aureus</em> bacteria.</p><p>.</p>

Penggunaan polimer ramah lingkungan merupakan tantangan bagi industri baterai ion litium saat ini dikarenakan sifatnya yang mudah terbiodegradasi menjadi keunggulan polimer alam seperti kitosan dengan bahan baku dari alam yang melimpah. Komposisi polimer elektrolit dalam penelitian ini terdiri atas kitosan, PVA, gliserol yang didopan dengan LiClO4. Penelitian ini bertujuan untuk menganalisis sifat konduktivitas dan termal dari polimer elektrolit kitosan/PVA/gliserol/LiClO4. Pembuatan polimer elektrolit ini menggunakan metode casting. Peningkatan massa kitosan dalam komposisi polimer elektrolit menyebabkan adanya peningkatan intensitas pada bilangan gelombang 1718 cm-1 dan peningkatan intensitas serapan pada bilngangan gelombang 1271 cm-1 dengan masing-masing puncak serapan tersebut adalah gugus fungsi dari C=O dan gugus fungsi C-O.  Berdasarkan data konduktivitas menunjukkan bahwa komposisi 70/30/20/20 (kitosan /PVA/Gliserol/LiClO4) memiliki konduktivitas tertinggi sebesar 4,8 x 10-5S/cm. Hasil kurva TGA menunjukkan stabilitas termal komposisi polimer elektrolit hingga 210oC dan peningkatan jumlah kitosan dalam polimer elektrolit menurunkan kestabilan termal. Polimer elektrolit dari kitosan/PVA/Gliserol/LiClO4 dapat diaplikasikan untuk baterai ion litium berdasarkan analisis konduktivitas ionik dan kestabilan termal. ABSTRACT The use of environmentally friendly polymers is a challenge for the lithium-ion batteries industry today because its biodegradable nature is an advantage of natural polymers such as chitosan with abundant raw materials from nature. The polymer electrolyte composition in this study consisted of chitosan, PVA, glycerol doped with LiClO4. This study aims to analyze the conductivity and thermal properties of the polymer electrolyte chitosan/PVA/Glycerol/LiClO4. The polymer electrolyte was made using a casting method. The increasing of the chitosan mass in the polymer electrolyte composition led to an increase in intensity at the wave number 1718 cm-1 and an increase in absorption intensity at the wavenumber of 1271 cm-1 with absorption peaks being a functional group of C=O and C-O respectively. Based on the conductivity data, it showed that the composition of 70/30/20/20 (chitosan/PVA/Glycerol/LiClO4) had the highest conductivity of 4.8 x 10-5S/cm. The results of the TGA curve illustrated that polymer electrolyte had thermal stability until 210oC and the increasing amount of chitosan of polymer electrolyte decreased thermal stability. Polymer electrolyte chitosan

The increasing production of shrimp commodities in Bangka Belitung Island can cause shrimp shell waste and polluting the environment. Shrimp shell waste can further proceed into chitosan which has a wide range of functions in various fields. This current study aims to find out the influence of the deacetylation process in chitosan extracts from shrimp shell waste. The method of chitosan extraction by varying repetition of deacetylation process. The characterization of chitosan extracts by FTIR analysis to determine functional group and degree of deacetylation (DD). Based on FTIR spectra, repetition in the deacetylation process in chitosan extraction still produces chitosan extracts that do not fully transform into chitosan. However, it able to increase DD with the highest DD of chitosan extract constitutes 86,78% and can be used in the further application.