Browsing by Author "Yanti, Pepi Helza"

Now showing 1 - 9 of 9
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    Fabrication And Characterization Of Hydroxyapatite Nanopowder From Geloina Coaxans
    (2016-04-22) Yanti, Pepi Helza; Maylinda
    Fabrication and characterization of hydroxyapatite from Geloina coaxans and H3PO4 as precursors have been done. The main of chemical composition from Geloina coaxans shell was CaCO3, this material can be used as calcium source on fabrication of hydroxyapatite. Calcium oxide was obtained by calcination CaCO3 at 900oC for 12 hour. Synthesis of HAp was done with molar ratio of precursor 1,67 and pH of solution was adjusted at 11 with different stirring times (4 and 6) hours. Hydroxyapatite synthesized was characterized using XRD instrument, and the result proved that HAp nanopowder can be obtained successfully with stirring time for 4 hour with specific peak at 2θ = 31.7. Using Schererr equation, particle size of HAp powder was 26.42 nm. FTIR analysis was also done to determine functional group of HAp. The FTIR spectra of HAp powder obtained show there were characteristics band exhibited in sample spectra. Thermal analysis and particle size analysis were also investigated with TG-DTA and PSA instruments respectively. Analysis morphology by SEM revealed nearly uniform spherical morphology
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    PEMANFAATAN CANGKANG LOKAN (Geloina coaxans) UNTUK SINTESIS HIDROKSIAPATIT MENGGUNAKAN METODE PENGENDAPAN
    (2016-05-02) Maylinda, Nia; Awaluddin, Amir; Yanti, Pepi Helza
    The synthesis of hydroxyapatite (HAp) from seashell (Geloina coaxans) using precipitation method has been done . The seashell (Geloina coaxans) and H3PO4 were used as sources of calcium and phosphate. Molar ratio of precursor was 1.67. Product obtained was characterized using X-ray Diffraction (XRD) and FTIR. The results showed that the particle size of hydroxyapatite (HAp) using H3PO4 as precursor was 26.419 nm and degree of crystallinity was 89.90%. Analysis using FTIR revealed that hydroxyapatite (HAp) compounds have specific band of functional groups OH and PO43- in sample spectrum
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    Sintesis Dan Analisis Sifat Permukaan (Birnesite) Dan Pemanfaatan Limbah Ampas Tebu Sebagai Adsorben Untuk Menurunka Kandungan Asam Humat Dan Ion Logam Fe (Iii) Pada Air Gambut
    (2015-04-22) Yanti, Pepi Helza; Awaluddin, Amir; Mukhtar, Akmal; Sophia, Halida
    Mangan oksida sangat menarik untuk diteliti karena memiliki aplikasi yang sangat beragam. Aplikasi mangan oksida sangat erat kaitannya dengan struktur yang dimiliki oleh mangan oksida tersebut. Mineral mangan oksida terdiri atas berbagai struktur yaitu struktur berongga seperti hollandite, todorokite, cryptomelane, pyrolusite dan coronadite;struktur berlapis seperti busserite, birnessite, chalcophanite ,dan lithiophorite; serta struktur amorphous. Mangan oksida dengan bentuk struktur berongga seperti cryptomelane (2x2) dapat dimanfaatkan sebagai katalis, penukar ion, dan adsorben[1]. Mangan oksida berongga lainnya, dengan bentuk struktur rongga yang lebih besar adalah todorrokite. Todorrokite dengan ukuran rongga (3x3) memiliki luas permukan yang relatif besar (hingga 250 m2/g) sangat potensial digunakan sebagai katalis dan odsorben[2]. Mangan oksida dengan rongga paling kecil (1x1) adalah pyrolusite yang banyak digunakan pada industri gelas dan baterai. Mangan oksida dengan bentuk setruktur berlapis seperti birnessite dapat digunakan sebagai material penukar ion, material katoda untuk baterai lithium dan adsorben [3]. Birnesite juga digunakan sebagai prekursor yang digunakan dalam sintesis todorokite [4]. Pemanfaatan birnessite ini sangat ditentukan oleh sifat-sifat permukaan khas yang dimilikinya, seperti luas permukaan, morfologi, dari material birnessite. Namun demikian, salah satu permasalahan yang timbul adalah birnessite sulit ditemui dalam keadaan murni di alam, sehingga perlu analisis sifat permukaan digunakan birnessite yang telah disintesis. Sintesis mangan oksida dapat dilakukan dengan berbagai metoda, pada penelitian sebelumnya dengan menggunakan KMnO4 dan MnSO4 telah disintesis mangan oksida Holondite menggunakan metode hidrotemal [5], dengan metode yang sama prekursor Na-birnesite dan MgCl telah dihasilkan todorike [6]. Birnesite juga telah berhasil disintess dengan menggunaan KOH untuk mempelajari morfologi oleh mangan oksida berlapis dari cotton menjadi had platelike ]7]. Berdasarkan latar belakang di atas maka pada penelitian ini akan dilakukan sintesis dan analisis sifat permukaan mangan oksida –berlapis- dengan mengggunakan prekursor maltosa sebagai reduktor. Analisis terhadap sifat birnessite diamati terhadap karakterisasi, XRD, FTIR, TGA-DTA dan AAS.
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    SINTESIS DAN KARAKTERISASI KOMPOSIT HIDROKSIAPATIT-KITOSAN DAN UJI EFEKTIVITAS DAYA SERAP TERHADAP METILEN BIRU MELALUI VARIASI MASSA
    (2020-12) Dari, Sri Wulan; Yanti, Pepi Helza
    Composite is a material that is formed from two or more combination materials with the result that it is resulted a composite material that has different mechanical and characteristic properties from the forming material. The purpose of this research is to conduct hydroxyapatite synthesis from lokan shells (Geloina coaxans) using the method of microwave with Diammonium hydrogen phosphate (NH4)2HPO4 precursor and Ca(OH)2 and for adsorption of hydroxyapatite/chitosan as adsorben toward methylene blue. Hydroxyapatite/chitosan (HAp-C) synthesis result of is characterized X-Ray Floresence (XRF) contain is CaO 98,759 %, used to adsorb methylene blue with an adsorption ability of 71,1296 %
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    SINTESIS DAN UJI ADSORPSI METILEN BIRU PADA KOMPOSIT HIDROKSIAPATIT-GELATIN (K-HAp/Gel) MELALUI VARIASI MASSA ADSORBEN
    (2020-10) Aspama, Rifa; Yanti, Pepi Helza
    Composite is a material that is formed from two or more materials with different properties, so that a material with different properties and characteristics is produced. Composite consists of reinforcement and a matrix. In this study, hydroxyapatite was acted as a matrix and the reinforcement was derived from gelatin. The purpose of this study was to synthesize hydroxyapatite-gelatin composites using the microwave method with prekursor (NH4)2HPO4 dan Ca(OH)2 precursors and also the adsorption test on methylene blue. The results of the analysis of the chemical composition of the shellfish contained CaO (97.368%). Based on the results of adsorption of methylene blue using hydroxyapatite-gelatin composites, the optimum conditions for each of the adsorbent mass variations were obtained, at K-HAp / Gel 0% was 10 mg (60.612%); K-HAp / Gel 10% is 5 mg (76.593%); K-HAp / Gel 20% is 10 mg (77.110%) while for K-HAp / Gel 30% is 25 mg (79.903%).
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    SINTESIS KOBAL OKSIDA (Co3O4) DAN UJI DEGRADASI PADA METANIL KUNING
    (2016-05-16) Prasanti, Astarina Atik; Mukhtar, Akmal; Yanti, Pepi Helza
    The synthesis of cobalt oxides by precipitation method have been done. (Co(NO3)2.6H2O and KOH was used as precursors in synthesis. Molar ratio of precursors 1:1 M. Temperature of calcination at 900oC was done to deteminate the crystalinity of cobalt oxides. The powder obtained were analyzed using XRD, size of particle of cobalt oxide was examined with Scherrer equation. The result revealed that temperature of calcination at 900 oC have highest intensity of Co3O4 minerals and size of particle was 40,47 nm. The optimum of time irradiation at 60 minute with mass of Co3O4 0,008 g the percentage is 20,06.
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    SINTESIS TEMBAGA OKSIDA (CuO) SERTA UJI DEGRADASI TERHADAP METANIL KUNING
    (2016-05-02) Kurniati, Titin; Mukhtar, Akmal; Yanti, Pepi Helza
    Degradation of methanil yellow solution had been done by photocatalytic using CuO as catalyst. CuO was synthesized by precipitation method using as copper nitrate (Cu(NO3)2.3H2O) with precipitator NaOH molar ratio of precursors 1:1 M at calcination temperature 700 ℃ until 1 hour and characterized by X-ray Diffraction (XRD). The result obtained were analyzed using XRD and size of crystallinity of copper oxide (CuO) was examined with Scherrer equation obtained crystal size of CuO was 67,37 nm and result of degradation test from methanil yellow obtained optimum mass of CuO is 0,008 g, optimum time is 60 minute with percentage degradation 20,19% and 16,90%.
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    SINTESIS TIMBAL OKSIDA (PbO) SERTA UJI DEGRADASI TERHADAP METANIL KUNING
    (2016-05-02) Lisniwari; Mukhtar, Akmal; Yanti, Pepi Helza
    Photodegradation has good potential for the degradation of organic pollutants such as dyes. Catalyst used in the degradation is a semiconductor. In this study, the semiconductor used is PbO, that was synthesize using the precipitation method from precursor Pb(NO3)2 with NaOH precipitator and temperature calcination at 700℃ until 1 hour. The powder obtained were analyzed using XRD and size of crystallinity of lead oxide (PbO) was examined with Scherrer equation. From the result of XRD data that were calculated using Scherrer equation it was obtained crystal size of PbO is 26,52 nm and from the degradation to methanil yellow was obtained the optimum mass of PbO is 0,008 g, optimum time is 60 minutes with percentage degradation of 19,89% and 10,78%.
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    SYNTHESIS PRECIPITATED CALCIUM CARBONATE (PCC) USING LISIN AS DIRECTING AGENT
    (2014-05-21) Yanti, Pepi Helza; Jamarun, Novesar; Arief, Syukri
    Synthesis Precipitated Calcium Carbonate have done using lisin as source of amino acid with modification of caustic soda method. The limestone are first calcinated by XRF to analysis composition of limestone. The result showed CaO of limestone 55,26%. Analysis using FT-IR proved a pure crystal without contain lisin. Analysis using XRD showed optimum peak 2θ = 29,48300 .The particle size of lisin 0,05 M 68,56 nm with 88.21% calsit and 11.79% vaterit while particle size of Lisin 0.150 M 57.13 nm with 80.12% calsit and 19.89% vaterit. Based on our research proved that lisin can be used as directing agent to produce PCC. Key words: calcination, caustic soda , directing agent, lisin, PCC