Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
This is a book on the dissipative dynamics of ordered fluids, with a particular focus on liquid crystals. It covers a whole range of different theories, mainly concerned with nematic liquid crystals in both their chiral and nonchiral variants. The authors begin by giving a detailed account of the molecular origins of orientational order in fluids. They then go on to develop a general framework in which continuum theories for ordered fluids can be phrased.

Abstrak :
Ni(II)-Ion Imprinted Polymer disintesis dengan kopolimerisasi monomer stirena dengan pengikat silang etilen glikol dimetakrilat (EGDMA) dengan adanya kompleks terner Ni(II)-dimetil glioksim-4-vinil piridin (Ni(II)-DMG-4VP) menggunakan metode polimerisasi presipitasi dengan pelarut etanol, diinisiasi oleh inisiator termal 2,2-azobisisobutironitril (AIBN). Ion Ni(II) yang menjadi ion template dilepaskan dengan HCl 6,0 M. Dilakukan pengujian parameter adsorpsi seperti pH, waktu kontak, konsentrasi ion Ni(II) serta massa adsorben. Pengujian kadar logam ditentukan dengan Spektrofotometer Serapan Atom. Uji pendahuluan adsorpsi menunjukkan kemampuan adsorpsi yang baik pada Ni(II)-IIP yaitu >99 % dan NIP (Non Imprinted Polymer) yaitu 92,56 %. Adsorpsi maksimum Ni(II)-IIP dan NIP tercapai pada pH 8 dan waktu kontak 120 menit. Adsorpsi Ni(II)-IIP dan NIP mengikuti model isoterm adsorpsi Langmuir dengan kapasitas adsorpsi maksimum Ni(II)-IIP yaitu 19,9203 mg/g sedangkan NIP yaitu 21,0971 mg/g. Uji ion pengganggu Co(II) terhadap adsorpsi ion Ni(II) menghasilkan penurunan adsorpsi dari 96,31 % (IIP) dan 82,38 % (NIP) menjadi 89,51 % (IIP) dan 74,00 % (NIP). Uji ion pengganggu Fe(III) terhadap adsorpsi Ni(II) tidak menunjukkan penurunan adsorpsi pada Ni(II)-IIP (>99%) sedangkan untuk NIP menurun dari 98,19 % menjadi 75,09 %. Uji selektifitas terhadap ion logam lain menunjukkan urutan adsorpsi yaitu Ni(II) > Cu(II) > Fe(III) > Zn(II) > Co(II). Uji selektifitas menunjukkan ion Ni(II) dapat diserap lebih efektif dibanding logam lainnya baik dalam campuran biner kedua logam ataupun campuran kelima logam tersebut. Meskipun adsorpsi Ni(II)-IIP terhadap logam lain juga tinggi namun tidak mengganggu adsorpsi ion Ni(II) yang menunjukkan afinitas adsorben terhadap ion yang menjadi template.

---

Ni(II)-Ion Imprinted Polymer was synthesized by copolymerization of styrene as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinker in the presence of ternary complexes Ni(II)-dimethyl glyoxime-4-vinyl pyridine (Ni(II)-DMG-4VP) using precipitation polymerization method and ethanol as a solvent, initiated by thermal initiator 2,2-azobisisobutyronitrile (AIBN). Ni(II) ion used as template ion was removed by HCl 6,0 M. Adsorption parameters such as pH, contact times, concentration of Ni(II) ion, and adsorbent mass, have been studied. The amount of metal ion in aqueous samples was measured by FAAS. The initial adsorption study showed that both Ni(II)-IIP and NIP (Non Imprinted Polymer) have good capability to adsorb Ni(II)-ion resulting >99% (IIP) and 92,56 % (NIP) adsorption. Maximum adsorption was reached at pH 8 with contact times 120 minutes for both Ni(II)-IIP and NIP. Adsorption of Ni(II)-IIP and NIP followed Langmuir isoterm with maximum capacity 19,9203 mg/g (IIP) and 21,0971 mg/g (NIP). Interference study for Co(II) ion showed that adsorption of Ni(II) ion decreased slightly from 96,31 % (IIP) and 82,38 % (NIP) to 89,51% (IIP) and 74,00 % (NIP). Interference study for Fe(III) showed that Ni(II) adsorption did not decrease for Ni(II)-IIP while NIP showed decrease from 98,19 % to 75,09 %. Selectivity studies showed adsorption in order Ni(II) > Cu(II) > Fe(III) > Zn(II) > Co(II). Ni(II) ion could be adsorbed more effective in binary mixed of two ions or when all of them were mixed. Although high percent adsorption of Ni(II)-IIP was also obtained for other metals, Ni(II) ion adsorption was not interfered which showed that the adsorbent has adsorption affinity towards template ion.

Abstrak :
Latar Belakang: Polymer Induced Liquid Precursor (PILP) merupakan remineralisasi biomimetik dengan menggunakan bahan polimer anionik sintetik yang dapat menggantikan peran protein non kolagen dalam remineralisasi intrafibrillar. Asam poliaspartik merupakan salah satu material analog protein non kolagen yang penting dalam proses PILP. Nanodroplet yang terbentuk dalam proses PILP mampu berdifusi ke dalam intrafibrillar kolagen ataupun gap zone yang memiliki ukuran 40 nanometer dan mengalami kristalisasi. Tujuan: Menganalisis remineralisasi intrafibrillar dan ukuran kristal hidroksiapatit yang terbentuk. Metode: Evaluasi efek asam poliaspartik dalam proses PILP pada remineralisasi intrafibrillar selama 3, 7 dan 14 hari melalui TEM dan ukuran kristal hidroksiapatit yang terbentuk melalui XRD. Hasil: Ada perbedaan signifikan secara evaluasi deskriptif antar kelompok remineralisasi 3, 7 dan 14 hari terhadap kelompok demineralized dentin pada remineraliasi intrafibrillar. Tidak terdapat perbedaan bermakna antar kelompok remineralisasi maupun kelompok demineralized dentin terhadap ukuran kristal hidroksiapatit. Kesimpulan: Asam poliaspartik dalam proses PILP memiliki potensi dalam remineralisasi intrafibrillar. ......Background: Polymer Induced Liquid Precursor (PILP) is a biomimetic remineralization using synthetic anionic polymer material that can replace the role of non-collagen proteins in intrafibrillar remineralization. Polyaspartic acid is one of the non collagen protein analog materials that is important in the PILP process. Nanodroplet formed in the PILP process is able to diffuse into intrafibrillar collagen or gap zones that have a size of 40 nanometers and crystallize. Purpose: To analyze the intrafibrillar remineralization and the size of hydroxyapatite crystal formed. Methods: Evaluation of the effect of polyaspartic acid in PILP process on intrafibrillar remineralization for 3, 7 and 14 days through TEM and the size of hydroxyapatite crystal formed through XRD. Result: There was a significant difference in descriptive evaluation between remineralization groups of 3, 7 and 14 days against the demineralized dentin group in intrafibrillar remineralization. There were no significant differences between the remineralization group and the demineralized dentin group to the size of hydroxyapatite crystals. Conclusion: Polyaspartic acid within PILP process has potential ability in intrafibrillar remineralization.

Abstrak :
This book about preparation of liquid crystalline elastomers, applications of liquid crystalline elastomers, liquid crystal elastomers and light, electro-opto-mechanical effects in swollen nematic elastomers, the isotropic-to-nematic conversion in liquid crystalline elastomers, and order and disorder in liquid-cystalline elastomers.

Abstrak :
Metode analisa kuantitatif terhadap polimer terns dikembangkan mengingat betapa meningkatnya kebutuhan polimer di masyarakat. Salah satu metode yang digunakan adalah metode analisa kuantitatif spektroskopi IR. Metode ini mudah , cepat, dan relatif lebih murah.dibanding metode analisa polimer lainnya. Penelitian ini bertujuan mengembangkan metode analisa kuantitatif IR untuk menentukan komposisi kopolimer dalam hal ini adalah kopolimer propilen-etilen blok (KPEB) dan derajat poiimerisasi (MSLiK peRPU5TAi

Abstrak :
ABSTRACT We studied ultrathin layers of 𝑛 cyanobiphenyl (𝑛 = 5,6,7,8) mesogene molecules forming thin films on a graphene plane using molecular dynamics simulations in a wide temperature range (220 420 K). Each modeled ensemble was heated to the maximum temperature and then cooled (reverse procedure). We calculated the second rank order parameter as a measure of the molecular order of mesogene molecules and we discuss the distribution of angles between them and the global sample director.

Abstrak :
This book about fluorinated liquid crystals : design of soft nanostructures and increased complexity of self-assembly by perfluorinated segments, liquid crystalline crown ethers, star-shaped mesogens – hekates : the most basic star structure with three branches, DNA-based soft phases, phases made of bent-core mesogens, achiral symmetry breaking in liquid crystalline phases, and nanoparticles in liquid crystals and liquid crystalline nanoparticles, stimuli-responsive photoluminescent liquid crystals.