Journal of Nanomaterials & Molecular Nanotechnology最新文献

{"title":"Bio-Synthesis of Silver Nanoparticle Using Azadirachta indica Leaves","authors":"N. Geetha, D. Prakash, Kumar Vs","doi":"10.4172/2324-8777.1000263","DOIUrl":"https://doi.org/10.4172/2324-8777.1000263","url":null,"abstract":"In this study, simple approach was attempted to obtain a green eco-friendly way for the bio-synthesis of metal nanoparticles (AgNPs) from bioreduction of AgNO3 solutions using Azadirachta indica leaf extracts. The formation of nanoparticle and its stability were examined through UV-Visible spectra, FTIR spectra, and Zeta potential measurements. The exposure of metal ions to these plant extract by UV-Vis confirmed the presence of silver nanoparticles. FTIR revealed the reduction of silver ions, the functional groups present in the plant extract. The stability of the AgNPs was confirmed with the zeta potential measurement.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"41 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2019-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75520973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological Characterization of Nanointerconnects Formed at the Interface of Sn Coated Multiwalled Carbon Nanotubes on an Etching Mask Patterned on a Si Substrate","authors":"M. Us, Li-Jie Ci, Lin Kl","doi":"10.4172/2324-8777.1000265","DOIUrl":"https://doi.org/10.4172/2324-8777.1000265","url":null,"abstract":"Tin-coated multiwalled carbon nanotube (SnO2/MWCNT) composites were synthesized by precipitation of SnCl2 within a CNT suspension in the first stage. An efficient dispersion technique using trifluroacetic acid (TFA) has been employed for the homogenous dispersion of Sn coated multiwalled carbon nanotubes (MWCNT) on an etching mask patterned on Si wafer using AZ 1500 as a photoresist. The MWCNT suspension was dispersed homogenously on the patterned Si wafer and the formation of nano-interconnects or nanojoints were clearly established by high-resolution transmission electron spectroscopy (HRTEM). High Resolution Transmission Electron Microscopy (HRTEM) images demonstrated that nano-interconnects formed between two MWCNTs consisted of both tetragonal Sn and orthorhombic SnO2 phase. .Elemental Sn was observed at the interface of two multiwalled carbon nanotubes by reduction of SnO2/MWCNTs under a reflow atmosphere. The interfacial interaction between the graphene layers in the carbon nanotubes and metallic Sn/oxides were also investigated. Raman spectroscopy studies established the interfacial interaction between MWCNT and the metallic Sn. The results revealed that the strong interaction between MWCNT and Sn lowered the ID/IG ratio in MWCNTs. The multiwalled carbon nanotubes were found to be well connected to each other on the patterned mask and this phenomenon could throw new light on the conductivity of carbon nanotubes in electronic circuits.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"225 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2019-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76734350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facile Synthesis of 1D and 2D Zinc Sulfide Nanostructures on Multi-Layered Graphene","authors":"Allon Sm, H. Al-Shukaili, T. Mohiuddin, S. Karthikeyan, R. Al-Busaidi","doi":"10.4172/2324-8777.1000266","DOIUrl":"https://doi.org/10.4172/2324-8777.1000266","url":null,"abstract":"ZnS nanostructures have been fabricated over multi-layered graphene substrate via chemical vapor deposition technique. A controllable morphology of grown ZnS nanostructures, including (1D) nanowires, (2D) discs and nano-flakes were achieved by direct carbo-thermal evaporation of (1:1) ZnS and graphite powders mixture. The substrate location and therefore its temperature was found as a crucial growth parameter, which controls the morphology of the grown ZnS Nanostructures. The average diameter of the ZnS 1-D nanowires, at T= 400 °C, 2-D planar filling nano-discs, at T=300 °C, are 0.418 ± 0.007 μm, 0.600 ± 0. 020 μm respectively. At lower substrate temperature, <300 °C, a periodic round shaped features or flakes with some nanowire at their edges were formed due to nanodiscs amalgamation. This is because at a lower temperature, higher liquid instability leads to more nucleation sites and high conversion rate from liquid to solid state and therefore small nano-discs will merge to form larger flake structure. All products are cubic sphalerite ZnS in structure and with preferentially intense (111) planes. The lattice parameter for (220) planes was 5.72 A with 5.92% strain % clearly indicate that they are in tensile stress region. Raman was utilized to define the existence of graphene layers and the ZnS nanostructures (Magnified range100-700 cm-1) on top of multigraphene layers before and after growth process. In addition, ZnS nanostructures PL emissions of violet and cyan-blue centered at 3.23ev and (2.41-2.53ev) respectively were detected and attributed to defects such as Zn2+ vacancies, S2− interstitials, and dislocations. Graphene-based inorganic hybrid nanostructures deliver several potential applications in optoelectronics and nanoscale electronics such as photodetectors, photovoltaic and optical devices.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"58 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2019-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81276693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the UV-Vis Spectroscopy for Nanoparticles","authors":"Q. Abbas","doi":"10.4172/2324-8777.1000268","DOIUrl":"https://doi.org/10.4172/2324-8777.1000268","url":null,"abstract":"UV-Vis technique is a compulsory technique for the optical study of the materials. Optical study helps the researcher for the application s of nanomaterials for different uses. Different devices are fabricat- ed on the basis of optical properties of the materials especially solar cells. With the help of this technique optical band gap can be calcu- lated which helps to choose the materials for the energy conversion purpose like light energy to electrical energy in solar cell. Also, from this technique purity of the sample can be measured by comparison with the reference solution. Here results of different materials are described which can help to better understand the analysis of Uv- Vis spectroscopy results.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"45 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2019-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75689615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Ohmic Contact Fabrication for Al0.3Ga0.7N/AlN/GaN HEMTs on 6H-SiC Using Recess Etching and Surface Plasma Treatment Processes","authors":"Gunjan Rastogi, R. Kaneriya, Santanu Sinha, R. Upadhyay","doi":"10.4172/2324-8777.1000267","DOIUrl":"https://doi.org/10.4172/2324-8777.1000267","url":null,"abstract":"Ohmic contacts to AlGaN/AlN/GaN heterostructures with low contact resistance and smooth surface morphology play a vital role in the development of high power, high frequency GaN transistors. In the present work, two different Ohmic contact fabrication techniques, recess etching and surface plasma treatment, are optimized in order to obtain good Ohmic contact performance on undoped AlGaN/AlN/ GaN heterostructure on 6H-SiC substrate.For Ohmic contact fabrication, Ti/Al/Ni/Au metallization scheme is studied under optimized Rapid Thermal Annealing (RTA) temperature and time. Three samples are prepared with different recess based process flow and surface plasma treatment. Standard Transmission Line Model (TLM) is used for computation of contact resistance, sheet resistance and specific contact resistance of Ohmic contacts. For the first time, we explored feasibility of surface plasma treatment process for fabricating Ohmic contacts on AlGaN/ AlN/GaN based heterostructures. We achieved contact resistance of around 0.27 Ω*mm. Further to it we realized improvement in contact resistance on AlGaN/AlN/GaN based heterostructures using recess etching and achieved contact resistance of around 0.25 Ω*mm using Ti/Al/Ni/Au metal stack. Based on the characterization results it is also observed that surface plasma treatment process is a good alternative of comparatively complex recess etching process in fabricating Ohmic contacts for AlGaN/AlN/GaN based High Electron Mobility Transistors (HEMTs).","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"20 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2019-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85874758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication and Evaluation of Cassava Starch Acetate Nanoparticles Loaded with Drugs of Various BCS Classes: Influence of Drug Solubility and Partition Coefficient","authors":"G. Paulos, T. Gebre-Mariam, Neubert Hhr","doi":"10.4172/2324-8777.1000259","DOIUrl":"https://doi.org/10.4172/2324-8777.1000259","url":null,"abstract":"A successful fabrication of nanocarrier for drug delivery should yield nanoparticles (NPs) with suitable particle size and size distribution and provide high drug-loading capacity. Factors that influence these attributes include physicochemical properties of the drug, the nature of the nanocarrier, and processing variables, among others. The aim of this study was, therefore, to investigate the influence of solubility and partition coefficient of different drugs on the characteristics of starch-based NPs. Cassava starch was chemically modified by acetylation, at different degrees of substitution (DS) and characterized. The starch acetates (SAs) were then used for the preparation of drug-loaded NPs. Different model drugs: ibuprofen (BCS class II), acyclovir (BCS class III) and furosemide (BCS class IV) were incorporated into NPs using emulsification solvent evaporation technique. The effects of solubility and partition coefficient, and DS of SA on the properties of NPs, namely, size and size distribution, drug loading capacity (DL), encapsulation efficiency (EE) and in vitro release profile were investigated. The results showed that the DL and EE of ibuprofen and furosemide loaded starch acetate nanoparticles (SANPs) increased consistently with an increase in the DS of SA. On the contrary, DL and EE of acyclovir-loaded NPs decreased as DS of SA increased. Due to their poor solubility and high partition coefficient, the EEs of ibuprofen and furosemide in SANPs fabricated from SA with high DS were much greater than that of acyclovir. Furthermore, as DS of SA increased the cumulative release profile of Ibuprofen from SANPs was retarded whereas the release profile of acyclovir was enhanced. On the other hand, furosemide, the most lipophilic drug of all, exhibited lowest release profile over the study period of 8 h. In conclusion, along with the hydrophobic nature of SA, the DL, EE and drug release profile from SANPs depended on the solubility and partition coefficient of the incorporated drug molecule.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"7 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89024800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Perspectives on the Unique Micro and Nano-Structural Features of the Cu/ZnO Methanol Synthesis Catalyst","authors":"G. Mr.","doi":"10.4172/2324-8777.1000260","DOIUrl":"https://doi.org/10.4172/2324-8777.1000260","url":null,"abstract":"The vapor phase methanol process, introduced by ICI technology in 1966, and the liquid phase methanol synthesis process (LPMeOHtm) introduced first by ChemSystems, Inc. (now Nexant) in 1975, are seen as the 2 big research/technology advances in the conventional methanol synthesis technology. The success of these 2 processes, both from a scientific and commercial standpoint, primarily is driven by the very superior, almost anomalous, performance of the proprietary Cu/ZnO/Al2O3ICI technical catalyst, and it’s very unique microstructural features, often termed as a “microcrystalline sponge”. The LPMeOHtm process overcomes some of the glaring drawbacks associated with the vapor phase process, viz., highly exothermal nature of methanol synthesis reactions, presence of local reactor hot spots which presents possibility of thermal runaways, and low per-pass CO/H2 conversions.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"15 1","pages":"1-12"},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78698943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas Sensing Properties of MoO3: NiO Nanocomposite Functionalized with Noble Metal towards Carbon Dioxide (CO2)","authors":"Manasa Mv, Devi Gs","doi":"10.4172/2324-8777.1000262","DOIUrl":"https://doi.org/10.4172/2324-8777.1000262","url":null,"abstract":"In the present study we describe the design, fabrication and gas sensing performance of p-NiO/n-MoO3 (MN) nanocomposites functionalized by noble metal Pt (MNP). The formation of the nanocomposite was systematically reviewed and confirmed by X-Ray Fluorescence Spectroscopy (XRF) and X-Ray Diffraction (XRD) pattern. The MN nanocomposite impregnated with noble metal - Pt (MNP) showed better efficiency of S=92% towards Carbon dioxide (CO2) gas compared to MN (S=80) and selectivity towards CO2 in comparison to other interfering gases i.e., H2, EtOH, MeOH, NH3 and LPG, with superior stability.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"8 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89681620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the Dependency of pH Values on HAp Synthesis","authors":"M. Kamrujjaman, Kh., aker Ji, Haque Mm, R. Mo, Rahman Mm","doi":"10.4172/2324-8777.1000258","DOIUrl":"https://doi.org/10.4172/2324-8777.1000258","url":null,"abstract":"Hydroxyapatite (Ca10(PO4)6(OH))2, HAp has been one of the cheapest and well-known ceramics for diversified applications including clinical bone graft procedures for more than 30 years. Synthetic calcium phosphates, such as calcium hydroxyapatite, are an important inorganic biomaterial which has attracted the attention of researchers related to the biomaterials field in recent years. HAp is widely used for hard tissues repair due to its chemical and structural similarity with the mineral phase of bone and teeth. As a result, this inorganic phosphate has been studied extensively for medical applications in the form of powders, composites, and coatings [1–11]. HAp has many bone replacement applications and is used as bone substitutes in dental and orthopedic sites, immediate tooth replacement, augmentation of alveolar ridges, pulp capping material and maxillofacial reconstruction, etc. [12]. HAp implants exhibit relatively good tissue compatibility, and new bone is formed directly on the implants [13-19]. For repairing or substituting the bone, the designed HAp material must have the ability to create a bond with the host living bone [20]. Hence, it is desirable to include a high degree of crystallinity and chemical stability among the desirable properties of an ideal hydroxyapatite [21-23] HAp has poor mechanical properties, e.g., low strength and toughness, restrict monolithic HAp applications to those that require little or no load-bearing parts [24]. Due to its diverse applications, the materials properties accordingly need to be tailored for an application. Hence, researchers have tried to customize its properties such as bioactivity, mechanical strength, solubility and sinter ability by controlling its composition, particle size and morphology [9,10]. The objectives of this work are to synthesize hydroxyapatite nanoparticles by chemical precipitation method for different pH value and to investigate the effects of the pH value variation during the reaction.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"55 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73287726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chitosan Nanoparticles as a Potential Drug Delivery System for Photodynamic Therapy of Cancer","authors":"G. Amsaveni, M. Sakthivel, K. Kathiravan, B. Anish, R. Murugesan","doi":"10.4172/2324-8777.1000261","DOIUrl":"https://doi.org/10.4172/2324-8777.1000261","url":null,"abstract":"Objective: Chitosan nanoparticles (CS-NP) can imbibe water insoluble anticancer agents into its hydrophobic multicores. In the present study, chitosan nanoparticles, a nanoscale drug carrier system is investigated for its potential as a drug delivery system for porphyrin based photodynamic therapy. Methods: Zinc meso tetra phenyl porphyrin (ZnmTPP) encapsulated CS-NP was prepared by ionic gelation method. The synthesized nanoparticles were characterized using dynamic light scattering studies, zeta potential analysis and AFM analysis. Results: Freshly prepared chitosan nanoparticles had an average hydrodynamic diameter of 175 nm and are nearly spherical in shape as per light scattering measurements and atomic force imaging respectively. As nanoscale drug carriers, (ZnmTPP) encapsulated chitosan nanoparticles exhibited high encapsulation efficiency and controlled release pattern. The encapsulated photosensitizer exhibited efficient singlet oxygen generation upon photo irradiation, retaining the photosensitization capacity of encapsulated hydrophobic ZnmTPP. The in vitro phototoxicities of free and nano-encapsulated ZnmTPP, studied using MTT assay in DLA cell lines demonstrate a concentration dependent response of photosensitizer in free and CS-nano formulations.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":"100 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76568400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}