Processing Of Organic Materials Research Articles

A UV-XUV attosecond beamline with few-femtosecond tunable ultraviolet pump pulses

Ultrafast charge transfer processes in organic materials which occur in organic materials are fundamental for advancing solar energy conversion technologies. Understanding these phenomena on a short time scale induced by visible and ultraviolet (UV) light is crucial for future control and engineering of these molecules. Here, we present a novel attosecond beamline featuring Resonant Dispersive Wave emission for generating sub-3 fs tunable pump pulses in the UV region and High Harmonic Generation (HHG) in a semi-infinite gas cell for isolated attosecond pulse generation in the Extreme ultraviolet range.

In situ characterization of phase transformations in petroleum pitch by high temperature X-ray diffraction

The phase transformation from isotropic to mesophase of a petroleum-derived pitch was monitored by in situ X-ray diffraction at 410 °C. The kinetics of the transformation were characterized by monitoring the growth of a broad peak at 2θ∼24° and could be described by Avrami’s equation. The volatilization of low molecular weight components originally present in the pitch, or produced during the condensation reaction, was assessed by thermal gravimetry analysis, following the same thermal history. Ex situ characterizations of the pitch precursor before and after thermal treatment provided insight into the evolution of the molecular structure associated with mesophase generation (optical polarized microscopy, molecular weight distribution by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, X-ray photoelectron spectroscopy, Auger spectroscopy, and thermal stability). This investigation demonstrates the value of using complementary in situ and ex situ experimental techniques to characterize complex mechanisms during the processing of organic materials.

Nonradiative Recombination via Charge‐Transfer‐Exciton to Polaron Energy Transfer Limits Photocurrent in Organic Solar Cells

AbstractA recombination and exciton loss mechanism is reported in organic solar cells involving energy transfer between charge transfer (CT) excitons and polarons, impacting photocurrent generation, particularly in the near‐infrared where polaronic transitions typically reside. This process sets a low‐energy cut‐off in the external quantum efficiency spectrum of an excitonic donor/acceptor interface, determined by the low‐energy polaron absorption peak and the CT state reorganization energy. Furthermore, this process explains the deviation from unity and bias dependence of the CT state's internal quantum efficiency at low photon energies. This process is demonstrated in a variety of systems and it is hypothesized that CT state to polaron energy transfer recombination may be responsible for a share of nonradiative recombination in all organic photovoltaics and can explain numerous experimentally observed device trends regarding photocurrent generation and energy losses. Overall, this work enhances the understanding of photophysical processes in organic materials and allows the design of systems that can avoid this recombination pathway.

An analysis of effect of water hyacinth carbonization temperature on fabrication and EMI shielding radar

The need to increase the ability of water hyacinth composites as EMI radar protection is related to the carbonization process of organic materials. This research aimed to determine the effect of water hyacinth carbonization temperature on the effectiveness of fabrication and EMI shielding radar. The research method includes the preparations such as cutting, washing, and drying the water hyacinth. The drying process is carried out using an oven with a temperature of 70 °C for 4 days. Then the water hyacinth is mashed until it reaches the 80 mesh size. Then the carbonization process is carried out, with variations in carbonization temperature ranging from 500 °C, 600 °C, 700 °C, 800 °C, 900 °C and 1,000 °C, with a heat increase speed of 3 °C/minutes. After reaching the specified temperature, a holding time is then carried out for 1 hour. Furthermore, the composite composition of 30 % water hyacinth activated carbon powder and 70 % phenol-formaldehyde (PF) resin was molded using a hot press with a pressure of 300 kg/cm2 at 180 °C for 10 minutes. The results showed that the water hyacinth composite could be used as an EMI protection material at the X-Band frequency (8–12.5 GHz). Where the electrical conductivity and EMI SE increases with increasing carbonization temperature. Water hyacinth composites at a carbonization temperature of 1,000 °C showed the highest electrical conductivity and the highest EMI SE, respectively 4.64∙10-2 S/cm and 41.15 dB (attenuation 99.99 %) at a frequency of 8 GHz. The high absorption contribution is associated with the synergy combination of KCl and the pore structure of the goitre. KCl contributes to the magnetic properties and pore structure with high electrical conductivity values

Tuning ambipolarity in a polymer field effect transistor using graphene electrodes

Polymer field-effect transistors with 2D graphene electrodes are devices that merge the best of two worlds: on the one hand, the low-cost and processability of organic materials and, on the other hand, the chemical robustness, extreme thinness and flexibility of graphene.

Экспериментальное исследование СВЧ-пиролиза торфа

The work is devoted to the study of the destruction of the top sphagnum peat layer due to microwave radiation. For the analysis of physical and chemical processes, a laboratory setup was created on the basis of a coaxial resonator-reactor having a geometry that ensures a uniform distribution of the microwave field in the reactor volume. An industrial magnetron having a frequency of 2.45 GHz and a power of up to 1 kW was used as a source of microwave radiation. In laboratory studies with a relatively small amount of peat (~ 100 g), the advantage of the created setup consists in the ability to quickly achieve the necessary temperature for the pyrolysis reaction at a relatively low level of microwave power (~ 100 W) in these experiments. The analysis of the products obtained during the reaction was carried out using a gas chromatography mass spectrometer. The research was aimed at creating highly-efficient environmentallyfriendly technologies for processing biofuels characterised by a high yield of combustible gases suitable for further use in industrial power plants, as well as for obtaining a resinous fraction for the production of light hydrocarbons and a carbon residue for modern highly efficient sorbents. On the basis of the experimental setup, studies were carried out on soft microwave pyrolysis of peat at a temperature of 250 °C under constant removal of gaseous reaction products. Samples of solid, liquid and gas phases presenting valuable carbon residues, oily fractions and a pyrolysis gas, respectively, were obtained and analysed. The article examines the possibility for industrial application of reaction products. The chemical composition of the r eaction products during both microwave and “traditional” pyrolysis with thermal heating is compared. The composition of the gases released during microwave pyrolysis is characterised by the absence of heavy toxic gases often accompanying the process of “traditional” thermal pyrolysis. Reducing the amount of toxic gases improves the environmental component of production. This circumstance indicates the prospects of microwave pyrolysis for industrial processing of organic materials. The authors declare no conflict of interests regarding the publication of this article.

The hierarchical and perturbative forms of stochastic Schrödinger equations and their applications to carrier dynamics in organic materials

A number of non‐Markovian stochastic Schrödinger equations, ranging from the numerically exact hierarchical form toward a series of perturbative expressions sequentially presented in an ascending degrees of approximations are revisited in this short review, aiming at providing a systematic framework which is capable to connect different kinds of the wavefunction‐based approaches for an open system coupled to the harmonic bath. One can optimistically expect the extensive future applications of those non‐Markovian stochastic Schrödinger equations in large‐scale realistic complex systems, benefiting from their favorable scaling with respect to the system size, the stochastic nature which is extremely suitable for parallel computing, and many other distinctive advantages. In addition, we have presented a few examples showing the excitation energy transfer in the Fenna‐Matthews‐Olson complex, a quantitative measure of decoherence timescale of hot exciton, and the study of quantum interference effects upon the singlet fission processes in organic materials, since a deep understanding of both mechanisms is very important to explore the underlying microscopic processes and to provide novel design principles for highly efficient organic photovoltaics.This article is categorized under: Theoretical and Physical Chemistry > Reaction Dynamics and Kinetics Structure and Mechanism > Computational Materials Science

The aliphatic hydrocarbon distributions of terrestrial plants around an alpine lake: a pilot study from Lake Ximencuo, Eastern Qinghai-Tibet Plateau

As part of an investigation of the sources of aliphatic hydrocarbons to the sediments of alpine Lake Ximencuo, leaves of the eight dominant vascular plants were collected and their hydrocarbon contents were analyzed. A series of unsaturated aliphatic hydrocarbons were identified in the plant leaves; in particular, Festuca sp. contain a series of n-alkadienes that have rarely been reported in previous studies. The comparison of n-alkane proxies (ACL27–33, ACLT, Paq, and CPI) and δ13Corg among plant leaves, surface soils, and lake sediments suggests that organic proxies have been altered to varying degrees during the transport and burial process of organic materials. It is believed that microbial reworking and source changes have great impacts on organic proxies in the alpine lake system. In addition, the cluster analysis for plant leaves depending on n-alkane compositions and the ACLT proxy generates similar results. Accordingly, we postulate that the average chain length of plant waxes might be a potential indicator of plant classification in regions such as the Qinghai-Tibet Plateau.

PEMBUATAN KOMPOS CAIR DARI SAMPAH ORGANIK RUMAH TANGGA DI KM 13 PONDOK MEJA

Waste management can not only depend on the role of government, but also required public participation. Public awareness of the importance of waste management should begin to be grown. In addition to reducing the risk of environmental pollution, waste management aims to produce something more useful. Inorganic garbage can be managed with recycling technology that can produce a wide variety of useful items. Meanwhile, organic waste or organic waste can be managed and used as liquid compost. Technology applied to the manufacture of liquid compost that is by using a microorganism that can accelerate the decomposition process of organic materials. Thus, the waste management efforts into something more useful can be realized. Liquid compost is more effective and efficient when applied to the leaves, flowers and stems than the growing media (except in the hydroponic method). Liquid organic fertilizer can serve as a stimulus to grow. Especially when the plants begin to sprout or when the change from vegetative to generative phase to stimulate the growth of fruits and seeds. Leaves and stems can absorb fertilizers applied directly through the stomata or pores that exist on its surface.

Molecular Ion Formation by Photoinduced Electron Transfer at the Tetracyanoquinodimethane/Au(111) Interface

Optically induced processes in organic materials are essential for light harvesting, switching, and sensor technologies. Here we studied the electronic properties of the tetracyanoquinodimethane(TCNQ)/Au(111) interface by using two-photon photoemission spectroscopy. For this interface we demonstrated the lack of charge-transfer interactions, but we found a significant increase in the sample work function due to UV-light illumination, while the electronic structure of the TCNQ-derived states remain unaffected. Thereby the work function of the interface can be tuned over a wide range via the photon dose. We assigned this to a photoinduced metal-to-molecule electron transfer creating negative ions. The electrons are bound by a small potential barrier. Thus thermal activation reverses the process resulting in the original work function value. The presented photoinduced charge transfer at the TCNQ/Au(111) interface can be used for continuous work function tuning across the substrate's work function, which can be applied in device-adapted hole-injection layers or organic UV-light sensors.

IBM KELOMPOK TANI SAYURAN DI PATTAPANG

Veteran farmer groups and is a Veteran Youth vegetable farmer groups residing in the Village Pattapang, District High Muzzle, Gowa, South Sulawesi. Vegetables grown are cabbage, carrots, potatoes, onion leaves, cabbage, tomatoes, and squash. Land is located on land owned by farmers with a fairly steep slope so prone to erosion. Cultivation of vegetables is done conventionally by utilizing manure and inorganic fertilizer. Soil cultivation is done in the direction of the slope. Was based on the observance of watering, weed control, disease and pest control, but there has not been optimal production. Some of the problems encountered in the cultivation of vegetables is the magnitude and does not utilize organic materials in situ, where the organic material produced is burned. Implementation activities undertaken by the team Ipteks form of counseling, training, demonstration plots, and outreach. Materials science and technology as the solution of these problems is the processing of organic materials into bokhasi, conservation tillage, and cultivation of vegetables, especially potatoes technology. This activity received a positive response from members of farmer groups, due to significantly improve productivity and lower production costs. This becomes a strong motivation for participants to apply the knowledge and technology in sustainability efforts.

Earthworms as Organic Waste Managers and Biofertilizer Producers

Vermicomposting is the processing of organic materials by earthworms into homogeneous and humus-like material known as vermicompost. It is a complex mixture of fecal matter of earthworms and microorganisms. In vermicomposting system, earthworms act as voracious feeder, modifying composition of organic waste, gradually reducing its organic carbon and C:N ratio and retains more nutrients (nitrogen, potassium, phosphorus, calcium). The nutrient content is generally higher in vermicompost than in the traditional compost. Earthworm increases the surface area of any material and makes it more favorable for the activity of microbiota for further decomposition. Earthworms have the ability to consume various types of organic wastes such as livestock excreta, cattle dung, oil palm waste, agricultural residue, sewage sludge and other agro-industrial refuse. Studies suggested that organic wastes can be managed by the use of different species of earthworms and the production of vermicompost as a powerful biofertilizer in sustainable agriculture discouraging the use of chemical fertilizers. Vermicomposting accelerates the bioconversion process by two to five times as compared to traditional composting, thereby hastens the conversion of wastes into valuable biofertilizer. In the present review, earthworms are described as waste managers in utilizing and changing the physico-chemical properties of the organic wastes and highlight the need for the use of vermicomposting in organic waste recycling. Earthworm-microbe interaction and the nutrient status of final vermicompost are also discussed in detail.

Free fatty acids, tri-, di- and monoacylglycerol production and depth-related cycling in the Northeast Atlantic

We present the characterization and vertical distribution of suspended particulate lipids containing C, H and O which have the potential to sequester carbon from the upper ocean when associated with sinking particles. Lipids have been shown to be valuable in a host of environments to provide insights into the sources and processing of organic materials in the oceans. Here we present, direct-infusion, high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) combined with bulk lipid measures for marine lipid characterization. We present the water column distribution of free fatty acids, tri-, di- and monoacylglycerols from the surface layer to abyssopelagic depths (4800m) for samples collected in the Northeast Atlantic at the Porcupine Abyssal Plain sustained observatory (PAP-SO) (49.0°N, 16.5°W). Triacylglycerols (TG) with even carbon number (TG) and odd carbon number (oddTG, reflecting bacterial origin), were analyzed, while free fatty acids were analyzed as unsaturated (UFA), branched (BrFA) and saturated (SAFA) fatty acids. The surface productive layer (euphotic zone) was characterized with the highest incidence of lipids that are not reported in the Nature Lipidomics Gateway database, especially lipids that are highly unsaturated (acyl chain unsaturation was on average 3.8 for TG, oddTG, UFA and diacylglycerols (DG)). Additionally, we observed high lipid degradation at epipelagic depths. Fatty acid markers indicate that diatoms and dinoflagellates were important contributors to the lipid pool. Depth-resolved lipid change includes decreased lipid abundance and molecular diversity together with substantial loss of unsaturation with increasing depth. The major lipid change occurs at upper mesopelagic depths. Unlike other observed lipids, the abundance of SAFA remained essentially constant down the water column whereas the number of SAFAs and their contribution to total lipids increased with depth. Thus, we demonstrate that lipid saturation affects the export of carbon from the atmosphere to the deep ocean.

Thiol-ene-clickable and emissive carbazole-based polymer networks with tunable colors

Band gap tuning and processability of organic materials are significant topics for both scientific research and commercial applications. In this study, we synthesized a series of main chain cross-linkable polymers by thiol-ene click chemistry from N-allyl carbazole and different heterocycles via conventional Suzuki coupling polymerization reaction. The emission color of polymers could be successfully tuned from blue to red by attaching different benzazole-acceptor moieties to the carbazole donor unit. We also investigated the effects of cross-linking with respect to the amount of pentaerythritol tetrakis(3-mercaptopropionate) cross-linker on the optical, electrochemical, and surface morphological properties of the polymer films. The results showed that these polymers can be used as emissive active layers in solution-processable multilayer organic light-emitting diodes.

Growth, structure, and electronic properties in organic thin films deposited on metal surfaces investigated by low energy electron microscopy and photoelectron emission microscopy

We review the results of our achievements on thin film processes in organic materials obtained with the use of low energy electron microscopy (LEEM) and photoelectron emission microscopy (PEEM). We address the growth and the locally resolved electronic structure of an organic semiconductor, diindenoperylene, deposited on Au(100) and Au(111) single crystals, taking into account also the lattice geometry of the substrates. In addition, we present the results that we have obtained on a metal-free organic magnet, a derivative of the nitronyl nitroxide, grown on Si(111) surfaces. By taking great advantage of the LEEM and PEEM capabilities, our work has shown that it is possible to deeply understand which parameters influence the XPS spectroscopic lines in phenomena such as photoemission in organic materials. We have also elucidated with the simultaneous investigation of morphology, photoemission and absorption, the existing interplay between morphology, structure and electronic properties. The fact that the different modes of a LEEM–PEEM can be used to comprehensively investigate thin films in situ gives further relevance to the use of these microscopies, when describing fundamental chemical and physical phenomena at the interface and surface of materials.

The Effect of Surface Conditions on Diffusion and Permeability of Acetone through uPVC

Understanding diffusion and permeability processes in organic materials is important for applications to structural components, protective coatings or packaging. In this work some basic behaviour of solvent diffusion into and through a polymer are studied using acetone and un-plasticized polyvinyl chloride at room temperature as model materials. Special cell for gravimetric measurements is used to provide data on diffusion and permeability rates through samples of different thicknesses. It is shown that the rates of mass transport are slowing down with thickness for diffusion and also for permeability, as expected. However permeability mass transport is slower than mass delivered to the outer surface by diffusion. This is explained and experimentally verified by insufficient saturation of the surface layer, as the solvent evaporates before a full saturation is reached. When the outer surface layer is pre-saturated with solvent, permeability will increase several times. When evaporation is restricted (e.g. closed cavity) the liquid solvent will accumulate, filling up the cavity. Concentration profiles, measured by infrared microscopy, confirm this observation. It is suggested that the experimental data can be explained by using chemical potential and chemical reaction kinetics.

Museum factors affecting the ageing process of organic materials: review on experimental designs and the INVENVORG project as a pilot study

AbstractThe most common way followed for the determination of degradation mechanisms of organic materials is the application of physiochemical methods after accelerated aging. In recent years, there has been a remarkable research activity towards the development of alternative decay determination methods in organic materials based on statistics. We first present a survey of European research projects in this area together with summaries of their results. Second, we describe the ongoing project entitled ‘Investigation of the environmental factor effects on organic materials constituting the natural and cultural heritage’ in which statistics plays a crucial role. In particular, we present a statistical methodology that is based on a designed experimental and inferential protocol which will guide the research throughout the project. By providing basic statistical and design concepts, we present guidelines to design statistical protocols that are necessary for scientifically sound quantitative experiments.

Spacial and Temporal Variation of Degradation of Organic Matter by Benthic Macroinvertebrates

Leaf litter input from riparian landscapes has been identified as both a major energy flow to stream ecosystems and as a food source for stream macroinvertebrates. In this study the benthic macroinvertebrate community was used to evaluate the decomposition of organic matter in river systems. The aim of this work was to study the decomposition of organic matter using the benthic macroinvertebrate colonization. The research was developed over five months (January 2011 to May 2011) in four different sites, distributed along the River Ferreira terminal area, northern Portugal. A litter bag experiment was used to examine the role of macroinvertebrate communities in the processing of organic material on the river. Litter bags were placed in the water and collected every 7, 15, 30, 60, 90 and 120 days. In litter bags was observed a high abundance of Oligochaeta and Chironomidae, which are characterized by being detritivorous-herbivores and filtering collectors, respectively, indicating the benthic macroinvertebrate more involved on the decomposition of organic matter. These results contributed to increase current knowledge about benthic macroinvertebrate communities and may serve as incentive for future research works.

Probing Confinement Effects on Multilayered Ferroelectric Polymer Films Using Second Harmonic Generation

ABSTRACTElectrical energy storage plays a key role in mobile electronic devices, stationary power systems, and hybrid electrical vehicles. High energy density capacitors based on dielectric polymers are a focus of increasing research effort motivated by the possibility to realize compact and flexible energy storage devices, taking advantage of light weight and facile processability of organic materials. In addition, dielectric polymers enjoy inherent advantages of self-healing mechanism and high breakdown strength, leading to capacitors with great reliability and high energy density. It is the focus of this group to develop a multilayered ferroelectric PVDF system for improved energy storage efficiency. These systems are fabricated using enabling technology in co-extrusion which allows more cost effective and large area device production as opposed to more conventional layer-by-layer techniques. Many efforts have been made by the team to fabricate these micro- and nano-layered systems resulting in much improved device performance. A three-time improvement of capacitive electrical energy density has been demonstrated. The focus of this research is to understand the physics of why these multilayered systems perform better than a single layer by developing a characterization technique using both confocal second harmonic generation (SHG) and electric field induced second harmonic (EFISH) laser spectroscopy. Our results have shown that SHG is a very sensitive, non-destructive and versatile technique that can be used to study the ferroelectric and structural properties of layered systems. When combined with EFISH this technique allows the interrogation of structural and dielectric properties within the individual layers and at the interfaces between the layers. Further, the proposed techniques can be readily employed in-situ which can provide information in real time during sample processing with static and time-resolved spectroscopic measurements.

Seasonal Changes in Various Soil Organic Carbon Pools with Different Soil Amendments

In a sustainable agriculture farming systems experiment, the dynamics of soil organic carbon (OC), carbon/nitrogen (C/N) ratio and labile organic carbon pool in soil amended with maize stalk (MS), rice straw (RS) and alfalfa (AF) were studied from August 2005 to August 2006. The results showed that organic material with low N content decomposed slowly, while that with absolutely high N content depressed decomposition rate. After one year’s decomposition, the humification process of organic materials was basically complete. Soil labile carbon content was dramatically improved compared with the control after the addition of organic materials to the soil. The leached DOC was highly correlated with micro-organisms activity and MBC was highly dependent on N incorporation.