Additional Chemical Treatment Research Articles

Enhanced photoluminescence in grooved silicon microstructures

Grooved silicon structures formed by anisotropic chemical etching of crystalline silicon (c-Si) wafers in alkaline solution and composed by c-Si walls and voids (grooves) with thicknesses of several micrometers were found to exhibit efficient photoluminescence after excitation with laser radiation at 1.06 μm. The photoluminescence emission which originates from the interband radiative recombination of charge carriers in c-Si walls was represented by a broad spectral band centered at 1.1 eV. Independently on the polarization direction of the excitation light the photoluminescence of grooved silicon structures was partially linear-polarized with the polarization degree of 0.15–0.24 along c-Si walls and the photoluminescence intensity was strongly enhanced in comparison with that of c-Si substrate. These experimental observations are explained by considering an enhancement of the photoluminescence excitation due to both partial light localization in c-Si walls and a low rate of the non-radiative recombination at surface defects on c-Si walls. The defect density could be modified by additional chemical treatment or thermal annealing, which resulted in significant changes of the photoluminescence intensity of the grooved Si structures. The obtained results are discussed in view of possible applications of grooved Si in optoelectronics and molecular sensorics.

Fabrication of high aspect ratio nanostructures on 3D surfaces

A combination of different materials and processes was used to create high aspect ratio nanostructures on 3D surfaces. The high aspect ratio structures were formed on thermoplastic foils using UV-Nanoimprintlithography (UV-NIL) with a poly (dimethylsiloxane) (PDMS) stamp which was fabricated by soft lithography. An epoxy mixture with a higher glass transition temperature than the thermoplastic foil was used as a resist for UV-NIL. The hydrophobicity of structured substrates was characterized by the surface contact angle. Substrates with an additional chemical treatment were also produced and characterized. Results of contact angle measurement showed that superhydrophobic surface properties can be obtained with structured and chemically treated samples. The foils were further used as a substrate in a thermoforming process to transfer the structures into a microchannel. Using this process, 3D structured foils can be fabricated with high accuracy. The foils were used as a master structure for a replica molding process which allowed the fabrication of 3D structured polymer parts. With the presented method, microchannels with superhydrophobic surface properties can be fabricated.

A comparative study of microwave and chemically treated Acacia nilotica leaf as an eco friendly adsorbent for the removal of rhodamine B dye from aqueous solution

The use of cheap and eco friendly adsorbents prepared from freely and abundantly available Acacia nilotica leaves have been investigated by batch methods. Microwave treated A. nilotica leaves (MVM) are more effective than chemically treated A. nilotica leaves (CVM) for the removal of rhodamine B (RH B) from aqueous solution. The effect of initial pH, contact time and initial dye concentration of RH B onto CVM and MVM has been investigated. The applicability of the linear form of Langmuir model to CVM and MVM was proved by the high correlation coefficients R2=0.9413 and 0.9681 for RH B adsorption. The R2 values were greater than 0.994 for all RH B concentrations, which indicates the applicability of the pseudo-second-order kinetic model. The recycling ability of MVM is greater than CVM. The preparation of MVM does not require an additional chemical treatment step and it attains rapid equilibrium. Hence it is agreeing with the principles of green chemistry and less time is required to possess high adsorption of RH B. Therefore, the eco friendly adsorbent MVM is expected to be environmentally and economically feasible for the removal of RH B from aqueous solutions.

Replica molding for multilevel micro-/nanostructure replication

The development of micro- and nanofabrication processes with the capability to achieve three-dimensional structures is of great interest for a wide variety of applications. In this paper, a replica molding process for the replication of combined micro- and nanostructures in an epoxy-based photo resin is reported. First, multilevel masters were realized using standard micro- and nanofabrication processes. The structures from these masters were transferred to poly(dimethylsiloxane) (PDMS) stamps by soft lithography. Finally, the PDMS stamps were used for the replication of nano- and microstructures in the epoxy-based resin by UV casting. With this process, micro- and nanostructures of minimal dimensions of 50 nm were successfully replicated. Furthermore, the capabilities of the process were confirmed by the fabrication of a microfluidic device. In this system, the surface of micro channels was structured to modify its wetting properties and create hydrophobic and hydrophilic areas without any additional chemical treatment.

Thermally Cross-Linked PNVP Films As Antifouling Coatings for Biomedical Applications

Protein repellent coatings are widely applied to biomedical devices in order to reduce the nonspecific adhesion of plasma proteins, which can lead to failure of the device. Poly(N-vinylpyrrolidone) (PNVP) is a neutral, hydrophilic polymer with outstanding antifouling properties often used in these applications. In this paper, we characterize for the first time a cross-linking mechanism that spontaneously occurs in PNVP films upon thermal annealing. The degree of cross-linking of PNVP films and their solubility in water can be tailored by controlling the annealing, with no need for additional chemical treatment or irradiation. The physicochemical properties of the cross-linked films were investigated by X-ray photoelectron spectroscopy, infrared spectroscopy, neutron and X-ray reflectometry, ellipsometry, and atomic force microscopy, and a mechanism for the thermally induced cross-linking based on radical formation was proposed. The treated films are insoluble in water and robust upon immersion in harsh acid environment, and maintain the excellent protein-repellent properties of unmodified PNVP, as demonstrated by testing fibrinogen and immunoglobulin G adsorption with a quartz crystal microbalance. Thermal cross-linking of PNVP films could be exploited in a wide range of biotechnological applications to give antifouling properties to objects of any size, essentially making this an alternative to high-tech surface modification techniques.

Research of group and chemical composition of pyrocondensate and its products

Identity of physical-chemical properties of pyrocondensate with properties of oil-derived products is a reason of erroneous assumption about possible spheres of its application. For example, most spreaded application is like a substitution of heating oil or mazut, but petrol fraction (ab. 30 % of mass) makes this use risky. And some others characteristics don’t correspond to the norms of legacy standards on oil-derived products. That’s why direct using without any technological operations is impossible basing on the technological and ecological safety. Main reason of pyrocondensate incorrect use is connected with insufficient level of investigations and lack of independent and true data of laboratory tests. As far as most laboratory investigations on characteristics and properties of pyro-product are conducted without aim to obtain true information, as real (commercial) goal of similar tests contributes supraliminal limitation and restrict of results, which could be get without any commercial understanding of possibilities of realization. That’s why the receiving of independent results and conclusions is a first-priority task during study of possible spheres of safety and ecological friendly use of pyrocondensate. There were used few methods for laboratory tests, namely: method of accelerated liquid adsorption chromatograph to study a chemical composition of the product, method of infrared and mass-spectrometry to determine a group composition and method of gas fluid chromatograph to investigate a properties of fraction 38°−180° C, obtained at the atmospheric refraction of pyrocondensate. Detailed study of components chemical structure, which are contained in pyro-product, was conducts due to its separation on some narrow fractions by the method of liquid adsorption chromatography. On the base of results of laboratory tests there was established, that without additional chemical treatment and with minimum economics this product, obtained from scrap tires, can be use like a component for production of low-sulfur heating oil, low-viscous watercraft fuel or asphalt mixtures. Since pyro-condensate is a concentrate of olefins- naphthenes-aromatic hydrocarbons (approx. 94%), it can be use as a raw-material for production of high-quality fuels of naphthenes-parafins base. Method of atmospheric rectification allows obtaining a fraction of hydrocarbons with final boiling point 38–180° C (gasoline fraction), but because of high content of unsaturated hydrocarbon use only 10% of this fraction as a component for high-octane fuel. Generically pyrocondensate is a perspective component for substitution of traditional oil products and investigation of its properties is actual task on the way for looking of new sources of alternative energy-carriers.

Quantitative risk assessment of Cryptosporidium in tap water in Ireland

Cryptosporidium species are protozoan parasites associated with gastro-intestinal illness. Following a number of high profile outbreaks worldwide, it has emerged as a parasite of major public health concern. A quantitative Monte Carlo simulation model was developed to evaluate the annual risk of infection from Cryptosporidium in tap water in Ireland. The assessment considers the potential initial contamination levels in raw water, oocyst removal and decontamination events following various process stages, including coagulation/flocculation, sedimentation, filtration and disinfection. A number of scenarios were analysed to represent potential risks from public water supplies, group water schemes and private wells. Where surface water is used additional physical and chemical water treatment is important in terms of reducing the risk to consumers. The simulated annual risk of illness for immunocompetent individuals was below 1 × 10 − 4 per year (as set by the US EPA) except under extreme contamination events. The risk for immunocompromised individuals was 2–3 orders of magnitude greater for the scenarios analysed. The model indicates a reduced risk of infection from tap water that has undergone microfiltration, as this treatment is more robust in the event of high contamination loads. The sensitivity analysis highlighted the importance of watershed protection and the importance of adequate coagulation/flocculation in conventional treatment. The frequency of failure of the treatment process is the most important parameter influencing human risk in conventional treatment. The model developed in this study may be useful for local authorities, government agencies and other stakeholders to evaluate the likely risk of infection given some basic input data on source water and treatment processes used.

Exchange coupled pairs of dangling bond spins as a new type of paramagnetic defects in nanodiamonds

EPR in detonation nanodiamonds (DND) reveals two different signals associated with intrinsic carbon inherited paramagnetic defects. Main carbon inherited EPR signal is narrow intensive Lorentzian-like singlet with g=2.0028 and spin concentration Ns=(6−7)×1019 spin/g that yields on average 13–15 spins per each DND particle. Additional chemical treatment of DND powder allows practically complete removal of trace amounts of transition metal impurities that reveals a new doublet EPR signal consisting of two relatively narrow lines within the half-field region (g∼4) separated by a distance of 10.4 mT. The intensity of the doublet signal is five orders of magnitude lower than that of the main singlet signal. The former signal has been observed in a wide variety of DND samples disregarding of the impurity level reached and thus may be attributed to some intrinsic defects in DND particles. Such half-field EPR signals correspond to “forbidden” ΔMs=2 transitions within thermally populated triplet (S=1) levels observed in polycrystalline samples containing exchange dimers—antiferromagnetically coupled spin pairs. Estimates suggest that the concentration of such defects is about one dimer per hundreds DND particles.

Optimization of Artificial Activation in Porcine Embryos Using Short-Term Treatment of 6-DMAP and Demecolcine.

It is known that post treatment of 6-dimethylaminopurine (6-DMAP) or demecolcine (DE) for several hours (at least two hours) after electric activation improves in vitro development of porcine embryos. However, several reports also have shown that the additional chemical treatment induces apoptosis in treated embryos. Thus, this study was carried out to optimize activation condition using short-term treatment of 6-DMAP and DE to reduce detrimental effect of the chemical treatment. Experiment 1 was performed to find out whether short term treatment is valid as much as long term treatment. As 6-DMAP (2mM) and DE (0.4 μg/ml) were generally treated for 3 hr, we set 3 hr exposure as long-term treatment and 40 min as short-term treatment. For artificial activation, electric pulse (EP; a single DC pulse of 1.5 kV/ cm for 60 μsec) or chemical activation (T/D; 0.2 mM thimerosal for 10 min + 8 mM dithiothrethiol for 30 min) was used. As a result, there is no significant difference in cleavage and blastocyst formation rates between long term and short term treatment in both electric and chemical activation groups. Therefore, experiment 2 was conducted to investigate optimal condition of short term treatment of 6-DMAP and DE (ST). Matured oocytes were subjected on three following activation protocols; 1) EP + ST, 2) T/D + ST, 3) EP+ T/D + ST. As a result, T/D + ST induced most effective activation compared to EP + ST and EP+ T/D + ST groups: higher cleavage rate (73.7 vs. 68.0, 69.9%, P<0.05), higher BL formation rate (30.0 vs. 13.6, 20.2%, P<0.05) and more total cell number of BL (45.6 vs. 39.5, 36.0, P<0.05). In conclusion, short term treatment of 6-DMAP and demecolcine can lead efficient activation and is optimal in combination with chemical activation using T/D. This research was supported by BK21, KOSEF (#M10625030005-08N250300510), HANWHA L&C Corp, and Gyeonggido Veterinary Service. (platform)

Two‐ and three‐dimensional profilometer assessments to determine titanium roughness

In this study, a comparative topography analysis of titanium (Ti) surfaces was performed using two- (2D) and three-dimensional (3D) profilometers. Ti samples were either only sandblasted (SB) using Al(2)O(3) particles or were SB and received an additional chemical treatment using a solution of 4% HF (SLA). Samples with no treatment were used as a control group (C). Therefore, three different surfaces were evaluated: SB, SLA and C. The Ti surface topographies were evaluated by scanning electron microscopy. An Ra roughness measurement was performed on each Ti sample by 2D and 3D profilometers. Surface roughness was also characterized using amplitude, spatial and hybrid 3D parameters. 2D and 3D profilometer analyses produced very close results. Mean Ra values range from 0.19 to 0.25 (C, p<0.05), 0.84 to 0.99 (SLA, p<0.05) and 0.98 to 1 microm (SB, p>0.05). The statistically different Ra values depending on the surface studied may be explained by methodological and technical differences. Also, 3D profilometer seems to be the more appropriate analytical method for measuring the roughness of Ti surfaces because it also describes surface organization.

Sorption characteristics of pesticides on matrix substrates used in biopurification systems

On-farm biopurification systems were developed to remove pesticides from contaminated water generated at the farmyard. An important process in the system’s efficiency is the sorption of pesticides to the substrates used in the biopurification systems. The composition and type of material present in the biobed are crucial for retention of chemicals. This study investigated the sorption of linuron, isoproturon, metalaxyl, isoxaben, bentazon and lenacil on substrates commonly used in a biopurification system, i.e. cow manure, straw, willow chopping, soil, coconut chips, garden waste compost, and peat mix. Linear, Freundlich, and Langmuir sorption isotherms were fitted to the obtained data. The best fit was obtained with the Freundlich model. More immobile pesticides (i.e. linuron and isoxaben) tended to associate with the organic substrate, while more mobile pesticides partition in the water (i.e. bentazon). According to sorption capacity, the substrates could be classified as peat mix > compost, coco chips, straw > cow manure, willow chopping > sandy loam soil. Sorption capacity was positively correlated with the organic carbon content, CaO and the cation exchange capacity. Furthermore, no significant differences in sorption could be found between technical and formulated isoproturon and bentazon. Moreover, the individual sorption coefficient K d was additive, which means that individual sorption coefficients can be used to calculate the sorption coefficients of a mixture of substrates. What concerns the mutual interaction of pesticides it could be observed that the sorption of linuron and metalaxyl was significantly lower in combination with isoproturon and bentazon, while the latter pesticides were not influenced by the presence of linuron and metalaxyl. As guidelines, firstly, it could be stated that using the most sorbing materials such as peat mix, might significantly increase the biopurification systems efficiency. Secondly, the treatment of very mobile pesticides, such as bentazon, should be taken with care as these will easily leach through the system. Additional chemical treatment might be necessary for these type of pesticides.

Copper biosorption from aqueous solutions by sour orange residue

In this study, copper uptake by sour orange residue (SOR) was investigated. Equilibrium isotherms and kinetics were obtained and the effects of solution pH, temperature, and particle size were studied in batch experiments. Equilibrium was well described by Langmuir and Freundlich isotherms and kinetics was found to be best-fit pseudo-second order equations. Maximum uptake was observed at pH 5. With an increase in temperature from 20 to 50 °C, copper removal decreased about 20%. Additional chemical treatment of the biosorbent by NaOH, increased the biosorption capacity. It was found that increase in biosorbent particle size had no significant effects on the final equilibrium concentration, but decreased biosorption rate.

A new polymeric silicone hydrogel for medical applications: synthesis and properties

AbstractA novel silicone hydrogel polymeric material is developed. The preparation method is based on sequential interpenetrating network synthesis. A silicone network is obtained by the interaction between two siloxane oligomers comprising hydride and vinyl functional groups. A hydrophilic network is prepared by radical copolymerization of hydrophilic monomers (N‐vinyl pyrrolidone, N,N‐dimethylacrylamide) and crosslinking agent (ethylene glycol dimethacrylate). In the hydrated state the developed material has high mechanical properties, transparency, hydrophilicity, oxygen and water permeability. The developed new technology affords obtaining a silicone hydrogel material with a good wettability without additional chemical or plasma surface treatment. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Elastic and inelastic properties of SiC/Si biomorphic composites and biomorphic SiC based on oak and eucalyptus

This paper reports on the results of a comparative investigation into the elastic and microplastic properties of biomorphic SiC/Si composites and biomorphic SiC prepared by pyrolysis of oak and eucalyptus with subsequent infiltration of molten silicon into a carbon matrix and additional chemical treatment to remove excess silicon. The acoustic studies were performed by the composite oscillator technique using resonant longitudinal vibrations at frequencies of about 100 kHz. It is shown that, in biomorphic SiC (as in biomorphic SiC/Si) at small-amplitude strains e, adsorption and desorption of the environmental (air) molecules determine to a considerable extent the Young’s modulus E and the internal friction (decrement of acoustic vibrations δ) and that the changes in E and δ at these amplitudes are irreversible. The stress-microplastic strain curves are constructed from the acoustic data for the materials under study at temperatures of 100 and 290 K.

THE LOADS OF PAHS IN WASTEWATER AND SEWAGE SLUDGE OF MUNICIPAL TREATMENT PLANT

Sewage and sewage sludge from a municipal wastewater treatment plant were analyzed for 16 EPA-PAHs. This plant is a classic mechanical-biological treatment plant, consisting of activated sludge technology with additional chemical treatment for the removal of phosphorus compounds. The process of sewage sludge treatment is carried out in closed as well as open sludge digesters. Primary and mechanically thickened sludge are passed through the fermentation process. Digested sludge is dewatered on filter-press through addition of flocculent. The measurements were obtained to investigate the effect of different treatment stages on PAH content in wastewater and sewage sludge. The following wastewater samples were collected: crude ones and those after sand trap, primary sedimentation, biological treatment and secondary sedimentation. Sewage sludge samples were collected from: primary sludge, digested sludge and dewatered sludge. PAH load in influent, mechanically and biologically treated sewage, as well as in raw digested and dewatered sludge, were calculated. PAHs were extracted from wastewater and sludge samples, with cyclohexane, dichloromethane using an ultrasonic method. Gas chromatograph equipped with mass spectrometry was used for qualitative and quantitative determination of PAHs. Mechanical and biological treatment proved the removal of 83–85% of PAHs from the influent. Despite this its daily PAH load introduced into the environment was high and reached 27–37% of PAH load in influent. In sewage sludge it was 46–70 g/d of PAHs (carcinogenic PAHs content 4–12%). In waste sludge (filter pressed sludge and sand from detrirer) PAH total load reached 42–68 g/d with (10–17% of carcinogenic PAHs).

Natural polysaccharides and their interactions with dye molecules: applications in effluent treatment.

Dyeing effluent is one of the largest contributors to textile effluent and such colored wastewater has a seriously destructive impact on the environment. Adsorption can be a very effective treatment for decolorization of textile dyeing effluent, but current techniques employ adsorption chemistry that is not particularly environmentally friendly, such as the use of alum. In this study, natural polysaccharides were used as adsorbents for removal of dye molecules from effluent. The results showed that naturally cationic polysaccharides such as chitin and chitosan gave excellent levels of color removal, and this was attributed to a combination of electrostatic attraction, van der Waals forces, and hydrogen bonding. Nonionic galactomannans (locust bean gum, guar gum, cassia gum) were also highly effective in removing dye from effluent, whereas other nonionic polysaccharides, such as starch, were not effective. This was attributed to the structure of the polysaccharides and the relative degree of inter- and intramolecular interactions between separate polymer chains. The pendant galactose residues of galactomannans prevented strong interaction, allowing greater hydrogen bonding with dye; comparatively, starch has extensive chain interactions, and as such had limited potential for hydrogen bonding with the dye molecules at the temperature of application. In addition, hydrophobic interactions between the hydrophobic parts of the dye and the alpha-face of the pendant galactose residues may have contributed to the superior performance. Repulsion between anionic polysaccharides and the dye anions prevented any hydrogen bonding and as such pectin, carrageenans, and alginic acid were not effective in dye removal from effluent. The use of galactomannans derived from plants in this system presents a sustainable method of effluent treatment. The raw materials are derived from renewable plant sources and are available in tonnage quantities, the adsorption system itself is highly effective and does not involve any additional chemical input or treatment other than the use of the adsorbent, and the adsorption agents themselves are nontoxic and biodegradable.

Induction mechanism of 3-hydroxy-3-methylglutaryl-CoA reductase in potato tuber and sweet potato root tissues.

3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR, EC1.1.1.34), the key enzyme in isoprenoid biosynthesis, was purified from microsomes of potato tuber tissue, and a polyclonal antibody and two monoclonal antibodies against the purified enzyme were prepared. HMGR protein content was measured by immunotitration and radioimmunoassay using these antibodies. HMGR activity was very low in the fresh tissues of both potato tuber and sweet potato root. The activity in potato tuber was increased by cutting and further by additional fungal infection of the cut tissues. In sweet potato root tissue, the activity was scarcely increased after cutting alone, but was markedly increased by additional fungal infection or chemical treatment. The HMGR protein contents in both fresh potato tuber and sweet potato root tissues were also very low, and increased markedly in response to cutting and fungal infection. From these results, we proposed a hypothesis on the induction mechanism of HMGR after cutting and fungal infection in potato tuber and sweet potato root tissues.

PIXE Analysis of Trace Heavy-Metals in River Waters Using an Ion-Exchange Cellulose Filter Paper

A simple but precise method for the PIXE analysis of trace heavy-metals in aqueous samples was developed, in which the PIXE targets were prepared by pre-concentrating heavy metals on a cellulose phosphate ion-exchange filter paper and no additional chemical treatment was required. Heavy metals in trace concentrations were quantitatively retained up to 16.7 μ-equivalent on a sheet of filter paper due to the excellent selectivity for heavy metals and ion-exchange kinetics of phosphate groups in cellulose matrix. Heavy metals of less than 1 μg on one filter paper are precisely and rapidly determined by PIXE analysis using 3-MeV proton beams. The present method is compared with the method preparing a PIXE target for each dissolved species of an element contained in aqueous samples. It will be resulted that the newly developed method enables an on-line PIXE analysis for river waters.

Geology and Characterization of Two Hydrothermal Nontronites from Weathered Metamorphic Rocks at the Uley Graphite Mine, South Australia

AbstractMining operations during the early 1990s at Uley Graphite Mine near Port Lincoln on southern Eyre Peninsula, South Australia, uncovered abundant nontronite veins in deeply weathered granulite facies schist, gneiss, and amphibolite of Palaeoproterozoic age. Two types of nontronite are present: a bright yellowish-green clay (NAu-1) distributed as veinlets and diffuse alteration zones within kaolinized schist and gneiss, and a massive to earthy, dark-brown clay (NAu-2) infilling fracture networks mainly in amphibolite or basic granulite. The nontronites are the product of low-temperature hydrothermal alteration of primary minerals, biotite, and amphibole. The principal chemical difference between NAu-1 and NAu-2 is a higher alumina content in NAu-1, which was either inherited during hydrothermal alteration of biotite in the host rock or acquired through recrystallization of nontronite during subsequent weathering and associated kaolinization. Sufficient bulk samples of both NAu-1 and NAu-2 were collected to supplement reference nontronite of the Source Clay Repository of The Clay Minerals Society. The clay fraction of the bulk samples is typically &gt;85%. NAu-1 contains minor kaolin and quartz which are easily removed to give a high purity nontronite of composition M+1.05[Si6.98Al1.02][Al0.29Fe3.68Mg0.04]O20(OH)4, similar to that of nontronite from Garfield, Washington. NAu-2 contains fewer total impurities but the presence of trace amounts of submicron carbonate and iron oxyhydroxide requires additional chemical treatment to produce a nontronite of purity comparable to NAu-1. Composition of NAu-2 was calculated as M+0.72[Si7.55Al0.45][Fe3.83Mg0.05]O20(OH)4, although infrared data indicate that at least some Fe is in tetrahedral coordination.

Physical structure of polyolefin−starch blends after ageing

Low density polyethylene- or polypropylene–starch blends containing 40–50 wt% of glycerol plasticized starch were subjected to four months long soil test, and then they were etched with 10% aqueous natrium hydroxide solution during 5 days at room temperature. On every stage of degradation the supermolecular structure of blends was investigated by means of SAXS and WAXS methods. It was found that during biodegradation in soil ca. 75% of the initial starch phase content was removed from blends. Further decrease of the starch phase content up to 80–85% was observed after chemical degradation in NaOH solution. The WAXS measurements have shown that biodegradation in soil does not affect significantly the crystalline phase content in polyethylene (45%) or polypropylene (55%). However, the additional chemical treatment of polyolefin-starch blends with NaOH solution leads to some increase of the crystallinity index both for polyethylene (48%) and polypropylene (65%). The SAXS measurements indicated the heterogenity changes in blends after the degradation processes on larger spatial length than the long period in semicrystalline polyethylene or polypropylene. These changes can affect the mechanical behaviour of blends, e.g. an increase of elongation at break, observed after the degradation tests.