Paraffin Layer Research Articles

Magnetic properties of monodisperse nanomagnetite

The monodisperse magnetite nanoclusters 13–15 nm in size were synthesized and studied. The nanoclusters were stabilized in colloid solution by means of surface-active-substance (SAS)—oleic acid in the presence, paraffin—docosane and separated from each other by paraffin layers at the distance approximately ∼3 nm. The first order magnetic phase transition was observed in magnetite, when magnetization of a cluster disappears by jump at some critical temperature similar to that of the Curie or Neel temperatures typical of the bulk material. The observed effect is explained by the influence of surface-induced defects in the nanomagnetite. The developed surface of a cluster generates defects and causes surface tension. The model is proposed, and transition from a paramagnetic to magnetic ordered (superparamagnetic) state of a cluster is found experimentally by applying an external magnetic field which is more than some critical one. Nanomagnetite itself exists in a special “oxidized condition”, which elementary cell is the same as in normal magnetite, but it contains only trivalent cations in a B-sublattice.

Stabilization and Solidification of Elemental Mercury for Safe Disposal and/or Long-Term Storage

ABSTRACT A simple and highly effective stabilization/solidification (S/S) technology of elemental mercury using only sulfur with paraffin is introduced. First, elemental mercury is mixed with an excess of sulfur powder and heated to 60 °C for 30 min until elemental mercury is converted into mercuric sulfide (HgS black, metacinnabar) (Step 1). Then, metacinnabar with additional sulfur is poured into liquid paraffin (Step 2). Finally, the mixture is melted at 140 °C and settles to the bottom of the vessel where it cools and solidifies under the layer of liquid paraffin (Step 3). The proposed S/S method with sodium sulfide nonahydrate (Na2S·9H2O) as an additive is also tested for comparison. The average toxicity characteristic leaching procedure test values are 6.72 μg/L (no additive) and 3.18 μg/L (with additive). Theses concentrations are well below the Universal Treatment Standard (25 μg/L). Effective diffusion coefficient evaluated from accelerated leach test and average headspace concentration of Hg vapor after 18 hr are 3.62 × 10−15 cm2/sec, 0.55 mg/m3 (no additive) and 5.86 × 10−13 cm2/sec, 0.25 mg/m3 (with additive). IMPLICATIONS The simple treatment method for elemental mercury by stabilization/solidification introduced in this study will benefit the United Nations Environmental Programme (UNEP) Mercury Programme initiating a project to reduce the global mercury supply and address the safe and long-term storage of mercury. In addition, it will also provide an option and possible solution to the compliance of the recently passed law individually by the European Union and the United States banning the sale of toxic mercury abroad in 2011 and 2013, respectively.

Air-stability analysis and improvement of poly(3-hexylthiophene) field-effect transistors

The influence of air, dry oxygen and humidity on the performance of a top-contact polymer field-effect transistor using poly(3-hexylthiophene) (P3HT) as an active layer is investigated. It is demonstrated that high relative humidity (92%) causes the device to degrade rapidly, while the influence of dry oxygen on the device is relatively small, indicating that the harmful influences are mainly the result of atmospheric water due to the enhancement of carrier conduction in the vicinity of the active-layer surface caused by the absorption of water molecules on the surface, rather than the p-type doping effect of O2. A photoresist or paraffin layer is utilized as a passivation layer on top of the P3HT film, and the effects of the passivation layer on the performance and stability of the device are investigated. Results indicate that the passivation layer can effectively improve the stability of the device exposed to air, and enhance its field-effect mobility.

Physiological bicarbonate buffers: stabilisation and use as dissolution media for modified release systems

Bicarbonate media are reflective of the ionic composition and buffer capacity of small intestinal luminal fluids. Here we investigate methods to stabilise bicarbonate buffers which can be readily applied to USP-II dissolution apparatus. The in vitro drug release behaviour of three enteric coated mesalazine (mesalamine) products is investigated. Asacol ® 400 mg and Asacol ® 800 mg (Asacol ® HD) and the new generation, high dose (1200 mg) delayed and sustained release formulation, Mezavant ® (Lialda ®), are compared in pH 7.4 Krebs bicarbonate and phosphate buffers. Bicarbonate stabilisation was achieved by: continuous sparging of the medium with 5% CO 2(g), application of a layer of liquid paraffin above the medium, or a specially designed in-house seal device that prevents CO 2(g) loss. Each of the products displayed a delayed onset of drug release in physiological bicarbonate media compared to phosphate buffer. Moreover, Mezavant ® displayed a zero-order, sustained release profile in phosphate buffer; in bicarbonate media, however, this slow drug release was no longer apparent and a profile similar to that of Asacol ® 400 mg was observed. These similar release patterns of Asacol ® 400 mg and Mezavant ® displayed in bicarbonate media are in agreement with their pharmacokinetic profiles in humans. Bicarbonate media provide a better prediction of the in vivo behaviour of the mesalazine preparations investigated.

Melting of short-chain polymers

The melting of paraffin layers is investigated in terms of the two-dimensional dislocation theory of melting. The theory is strictly applicable to short paraffin chains. For longer chains the melting criterion is modified to include the reduction of melting point due to chain flexibility (kinking). The results are found to be in satisfactory agreement with experiment.

A Novel MALDI Matrix for Analyzing Peptides and Proteins: Paraffin Wax Immobilized Matrix

AbstractA new kind of MALDI matrix, termed paraffin wax immobilized matrix, was used to study peptide mixtures and proteins. During the preparation process, the paraffin wax was heated and coated on the stainless‐steel target plate, and then 2,5‐dihydrobenzoic acid (DHB) was deposited on the paraffin layer and stainless‐steel target plate to obtain different kinds of matrix spots. The morphology of matrices on different supports and peptide‐matrix co‐crystallization were observed by a high resolution digital‐video microscopy system. Peptide mixtures and bovine serum albumin (BSA) digests were used to investigate the performance of the immobilized matrices on the paraffin target. The MALDI‐FTMS analysis results also showed that the detection sensitivity of matrices immobilized in the paraffin sample support was better than that on other sample supports.

Engineering and validation of a novel lipid thin film for biomembrane modeling in lipophilicity determination of drugs and xenobiotics

BackgroundDetermination of lipophilicity as a tool for predicting pharmacokinetic molecular behavior is limited by the predictive power of available experimental models of the biomembrane. There is current interest, therefore, in models that accurately simulate the biomembrane structure and function. A novel bio-device; a lipid thin film, was engineered as an alternative approach to the previous use of hydrocarbon thin films in biomembrane modeling.ResultsRetention behavior of four structurally diverse model compounds; 4-amino-3,5-dinitrobenzoic acid (ADBA), naproxen (NPX), nabumetone (NBT) and halofantrine (HF), representing 4 broad classes of varying molecular polarities and aqueous solubility behavior, was investigated on the lipid film, liquid paraffin, and octadecylsilane layers. Computational, thermodynamic and image analysis confirms the peculiar amphiphilic configuration of the lipid film. Effect of solute-type, layer-type and variables interactions on retention behavior was delineated by 2-way analysis of variance (ANOVA) and quantitative structure property relationships (QSPR). Validation of the lipid film was implemented by statistical correlation of a unique chromatographic metric with Log P (octanol/water) and several calculated molecular descriptors of bulk and solubility properties.ConclusionThe lipid film signifies a biomimetic artificial biological interface capable of both hydrophobic and specific electrostatic interactions. It captures the hydrophilic-lipophilic balance (HLB) in the determination of lipophilicity of molecules unlike the pure hydrocarbon film of the prior art. The potentials and performance of the bio-device gives the promise of its utility as a predictive analytic tool for early-stage drug discovery science.

Toward a Direct Measurement of Paraffin Adhesion Forces

In the present work, the interaction forces between paraffin surfaces and solid substrates were studied using an atomic force microscope (AFM). Approximation and retraction curves, called force curves, were measured at room temperature between the AFM probe and stainless-steel (SS) substrates with either of them uncoated or coated with a paraffin film. A great influence of the surface topography on the force curves was observed. This influence results in a large variation of the interaction force values obtained at different spots of the sample surface. For some of the spots, which are associated with large paraffin crystals or agglomerates, the force curves change each time a measurement is performed, apparently because of the deformation of the paraffin crystal. For some other spots, which seem to be related to thin paraffin layers, a reproducible behavior is observed, allowing for the estimation of the interaction force values. A considerable dispersion of the values of adhesion forces and jump-in and ...

An electrochemical impedance spectroscopy study of copper in a bentonite/saline groundwater environment

Pure copper samples have been exposed for 6 years in a bentonite test parcel in the Äspö Hard Rock Laboratory, which offers a realistic environment for the conditions that will prevail in a deep repository for high-level radioactive waste disposal in Sweden. After retrieval of the test parcel, a bentonite test package containing the samples was placed in a container and sealed with a thick layer of paraffin, and later on new copper and platinum samples were installed. An electrochemical impedance spectroscopy study has been performed on the pre-exposed and new copper samples for different durations in the retrieved test package. The impedance spectra for copper in the bentonite/saline groundwater environment change considerably with time of exposure. The change is more pronounced at higher than at lower frequencies. It is presumed that the corrosion resistance of pure copper in this environment mainly depends on a thin protective cuprite film that forms readily, and on a thick porous outer corrosion product layer (mainly cuprite) that develops slowly and partly intermixes with the bentonite. The impedance data revealed that both the inner and the outer corrosion product layer were involved in the impairment and the recovery of the corrosion resistance when the copper interface was disturbed during retrieval of the bentonite test package.

Relationship between Deep Root Distribution and Root Penetration Capacity Estimated by Pot Experiments with a Paraffin and Vaseline Layer for Landraces and Recent Cultivars of Wheat

Root growth into deep soil is an important factor for stable production in wheat under drought conditions. Root penetrating capacity (RP) shown by pot experiments with a paraffin-Vaseline layer (PV layer) may be a useful indicator estimating deep rooting ability of wheat genotypes. Previously, we identified genotypes of durum wheat (Triticum turgidum L. var. durum) and bread wheat (T. aestivum L.) with diverse RP by the pot experiments. In this study, we investigated the root distribution of three Ethiopian landraces of durum wheat with high RP, three recent cultivars of durum wheat with low RP and one Japanese cultivar of bread wheat ‘Haruyutaka’ with low RP using: (1) pots with a PV layer, (2) root boxes, (3) artificial field and (4) a normal field to analyze the relationship between RP estimated by pot experiment and root development in the field. In the pot experiments, RP was evaluated by the number of roots penetrating through the PV layer (NRP). In the root-box and field experiments, the root distribution was evaluated by the number of roots on the vertical surface of soil as the root frequency (RF: root number cm-1 soil surface). Ethiopian landraces had a significantly larger NRP than recent cultivars in the pot experiment. The root box and field experiments showed that Ethiopian landraces tended to have a higher RF than recent cultivars in deep soil layer. We concluded that RP estimated by pot experiments with a PV layer is a useful indicator of deep rooting ability under field conditions.

Nonanoic acid, other alkanoic acids, and related compounds as antifeedants in Hylobius abietis pine weevils

AbstractA medium‐length, straight‐chain alkanoic acid, nonanoic acid, is known from laboratory microassays to be an antifeedant in adults of the large pine weevil, Hylobius abietis (L.) (Coleoptera: Curculionidae). Our hypothesis was that we could find new, less volatile alkanoic acids or related compounds suitable for field application and with improved long‐term duration. Alkanoic acids of varying chain lengths (C6–C13) were tested for antifeedant activity in H. abietis adults. Microassay choice tests showed that straight‐chain (C6–C11) alkanoic acids were active. However, high activities were restricted to the (C6–C10) acids, with the C9 (nonanoic acid) at 4 µmol cm−2 being the most active one. In a no‐choice test on pine twigs, the antifeedant effect of C10 acid was lower than that of the C8 and C9 acids. In microassays, less volatile methyl‐branched alkanoic acids exhibited lower antifeedant activities than did the corresponding straight‐chain ones. However, the most active of the methyl‐branched acids, 2‐methyldecanoic acid, had an activity similar to that of nonanoic acid. Compounds related to nonanoic acid were either active (1‐nonanol), weakly active (nonanoic anhydride), or inactive (nonanal, sodium nonanoate). The anhydride was highly active in the microassay, but less active on twigs. The antifeedant effects of the straight chain (C8–C10) alkanoic acids against pine weevil feeding were tested in the field. In contrast to the results from the twig tests, the less volatile C10 acid was more active in the field for the protection of transplants on fresh clear cuts over a 3‐month period than both the C8 and C9 acids. Phytotoxic effects of the alkanoic acids were observed both in the field and in laboratory studies. If a protective layer of paraffin was applied to the stem prior to application of the alkanoic acids, these undesired side effects were reduced.

A solder sealing method for paraffin-filled microcavities

Demonstrated and investigated here is a method to seal microfluidic systems by soldering. As a particularly difficult case of growing importance, the sealing of openings contaminated with paraffin wax was studied. Solder paste, screen printed on a metallized silicon substrate, was melted locally through application of 6.5–10 V to a 5 Ω copper film resistor for a few seconds and was found able to drive an intermediate layer of paraffin away and seal a 0.2 mm diameter circular via by wetting a surrounding copper pad. Although verified to be robust, the process did result in failing seals on excessive heating because of consumption of the pads. Correctly performed, the technique provided a seal at least withstanding a pressure of 8 bar for 8 h at 85 °C.

Thermally induced gelable polymer networks for living cell encapsulation

We report the encapsulation of MIN6 cells, a pancreatic beta-cell line, using thermally induced gelable materials. This strategy uses aqueous solvent and mild temperatures during encapsulation, thereby minimizing adverse effects on cell function and viability. Using a 2:1 mixture of PNIPAAm-PEG-PNIPAAm tri-block copolymer and PNIPAAm homopolymer that exhibit reversible sol-to-gel transition at approximately 30 degrees C, gels were formed that exhibit mechanical integrity, and are stable in H(2)O, PBS and complete DMEM with negligible mass loss at 37 degrees C for 60 days. MTT assays showed undetectable cytotoxicity of the polymers towards MIN6 cells. A simple microencapsulation process was developed using vertical co-extrusion and a 37 degrees C capsule collection bath containing a paraffin layer above DMEM. Spherical capsules with diameters ranging from 500 to 900 microm were formed. SEM images of freeze-dried capsules with PBS as the core solution showed homogenous gel capsule membranes. Confocal microscopy revealed that the encapsulated cells tended to form small aggregates over 5 days, and staining for live and dead cells showed high viability post-encapsulation. A static glucose challenge with day-5 cultured microencapsulated cells exhibited glucose-dependent insulin secretion comparable to controls of free MIN6 cells grown in monolayers. These results demonstrate the potential use of these thermo-responsive polymers as cell encapsulation membranes.

구동력과 가스 제공을 위한 이산화탄소 발생기

This paper presents a novel microgenerator of CO₂(carbon dioxide) gas. NaHCO₃(sodium bicarbonate) in a chamber is decomposed by the underlaid microheater. Alternatively, water droplet is caged by paraffin layer and released by heating. The released water dissolve HOC(COOH)(CH₂COOH)₂(citric acid) powder and then. NaHCO₃ reacts with the solubilized HOC(COOH)(CH₂COOH)₂ and CO₂ is produced. Micropumps actuated by CO₂ generation were fabricated. A portable micro cell incubator of which pH is controlled by the produced CO₂ is also presented as one of the further applications.

The Hg—P (Mercury—Phosphorus) System

AbstractFor Abstract see ChemInform Abstract in Full Text.

The phase transitions of n-alkanes in mesoscopic pores of graphite

The phase transitions of two n-alkanes of different parity, C 16H 34 and C 17H 36, confined in the mesoscopic pores of exfoliated graphite have been studied by differential scanning calorimetry. For samples from one statistical monolayer up to about four layers of paraffin, microcalorimetry shows a characteristic signature from the “surface phase” alone. At higher fillings the melting and phase transition temperatures and enthalpies of the additional “included” phase were depressed compared to those of the bulk paraffin. The depressions in the phase transition temperatures and the neperian logarithm of the enthalpies are to a good approximation inversely proportional to the number of included layers. Depending on the coverage, competing effects between the graphite surface and the degree of filling of the pores are observed for both the surface phase and the included phase. The results for the included phase are consistent with the Gibbs–Thompson equation down to pore sizes of the order of a few nanometres.

The Hg-P (Mercury-Phosphorus) System

The Hg-P system was not studied systematically, and its whole phase diagram is unknown. Hg and P (white) melt at –38.8290 and 44.14 °C, respectively, and boil at 356.623 and 277 °C, respectively, when the pressure is 0.101325 MPa. P exists in many allotropic modifications [1989Gre]. At least five crystalline and several amorphous or vitreous forms of P are known, but when they melt, they all give the same liquid, consisting of P4 molecules of tetrahedral structure. This form is also present in the gas phase at temperatures lower than 800 °C. The allotropic forms of P have different colors and other physical properties as well as different chemical reactivities. The most stable allotropes are cubic P (white) and orthorhombic phosphorus (black). It is of interest that P heated at 380 °C in the presence of Hg gives vitreous gray P [1989Gre]. [1911Vou] claimed the formation of a Hg-P compound by heating both components under a layer of paraffin, but no analysis was made to determine the resultant product. Hg 3 P 4 ,H g 3 P 2 , and Hg 3 P compounds were obtained by indirect chemical reactions [1947Mel], but formation by direct alloying was not observed by [1951Rot]. Therefore, these compounds should be treated as metastable phases. The melting temperatures of P and Hg would suggest considerable miscibility of the elements near ambient temperature. According to [1910Ger], molten P dissolves some amount of Hg, and the resulting colorless solution is blackened after solidification due to the rejection of Hg excess. [1951Rot] measured Hg solubility in metastable liquid P at 25 °C by using a chemical analysis of the equilibrated phases. The solubility value found amounts to 0.0176 at.% Hg, which amounts to one-fifteenth of the value predicted from the regular solution model. These authors observed that the solubility of Hg in liquid P increased slightly with temperatures up to 100 °C, but no numerical results were reported therein. Because P is soluble in such metals as Pb and Bi [1947Mel], one may predict that detectable amounts of P should also dissolve in Hg. These facts suggest that the Hg-P diagram should be of a monotectic type, with a critical temperature higher than the boiling point of Hg (at normal pressure). Crystal structures of the elements and their lattice parameter data are listed in Table 1. By analogy with an ammonium amalgam [1997Gum], a “phosphonium amalgam” was formed [1889Bes] during the electroreduction of PH4 + on a Hg electrode at –25 to –40 °C, The PH 4 · radical possesses metallike properties that qualitatively approximate those of the alkali metals. The phosphonium amalgam, like the ammonium amalgam, should be stable in the solid state at temperatures lower than the Hg melting point.

Medical Pearl: Docetaxel-induced onycholysis

ends of the 3-way tap are capped to prevent air entry in the syringe. Because of the negative pressure, the skin bulges inside the syringe increasing the contact surface between the skin and the syringe. Therefore, vacuum leak from the contact area between the syringe and the skin usually does not occur. Application of a thin layer of white soft paraffin on the contact surface may further make the syringe leak-proof. On measuring negative pressure after 1 or 2 hours, no or negligible change in the negative pressure was noted. In conclusion, we provide a reference table for the required volume of air to be aspirated from 5-, 10-, and 20-mL syringes to achieve the desired negative pressure. Because the manometer constitutes the main bulk of the syringe suction blister apparatus, using the reference table eliminates its need and further simplifies the suction blister apparatus. REFERENCES 1. Kiistala U, Mustakallio KK. In vivo separation of epidermis by production of suction blisters. Lancet 1964;1:1444-5. 2. Falabella R. Epidermal grafting: an original technique and its application in achromic and granulating areas. Arch Dermatol 1971;104:592-600. 3. Gupta S, Kumar B. Epidermal grafting in vitiligo: influence of age, site of lesions, and type of disease on outcome. J Am Acad Dermatol 2003;49:99-104. 4. Koga M. Epidermal grafting using the tops of suction blisters in the treatment of vitiligo. Arch Dermatol 1988;124:1656-8. 5. Kiistala U. Suction blister device for separation of viable epidermis from dermis. J Invest Dermatol 1968;50:129-37. 6. Mukhtar, Singh S, Shukla VK, Pandey SS. Surgical pearl: suction syringe for epidermal grafting. J Am Acad Dermatol 1997;37: 638-9. 7. Lewis EJ. The mechanism of ‘‘suction.’’ J Am Acad Dermatol 1998;39:664. 8. Gupta S, Shroff S, Gupta S. Modified technique of suction blistering for epidermal grafting in vitiligo. Int J Dermatol 1999; 38:306-9. 9. Gupta S, Kumar B. Suction blister induction time: 15 minutes or 150 minutes? Dermatol Surg 2000;26:754-7. J AM ACAD DERMATOL FEBRUARY 2005 350 Pearls

361 OVIDUCT CILIARY CURRENTS IN BOVINE AND BUFFALO AT DAY 1 AFTER OVULATION

Buffalo present a low embryo recovery rate after superovulation, due to failure of oocyte entry into the oviduct. The aim of this study was to evaluate the effect of the estradiol-17� on oviduct ciliary currents in bovine and buffalo at Day 1 after ovulation. Six Nelore cows and six Murrah buffalo cows were synchronized with an intravaginal progesterone device (DIB�; Syntex, Argentina) plus 2 mg of estradiol benzoate intramuscular (i.m.) on Day 0 (D0). After eight days (D8) the device was removed and the animals received prostaglandin F2� analogue (0.15 mg i.m.; Prolise�; Tecnopec, Sao Paulo, Brazil) plus 400 IU of eCG (i.m.; Novormon�; Syntex). On D9, ovulation was induced with GnRH (25 �g i.m.; Gestran Plus�; Tecnopec). After 48 h the animals were slaughtered and the oviducts were removed and rinsed in a solution of Dulbeccos's phosphate-buffered saline with 1% gentamicin (DPBS + gentamicin). The oviduct was lavaged with Hank's balanced salt solution supplemented with 25 mM HEPES (HBSS), and the mesosalpinx and fimbria were removed. The oviduct was then carefully incised along its entire length. After the luminal surface was exposed, the oviduct was secured with the luminal surface exposed in a 150 � 20-mm dish containing a layer of paraffin. The oviduct was then completely submerged in 100 mL HBSS (Group 1 - G1, n = 5 bovine; G2, n = 7 buffalo) or 100 mL HBSS with 10 ng/mL estradiol-17� (G3, n = 6 bovine; G4, n = 4 buffalo; factorial 2 � 2) that had been prewarmed to 38.5�C. The dish containing the oviduct was incubated for 30 min at 38.5�C to allow equilibration of temperature and culture medium. After equilibration, the oviduct in the culture dish was placed on a stereomicroscope (SMZ-1T) and the luminal epithelium was observed (�30). To assess ciliary beat, 450 black microspheres (10 �m; Polybead�; Polysciences, Inc., Warrington, PA, USA) were applied to the luminal surface of the oviduct. The microspheres were applied dropwise (10 �L) to one portion of the infundibulum and the area of application was immediately observed to determine the direction of microsphere motion over approximately 1 min. The direction of motion was graduated in scale (0 = none, 1 = uterine, 2 = ovarian-uterine, and 3 = ovarian). Two-way analyses of variance was used to compare the effects of species (bovine � buffalo) and treatments (without estradiol � with estradiol) and the species-by-treatment interaction. The data were analyzed by General Linear Models procedure of SAS/STAT (SAS Institute, Inc., Cary, NC, USA) and the direction of motion was compared by the t test's LSD. There was no effect of species and treatment, and no species-by-treatment interaction. The direction of motion of microspheres was consistently toward the uterus (pro-uterine) for G1 (0.80 � 0.20), G2 (1.00 � 0.00), G3 (1.00 � 0.00), and G4 (1.00 � 0.33; P > 0.05). Analyzing the main effects, bovine presented score (0.94 � 0.05) similar to that of buffalo (1.00 � 0.17; P > 0.05). Animals treated without estradiol (0.92 � 0.08) showed the same score as animals treated with estradiol (1.00 � 0.12). In conclusion, the presence of estradiol-17� in culture medium had no effect on the oviduct ciliary currents in bovine and buffalo.This work was supported by FAPESP (02/03245-1; 03/00798-1), SPVS, Syntex, Cultilab, and Tecnopec.

A micropump operating with chemically produced oxygen gas

A novel oxygen micropump is described in this paper. Pumping power is generated through the chemical production of oxygen gas. Decomposition of hydrogen peroxide by aid of catalyst results in the production of oxygen. Hydrogen peroxide is separated by oily paraffin from catalyst before the start of decomposition reaction. The decomposition of hydrogen peroxide by catalyst is commenced through melting the paraffin by an underlaid microheater. An initial triggering of the micropump by input of electric current is sufficient for the continuous actuation through the decomposition reaction. Liquid sample in reservoir is pushed by the produced oxygen gas and flows through a microchannel. Commercially available thin paraffin layers can replace paraffin for easier fabrication. Moreover, the operation of oxygen micropump can be tightly controlled if hydrogen peroxide is decomposed only by heating. Oxygen micropump will be a preferable component of lab-on-a-chips (LOCs) as well as the source of pure oxygen for chemical systems.