Difference in the micro-dynamics mechanism between aromatic nylon and aliphatic nylon during water absorption: spectroscopic evidence

2018 ◽  
Vol 20 (41) ◽  
pp. 26764-26776 ◽  
Author(s):  
Liyang Jia ◽  
Gehong Su ◽  
Qiang Yuan ◽  
Xueqian Zhang ◽  
Tao Zhou
Keyword(s):  
Water Absorption ◽  
Polyamide 6 ◽  
High Humidity ◽  
Spectroscopic Evidence ◽  
Barrier Performance ◽  
The Difference

The difference in the micro-dynamics mechanism between aromatic nylon and aliphatic nylon during water absorption was studied to explore the reason for the significantly smaller decline of barrier performance of poly(m-xylene adipamide) (MXD6) film than that of polyamide 6 (PA6) film under high humidity.

scholarly journals Pengaruh minuman teh pada pemakai basis gigi tiruan nilon termoplastik terhadap penyerapan air dan stabilitas warnaThe effect of tea on the thermoplastic nylon denture base wearers on water absorption and colour stability

2020 ◽  
Vol 32 (1) ◽  
pp. 66
Author(s):  
Siti Wahyuni ◽  
Chairunnisa Ricca
Keyword(s):  
Water Absorption ◽  
Base Material ◽  
Acrylic Resin ◽  
Polyamide 6 ◽  
T Test ◽  
Laboratory Research ◽  
Colour Stability ◽  
Denture Base ◽  
Group A ◽  
Group B

Pendahuluan: Nilon termoplastik merupakan basis gigi tiruan yang banyak diminati oleh para dokter gigi karena memiliki beberapa keuntungan dibandingkan bahan basis gigi tiruan resin akrilik. Diantara jenis nilon termoplastik yang sering dijadikan basis gigi tiruan adalah poliamida 6 dan poliamida mikrokristalin. Poliamida Mikrokristalin merupakan poliamida generasi baru yang dibuat untuk menanggulangi kelemahan pada poliamida sebelumnya. Tujuan penelitian ini adalah menganalisis pengaruh minuman teh pada pengguna gigi tiruan nilon termoplastik terhadap penyerapan air dan stabilitas warna. Metode: Jenis penelitian ini adalah experimental laboratoris. Jumlah sampel terdiri dari 40 dengan  ukuran diameter 15 mm ± 1 mm dan ketebalan 0.5 mm ± 0,1 mm (ISO 4049) dan terbagi menjadi 4 kelompok (kelompok A poliamida 6 dan kelompok B poliamida mikrokristalin untuk penyerapan air serta kelompok C poliamida 6 dan kelompok D poliamida mikrokristalin untuk uji stabilitas warna). Semua sampel direndam dalam larutan teh selama 7 hari. Data dianalisis dengan uji T Independen. Gambaran mikroskopis sampel diuji dengan SEM Hasil: Berdasarkan uji T Independen hasil menunjukkan perbedaan yang signifikan diantara kelompok A dan B, C dan D.  Uji T independen menunjukkan perbedaan yang signifikan diantara kelompok A dan B, C dan D (p=0,0001, p<0,05) Simpulan: Terdapat pengaruh minuman teh pada pengguna gigi tiruan nilon termoplastik. Poliamida Mikrokristalin memiliki penyerapan air yang lebih sedikit dan stabilitas warna yang lebih baik dibandingkan Poliamida 6.Kata kunci: Nilon termoplastik, poliamida 6, poliamida mikrokristalin, penyerapan air, stabilitas warna, SEM. ABSTRACTIntroduction: Thermoplastic nylon is a denture base mostly demanded by dentists due to its several advantages over acrylic resin denture base material. Among the types of thermoplastic nylon that are often used as denture bases are polyamide 6 and microcrystalline polyamide. Microcrystalline polyamide is the new generation of polyamides created to overcome the weaknesses of previous polyamides. The purpose of this study was to analyse the effect of tea on thermoplastic nylon denture wearers on water absorption and colour stability. Methods: This research was experimental laboratory research on 40 samples with a diameter of 15 mm ± 1 mm, and a thickness of 0.5 mm ± 0.1 mm (ISO 4049), divided into four groups (Group A was the polyamide 6; Group B was the microcrystalline polyamide on the water absorption; Group C was polyamide 6; and Group D was microcrystalline polyamide on the colour stability). All samples were immersed in the tea solutions for 7 days. Data were analysed with independent t-test. The microscopic structure was analysed using the scanning electron microscope (SEM). Results: The results showed significant differences between group A, B, C, and D. The independent t-test also showed significant differences between group A, B, C, and D (p = 0.000; p < 0.05). Conclusion: There is an effect of tea on the thermoplastic nylon denture wearers. Microcrystalline polyamides have less water absorption and better colour stability than Polyamide 6.Keywords:  Polyamide 6, thermoplastic nylon, microcrystalline polyamide, water absorption, colour stability, SEM.

Preparation and Characterization of CCCW/Foamed Concrete Composite

2011 ◽  
Vol 261-263 ◽  
pp. 13-18
Author(s):  
Ke Qing Li ◽  
De Ping Chen ◽  
Shi Li Zhang ◽  
Bao Shun Liu
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Heat Insulation ◽  
High Humidity ◽  
Underground Engineering ◽  
New Approach ◽  
Foamed Concrete ◽  
Insulation Performance

Aimed at improving the waterproofing property of foamed concrete, a heat-insulating and waterproofing composite applied in underground engineering was prepared by using cementitious capillary crystalline waterproofing material and foamed concrete. The properties of foamed concrete and composite such as compressive strength, water absorption and thermal conductivity were tested and contrasted, and the compounding reaction mechanism was analyzed. The results show that, compared with foamed concrete, the water absorption of composite has been significantly reduced while the heat-insulating property of foamed concrete is maintained and the overall waterproofing and heat-insulation performance has been significantly improved. A new approach solving underground heat-harm such as high temperature and high humidity is provided.

Annual differences in quality of leaf litter of aspen (Populus tremuloides) affecting rates of decomposition

1988 ◽  
Vol 66 (10) ◽  
pp. 1940-1947 ◽  
Author(s):  
Barry R. Taylor ◽  
Dennis Parkinson
Keyword(s):  
Water Absorption ◽  
Leaf Litter ◽  
Populus Tremuloides ◽  
Decomposition Rate ◽  
Rocky Mountains ◽  
Absorption Rate ◽  
Trembling Aspen ◽  
Leaching Loss ◽  
The Difference

Freshly fallen leaf litter was collected from a stand of trembling aspen (Populus tremuloides Michx.) in the Rocky Mountains of Alberta each autumn from 1981 through 1984. Leaves from 1981 and 1982 were yellow, waxy, and strong. Leaves from 1983 were pale brown and very brittle, and almost 1% of them suffered symmetrical deformities. Leaves from 1984 were composed of 80% yellow leaves and 20% green leaves, which apparently abscissed before senescence. Green and yellow 1984 leaves were distinctly different with respect to total (3 days) leaching loss, leachate conductivity, and proportions of ash, cellulose, and labile material. Green 1984 leaves contained twice as much nitrogen as yellow ones (13.1 vs. 6.5 mg∙g−1) and significantly more phosphorus (1.6 vs. 1.3 mg∙g−1). Leaves of different years varied widely with respect to leaf mass, water absorption rate, mass and conductivity of leachate, and proportions of cellulose, labiles, lignin, and ash, but there was no consistent ordering among years; leaves of different colouration (especially 1981 and 1983) were often physicochemically similar, while leaves identical in appearance were often chemically different. Small but significant differences in N and P concentrations among years were removed by 2 h leaching. Leaves of 1981 decomposing in laboratory microcosms at 26 °C lost less mass than either 1982 or 1983 leaves after 1 month, but not after 2 months. Ability of the cuticle to resist water absorption was probably responsible for the difference in initial decomposition rate.

Collection and analysis of absorbate from proximal straight tubules

1981 ◽  
Vol 241 (6) ◽  
pp. F597-F604 ◽  
Author(s):  
D. W. Barfuss ◽  
J. A. Schafer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Water Absorption ◽  
Glucose Concentration ◽  
Volume Absorption ◽  
Steady Rate ◽  
Straight Tubules ◽  
The Difference ◽  
Solute Composition

When isolated segments of rabbit proximal straight tubules were perfused under oil at 37 degrees C, we observed that droplets of absorbate formed on the peritubular surface. Volume absorption under these conditions was the same as with customary aqueous bathing solutions when calculated either from the rate of absorbate formation (0.39 +/- 0.03 nl X min-1 X mm-1) or from the difference in measured perfusion and collection rates (0.37 +/- 0.04 nl X min-1 X mm-1). Absorbate formation continued at a steady rate for at least 2 h but was inhibited by 71% at 28 degrees C. The absorbate was found to have a composition that differed from the perfusate, as would be expected in the presence of preferential absorption of glucose, amino acids, and HCO-3. The Cl- concentration in the absorbate was 11.2 +/- 1.8 mM less than in the perfusate. The glucose concentration in the absorbate was 4.5 mM compared with 0.9 mM in the perfusate. Finally, the nonmetabolizable amino acid cycloleucine, which was added to the perfusate at 0.35 mM, had a concentration of 2.9 mM in the epithelial cells compared with 1.6 mM in the absorbate. These data establish the usefulness of this technique for examining solute and water absorption in the proximal nephron and show that the absorbate can differ considerably in solute composition from the luminal perfusate.

Influence of Water Absorption on Static Friction of Pure and Friction-Modified PA6 Polymers

2019 ◽  
Vol 799 ◽  
pp. 59-64
Author(s):  
Igor Velkavrh ◽  
Stefan Klien ◽  
Joel Voyer ◽  
Florian Ausserer ◽  
Alexander Diem
Keyword(s):  
Water Absorption ◽  
Static Friction ◽  
Polyamide 6 ◽  
Coated Steel ◽  
Friction Modifiers ◽  
Test Conditions ◽  
Influence Of Water ◽  
Steel Surfaces ◽  
Contact Pressures ◽  
Lubrication Conditions

In the present study, static coefficients of friction of pure and friction modified (FM) polyamide 6 (PA6) polymers against primer-coated steel surfaces were investigated under a series of nominal contact pressures and by considering the influences of water absorption by the polymer, temperature, counter-body surface roughness and lubrication conditions. Under the majority of the test conditions investigated, FM PA6 exhibited lower static friction than pure PA6. Under unlubricated conditions, this was due to the low adhesion of the FM PA6 provided by its friction modifying inclusions; while under lubricated conditions, a combination of softening due to water absorption and decreased adhesion provided by its friction modifiers enabled lower static friction, especially at medium and high contact pressures.

scholarly journals Water Absorption and HEMA Release of Resin-Modified Glass-Ionomers

2009 ◽  
Vol 03 (04) ◽  
pp. 267-272 ◽  
Author(s):  
Nilufer Celebi Beriat ◽  
Dilek Nalbant
Keyword(s):  
Water Absorption ◽  
High Performance ◽  
Deionized Water ◽  
Glass Ionomer Cements ◽  
Glass Ionomer ◽  
Time Intervals ◽  
Significance Level ◽  
Glass Containers ◽  
Resin Modified Glass Ionomer ◽  
The Difference

ABSTRACTObjectives: The aim of this study was to evaluate the water absorption and the amount of hydroxyethyl metacrylate (HEMA) level released from various resin modified glass ionomer cements.Methods: Advance, Vitremer and Protec-Cem resin modified glass ionomer cements were used to evaluate the HEMA release. Ten specimens were fabricated from each cement in 10 × 1 mm height. Thirty specimens were immersed in glass containers filled with 20 ml deionized water. 1 ml solution was taken from the container at 10 minutes, 1 hour, 24 hour and 7 days intervals from each group and analyzed with high performance liquid chromatography (HPLC) machine and the results are presented in ppm. The data were subjected to Kruskal-Wallis, Mann-Whitney and Wilcoxon tests at a 0.05 significance level.Results: At all time intervals Vitremer showed highest HEMA release (10 min: 54.2 ppm; 1 h: 86.8 ppm; 24 h: 93.4 ppm) (P=0.0001). At the end of 10 minutes and first hour, following Vitremer, HEMA release was highest for Protec-Cem (10 min: 14.8 ppm; 1 h: 23.6 ppm) and then Advance (10 min: 5.5 ppm; 1 h: 18.8 ppm) (P<.05). Water absorption tests were performed according to the specifications of ISO 4049. Water absorption was highest for Vitremer and lowest for the Protec-Cem and the difference among cement groups was significant (P<.005).Conclusions: Vitremer showed the highest HEMA release and water absorption values and Protec-Cem showed the lowest values. HEMA release by time was significant for Advance cement. This release may be relevant both to the risk of adverse pulpal responses in patients and to the risk of allergy in patients and dental personnel. (Eur J Dent 2009;3:267-272)

Polarization-Division Interferometry: Approach for Biomedical Infrared Imaging

1994 ◽  
Vol 48 (11) ◽  
pp. 1403-1409 ◽  
Author(s):  
Prasad L. Polavarapu ◽  
Gang-Chi Chen ◽  
Zhengyu Deng
Keyword(s):  
Fourier Transform ◽  
Water Absorption ◽  
Infrared Absorption ◽  
Infrared Imaging ◽  
Fourier Transform Infrared ◽  
Infrared Light ◽  
Measured Signal ◽  
Differential Interaction ◽  
Unique Approach ◽  
The Difference

Conventional Fourier transform infrared absorption spectroscopy is not suitable for most biological and biomedical studies because of strong infrared absorption by water. For wavelengths where samples absorb more than one unit of absorbance, most measurements with conventional Fourier transform infrared spectroscopy suffer from photometric inaccuracies. However, water is not sensitive to the polarization of the infrared light, but living systems can exhibit differential interaction to the polarized nature of light. In a method where the measured signal directly represents the difference in polarized absorptions, the water component becomes spectrally transparent (although the number of photons reaching the detector is still attenuated by water) and facilitates the measurements appropriate for biological systems. Verification of this principle is reported here for the use of a new midinfrared polarizationdivision interferometer developed in our laboratory. With the amide I vibrational band of a nylonll film which overlaps with the water absorption band at 1647 cm-', the associated dichroism is measured in the presence of varying amounts of interfering water absorption. It is found that dichroism can be measured even in the presence of strong interfering absorption from water. This observation suggests that the present method provides a unique approach, as well as the necessary impetus, for initiating biomedical infrared imaging studies.

Effect of nanofiber diameter on water absorption properties and pore size of polyamide-6 electrospun nanoweb

2014 ◽  
Vol 84 (19) ◽  
pp. 2045-2055 ◽  
Author(s):  
Amir Houshang Hekmati ◽  
Nabyl Khenoussi ◽  
Habiba Nouali ◽  
Joël Patarin ◽  
Jean-Yves Drean
Keyword(s):  
Water Absorption ◽  
Pore Size ◽  
Mercury Porosimetry ◽  
Average Diameter ◽  
Polyamide 6 ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Absorption Properties ◽  
Absorption Time ◽  
Nanofiber Diameter

Electrospinning is a common method used to produce nanofiber from almost all types of polymers. By changing effective parameters of this process, especially polymer solution concentration, it is possible to produce nanoweb that consists of nanofibers with different averages of diameter. Here, the effect of nanofibers’ diameter on textural properties (water absorption time and pore size) of polyamide-6 nanoweb has been studied. In this way, three nanowebs with nanofibers’ average diameter of 111, 151, and 318 nm were electrospun from three different concentrations of 15, 20, and 25 wt%, respectively. Contact angle measurement and mercury porosimetry were used to investigate the nanowebs’ water absorption properties and porosity (pore size). The results from the water absorption test demonstrated that the absorption time of a 2 µL water droplet was remarkably shorter for electrospun nanoweb with larger nanofiber diameter. Nanowebs electrospun from 15 and 20 wt% concentrations had roughly the same absorption regime, while for 25 wt% the absorption regime was totally different. Mercury porosimetry of electrospun nanowebs revealed that the pore size in the nanoweb structure decreased by decreasing average diameter of nanofibers. The results of this study showed that contact angle measurement and mercury porosimetry tests could be used as complementary methods to scanning electron microscopy and atomic force microscopy and presented as promising methods to study the textural and physical properties of electrospun nanowebs.

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