Water Absorption Measurements Research Articles

The Influence of 30 Years Outdoor Weathering on the Durability of Hydrophobic Agents Applied on Obernkirchener Sandstones

The durability of eleven different water repellents applied on one sandstone type was studied after a long-term weathering at seven different locations in Germany. By measuring colour changes, it could be shown that the formation of black crusts, the deposition of particles and biogenic growth caused a gradual darkening as well as significant changes in total colour over time. Additionally, the water absorption behaviour was investigated with two different methods: applying a low pressure using the pipe method and capillary water absorption measurements from a wet underlay. Afterwards, the test results were analysed with four different evaluation methods: calculation of the protection degree from pipe method and capillary water absorption, determination of the velocity of water uptake during capillary water absorption and calculation of the damaged depth of the stone surface using single-sided NMR technique. The growing damaged depth leads to an increase of the water uptake velocity and to a decrease of the protection degree of the applied hydrophobing agents. Three protective agents based on isobutyltrimethoxysilane showed already after two years of outdoor weathering a clear loss of performance, which significantly increased after 30 years of exposure.

The reactive compatibilization of montmorillonite for immiscible anionic polyamide 6/polystyrene blends via in situ polymerization

ABSTRACTIn this paper, a novel method has been successfully developed to prepare the polyamide 6/polystyrene/montmorillonite (APA6/PS/MMT) blends. The X-ray diffraction analysis, differential scanning calorimetry, scanning electron microscopy analysis, contact angle measurement, water absorption measurement, thermogravimetric analysis and mechanical properties test were performed separately to study the effects of P(St-co-IEM)-MMT-MPS on crystallinity, morphology, water resistance, thermal stability and mechanical properties. The results indicate the addition of MMT can promote the formation of the γ-phase. Moreover, it can improve the interfacial compatibility, water resistance, thermal stability and toughness.

Study on effect of strength and durability parameters and performance of Self Compacting Concrete replacement with GGBS at different dosages

To investigate experimentally, the behavior of exterior beam-column joint and strength characteristics of Self Compacting Concrete (SCC) containing Viscosity Modifying Admixture (VMA), and Ground Granulated Blast Furnace Slag (GGBFS). Since there is no standard method of mix design is available for SCC. Hence mix design was arrived as per the rules of European Federation of National Associations Representing for Concrete (EFNARC). Marsh cone test was used to find the saturation of various kind of cements by adding the dosage of super plasticizer accordingly. In this investigation SCC was made by usual ingredients such as cement, fine aggregate, coarse aggregate, water and ground granulated blast furnace slag at various replacement levels (10%, 20%, 30%, 40%, and 50%), with that the Super Plasticizer (Glenium B233) and viscosity modifying agent (Glenium Stream 2) was used in appropriate amount for achieving the better flow in the concrete. The experiments were carried out by maintaining a constant water-powder ratio of 0.45. At various replacement levels the performance of freshly prepared SCC is checked by conducting tests such as slump flow, T50 slump flow, U-tube, L-box and V-funnel tests. Mechanical characteristics like Compressive, Split-tensile and Flexural strength examined. Also, the durability study for SCC after 28, 56 and 90 days curing was done by conducting a number of the tests like saturated water absorption, porosity, carbonation depth and alkalinity measurement

Fabrication of flat ceramic microfiltration membrane from natural kaolinite for seawater pretreatment for desalination and wastewater clarification

The aim of this work is the manufacturing of flat microfiltration membrane made from Moroccan natural kaolinite clay and corn starch as porosity agent. The membrane was prepared by uniaxial pressing technique and sintering at 1,100 degrees C. The effect of starch on membrane features was investigated from 0 to 15 wt.%. The membrane has a diameter of 37.8 mm and a thickness of 2.3 mm. In order to optimize its properties, prepared membrane was characterized in terms of apparent porosity, water absorption, apparent density, mechanical strength, pore size, microstructure, and water permeability measurements. Experimental results showed that the membrane prepared with 10 wt.% of starch is considered as an optimized membrane which has an average pore size of 2.3 mu m, the mechanical strength of 20.2 MPa, and permeability of 2,129 L h(-1)m(-2) bar(-1). The optimized membrane was applied for pretreatment of raw seawater for desalination and clarification of agro-food effluent using dead-end filtration under pressure of 0.12 bar. Filtration results showed that turbidity rejection achieves 73% and 99%, respectively for raw seawater and agro-food model effluent.

An experimental study of selected Jurassic carbonate samples from north-eastern Tunisia

The industrial development of the outcrops in the Tunis-Zaghouane area could represent an important economic driver for the country. The main structures are introduced and illustrated with onsite field observations. Moreover, samples which were extracted from the selected regions and are characterized based on measurements of porosity, water absorption and abrasion loss coefficients. The experimental results showed a negligible variation of densities, demonstrated a linear correlation between connected porosity and overall water absorption. In addition, experimental result confirms that outcrops from Jebel Zaghouane, Jebel Hammam Zriba and Jebel Hammam Jedidi could be developed as construction materials.

Synthesis and Characterization of Collagen-Chitosan-Sodium Hyaluronates as Artificial Cornea

As reported by Riset Kesehatan Dasar, Indonesia facing a serious problem of blindness with 966.326 cases of 2 million population in 2013. Gold standard such as keratoplasty couldn’t completely heal corneal injury due to the recipient’s rejection and limited donor. In order to overcome those concerns, artificial corneal tissue needs to be developed to produce an artificial cornea which is biocompatible, supports corneal function, and applicable. This research was conducted to provide an initial description of Collagen – Chitosan - Natrium Hyaluronate (Col-Chi-NaHA) as an artificial cornea through FTIR analysis, hydrophilicity and water absorption measurement. The artificial cornea was synthesized by forming ratio of collagen 20% w/v and chitosan 10% w/v, both solutions were dissolved in 0,1 M and 0,6 M acetic acid separately. Into the mixed solution, NaHA was dripped slowly with variation of 0%, 0,3%, and 0,6%. The homogenous solution was cast and heated for 24 hours at 35°C. The dry membranes were neutralized to obtain a pH around 7. From the analysis known that all of the characteristic bands of Col-Chi-NaHA could be observed in obtained membranes. Water absorption measurement demonstrated percentages over 90% on all membranes. The contact angle of obtained membranes was decreased by the addition of NaHA. The results showed that artificial cornea made from Col-Chi-NaHA successfully fabricated has hydrophilic properties to support cellular interaction and provide hydration to keep eye’s clarity and permeability. Therefore, Col-Chi-NaHA could may be a suitable material for the tissue-engineered cornea.

Effects of granite waste addition on the technological properties of industrial silicate based-ceramics

Granite waste has been studied as an eco-friendly raw material in red clay processed-ceramics. However, its influence on the technological properties of industrial porcelain tile formulations has been little discussed, which leaves gaps in this field. This work aims to understand the effects of granite waste content on the physico-mechanical properties of silicate based-ceramics (red clay and porcelain tile). Starting materials were characterized by x-ray fluorescence (XRF), x-ray diffractometry (XRD), particle size distribution, and thermal analyses (DTA and TG). The effects of granite waste addition on the technological properties of sintered samples were evaluated by measuring water absorption, apparent density, and flexural strength. XRD pattern revealed that the granite waste consists of quartz, muscovite, potassium feldspar, anorthite, cordierite, calcite, and dolomite, which is similar to that of raw materials used in the ceramic industry. The characterization of the raw materials showed that granite waste is a promising material to be used in the ceramic industry, without impairing mechanical strength of porcelain tile for additions of up to 12 wt%. This study reports a high mechanical strength of 40 MPa for samples with 3 wt% waste content sintered at 1150 °C. Granite waste additions showed values of water absorption (<18.3%, for samples with up to 50 wt% granite waste content) and flexural strength (>7.3 MPa, for samples with up to 38 wtwt% granite waste) in good agreement with the range established by the Brazilian standard for perforated bricks and roof tiles.

Mechanical and durability properties of bagasse ash-blended high-performance concrete

The use of supplementary cementitious materials has become an integral part of high-strength and high-performance concrete mix design, which may be natural by-products or industrial wastes. Some of the frequently used supplementary cementitious materials are fly ash, silica fume, ground granulated blast furnace slag, rice hush ash and bagasse ash (BA). BA (sugarcane industry waste product) is considered to be an active pozzolan because of its large surface area with significant amount of amorphous SiO2. The mix design for high-performance concrete is done as per the method proposed by P. C. Aitcin. This method is simple and follows the same approach as ACI 211-1 standard practice for selecting proportion of normal, heavy and mass concreting. Ordinary Portland cement was replaced at different levels of 0%, 5%, 10%, 15% and 20% by BA. This investigation presents results on the strength and durability properties of high-performance concrete with and without BA, which includes cube compressive strength, splitting tensile strength, flexural strength, saturated water absorption, sorptivity, porosity, impact test and alkalinity measurement. The test results indicate that the incorporation of BA up to 10% provides improved properties of hardened concrete.

The effectiveness of ethyl silicate as consolidating and protective coating to extend the durability of earthen plasters

In the heritage protection, one of the most interesting scenarios is the preservation of the original materials. In this case, the surfaces are generally treated to consolidate them. The aim of this paper is to evaluate the effect of ethyl silicate coatings on surface consolidation, water absorption and porosity of earthen materials. Peeling tests, water absorption measurements (capillary and Karsten) and textural alteration analyses were conducted by optical microscopy. In addition, the protective role of the ethyl silicate coatings against rainwater, HCl rain and H2SO4 rain was evaluated to compare the durability of coated and control samples. It was found that ethyl silicate substantially improved the above properties as well as microstructural features of the samples. Scanning Electron Microscopy and EDX mapping revealed the coating was not regularly spread on the surface. Despite this, Mercury Intrusion Porosimetry tests showed the total porosity of samples coated with ethyl silicate was clearly reduced.

Predicting the solar evaporative cooling performance of pervious materials based on hygrothermal properties

Pervious pavement has been regarded as an effective technique for both water storm management and overheating prevention. However, compared with its widely recognized permeability capability, its solar evaporative cooling performance remains under debate after post-occupancy evaluation; thus, it is essential to predict the solar evaporative cooling ability before practical use. Hygrothermal properties (i.e., albedo, water absorption, and water retention properties) are key factors that affect the solar evaporative cooling effect of pervious materials and could be extracted as predictive indicators. However, an approach for assessing the water absorption and retention properties has not been well studied. Therefore, this study aimed at characterizing a feasible method for testing water absorption and retention properties of pervious materials as well as the influence of albedo on the solar evaporative cooling performance. Five widely used pervious materials were selected as research subjects, and three hydrological test methods, including the integral immersion test, partial immersion test, and rainfall simulation test, were conducted for comparing the feasibility of measuring water absorption and retention properties. Furthermore, the solar evaporative cooling performance of pervious materials with high and low albedo was also investigated. The results reveal that the partial immersion test has the highest accuracy for evaluating the water absorption and retention properties of pervious materials. Although the high albedo could weaken the evaporation rate, pervious materials with high albedo could also achieve better solar evaporative cooling performance. The results of this study support the proper selection of pervious materials to alleviate urban overheating.

Preparation and Characterization of Waterborne Polyurethane Modified by 4-Maleimidophenol to Enhance the Mechanical and Thermal Properties

A series of 4-maleimidophenol (4-HPM) modified waterborne polyurethane (MWPU) emulsions were successfully synthesized, using isophoronediisocyanate (IPDI), polycaprolactonediol (PCL, Mw = 1000), 1,4-butanediol (BDO), 2,2-dimethylolpropionic acid (DMPA), trimethylolpropane (TMP) and triethylamine (TEA) as raw material. The effects of 4-HPM content on the structure, morphology and physical properties of the MWPU were characterized by Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscope, X-ray diffraction, thermogravimetric analysis, water absorption measurement, water contact angle measurement and tensile testing. The results revealed that with 4-HPM introduced into the WPUs backbones, the crystallinity, the hardness, tensile strength, water resistance and thermal stability of MWPU films were significantly augmented. Moreover, when the content of 4-HPM was 4.0 wt %, the tensile strength of the MWPU film was up to 46.4 MPa, improved about 134.19% (measurement error ±0.001) compared with WPU (19.8 MPa). When the content of 4-HPM was 6.0 wt %, the end decomposition temperature of the film was up to 489.6°C, improved 12.6% compared with WPU (434.8°C).

Preparation and properties of cross-linked waterborne polyurethane based on solvent-free route

Intrinsic cross-linked waterborne polyurethane (CWPU) was successfully synthesized for the first time through solvent-free condensation polymerization, in which green castor oil (CO) was used as the cross-linking agent. The totally solvent-free process was realized by using hydrophilic polypropylene glycol as hydrophilic segment, which was synthesized by the esterification of polypropylene glycol with pyromellitic dianhydride. The effect of CO content in the soft segment of the prepared CWPU on emulsion properties was investigated by laser particle size distribution test, and the prepared CWPU emulsion showed uniform size distribution (0.117–0.275 µm) and milky white appearance after storing at ambient temperature for 6 month. Additionally, the effect of CO content in CWPU films on static mechanical properties, dynamic mechanical properties, hydrophilicity and thermal stability was also studied by tensile test, dynamic mechanical analysis, water absorption and contact angle measurement as well as thermogravimetric analysis. The prepared cross-linked CWPU films have good stability and outstanding mechanical strength (11.94–34.51 MPa), making them adequate supplement for the conventional waterborne polyurethanes.

CHARACTERISTICS OF PHYSICAL PROPERTIES OF WOOD POWDER COMPOSITES AND BAGASSEAS CONSTRUCTION MATERIALS OF SHIP

Parameters for measuring the physical properties on this research are divided into three elements, including measurement of weight, water absorption, and density. This research was conducted from January to March 2018 to determine the physical properties of wood powder composites and bagasse. The manufacturing and testing process refers to the ASTM and JIS standards. Weight and density testing refer to the ASTM D 792 standard while the water absorption test refers to the JIS A5908 standard. The results showed that the density of wood powder was 0.4175 gr / cm3, and the bagasse was 0.3125 gr / cm3. Then, fiber absorption in units of volume to water and resin were 16.88% and 13.75% respectively. The results showed that the largest water absorption was found in composite wood powder 60% and bagasse 40%, which was 13.47%, and for the highest density values found in wood powder composites as much as 80% or 1,078.29 kg / m3

Investigation of Fiber Surface Treatment Effect on Thermal, Mechanical and Acoustical Properties of Date Palm Fiber-Reinforced Cementitious Composites

High energy consumption in the building sector appeals for the implementation and the improvement of innovative approaches with low-environmental impact. The development of eco-friendly composites as insulating materials in buildings provides practical solutions for reducing energy consumption. Different mass proportions (2.5%, 10%, and 20%) of untreated and chemically treated palm fibers were mixed with (cement, water and sand) so as to prepare novel composites. Composites were characterized by measuring water absorption, thermal conductivity, compressive strength and acoustic transmission. The results reveal that the incorporation of untreated and chemically treated date palm fibers reduces novel composites’ thermal conductivity and the mechanical resistance. Thermal measurements have proved that the loading of fibers in composites decreases the thermal conductivity from 1.38 W m−1 K−1 for the reference material to 0.31 W m−1 K−1 for composites with 5% of treated and untreated fibers. The acoustical insulation capacity of untreated palm fiber-reinforced composites (DPF) was the highest at 20% fiber content, whereas treated palm fiber-reinforced composites (TPF) had the highest sound insulation coefficient for fiber content lower than 10%. Compressive strength, thermal conductivity and density correlation showed that only chemically treated fiber-reinforced composites (TPF) are good candidates for thermal and acoustic building insulations.

Compostable composites of wheat stalk micro‐ and nanocrystalline cellulose and poly(butylene adipate‐co‐terephthalate): Surface properties and degradation behavior

ABSTRACTAn agricultural waste, the wheat stalk, was used for the extraction of microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC) via a series of thermochemical and mechanical treatments. The MCC and NCC were then compounded with the biodegradable polymer, poly(butylene adipate‐co‐terephthalate), PBAT, by melt mixing. The properties of the composites were evaluated by soil composting, contact angle and water absorption measurements, scanning electron microscopy (SEM) and gel permeation chromatography (GPC). The cellulosic filler was found, as per SEM results, to uniformly disperse in the polymer matrix forming a quite homogeneous composite which visibly degraded completely within a few months under soil composting and showed high water absorption, these properties being enhanced with the filler content. Compared to the neat PBAT, the composites showed enhanced surface hydrophilicity thereby increasing the ability of degradation. In spite of seemingly remarkable change in mechanical stability of the polymers under soil burial for several months, relatively low lowering of the molecular weight was observed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48149.

Poly(ether ketone) composite membranes by electrospinning for fuel cell applications

This work is dedicated to preparation of the composite membranes to control the water absorption and dimensional stability of a highly sulfonated poly(ether ketone) matrix. To achieve this goal, the non-sulfonated poly(ether ketone) fibers are prepared by electrospinning process and then fibers are impregnated by highly sulfonated poly(ether ketone). Both highly sulfonated and non-sulfonated polymers are synthesized by condensation polymerization reaction and are characterized by spectroscopic methods. The water absorption measurements indicate that introducing 20 and 30 wt% of non-sulfonated fibers lead to the water absorption of 31 and 25% respectively, in comparison to water absorption of highly sulfonated matrix that is 54%. The presence of fibers also improves the mechanical strength of membranes. Tensile strength reaches from 27 to 81 MPa by addition of 30 wt% electrospun fibers. Moreover, in H2/O2 fuel cell performance test, the composite membranes show current density in the range of 700–1090 mA cm−1 at different cell temperatures and backpressure amounts. Also proton conductivity of the samples is examined by electrochemical impedance spectroscopy and the values are between 0.05 and 0.16 S cm−1. Morphology of the fibers and membranes is studied by scanning electron microscopy as well.

Zirconium phosphate changing hygroscopicity of polyamide-6 in nanocomposites PA-6/ZrP

Hygroscopicity can be understood as ability of any material to absorb water. This investigation aims to study the effect of lamellar zirconium phosphate (ZrP) in the hygroscopicity of poliamide-6 (PA-6). In situ (PA-6/ZrP) nanocomposites were prepared during the polymerization of caprolactam. Structural, thermal, crystallographic and rheological characteristics were assessed by infrared spectroscopy (FTIR), thermogravimetry, differential scanning calorimetry, wide-angle X-ray diffraction (WAXD), rheological and water absorption measurements. FTIR evidenced strong interaction between polymer/nanofiller. According to the kind of nanofiller, changes in PA-6 thermal stability and crystallinity degree were noticed. Formation of PA-6 α-crystal, microcomposite and possibly exfoliated nanocomposite was predicted by WAXD. Rheological measurements evidenced great interaction between PA-6 and nanofillers. PA-6 hygroscopicity was strongly influenced by ZrP-attained value almost 40% lesser as compared to neat PA-6.

Production of geopolymer mortar system containing high calcium biomass wood ash as a partial substitution to fly ash: An early age evaluation

This paper presents an investigation on the feasibility of inclusion of biomass wood ash (BWA) as a partial replacement material for fly ash (FA) in preparation of blended BWA-FA geopolymer mortars. The blended mortar systems for this study were prepared at three replacement ratios of FA by BWA of 10%, 20% and 30% by binder mass. The engineering properties of the BWA-FA geopolymer mortars were evaluated using compressive strength, flexural strength, water absorption and total porosity measurements. Microstructural and phase composition analysis were also conducted to assess the obtained results and compared with a control mortar mix containing 100% FA at different ages of 3, 7 and 28 days. The results showed the inclusion of BWA up to 20% resulted in higher strength and porosity characteristics than the control mix at age of 3 and 7 days. However, at age of 28 days, the geopolymer contains 10% BWA of the total binder was the only blended mixture that exhibited higher compressive strength and lower total porosity than the control mix. The phase composition results of the blended mixtures at 28 days confirmed the formation of calcium polysialate and calcium silicate hydrate gels coexisted with sodium polysialate phase.

Effective elongation properties of cellulose–natural rubber composite hydrogels having interconnected domain

This report describes progress in the development of cellulose hydrogel by blending with natural rubber (NR). Cellulose regenerated from the bagasse sugarcane was used for this study. Although cellulose and NR have a considerably low mutual affinity, composite hydrogels with various cellulose and NR contents were prepared using a wet-phase inversion method. The maximum amount of NR that can be loaded into the cellulose hydrogel was about 30% vol. Once NR is introduced into the cellulose hydrogels, the obtained hydrogel became translucent and eventually opaque with increasing NR loading. Measurements of water absorption, the water contact angle, and evaluation of fourier-transform infrared spectroscopoy (FTIR) spectra revealed that the presence of NR decreases the water affinity of the hydrogels. Nevertheless, it is noteworthy that the composite hydrogels had higher tensile strength and better elastic properties than the pristine hydrogel. The results showed that the obtained composite hydrogels can be elongated several times to their original length. The enhancement of both properties was proportional to the amount of NR included. Results of scanning electron microscope (SEM) images showed NR present inside the hollow of the cellulose hydrogel, forming interconnected domains. One can infer that the increase of mechanical and elastic properties is attributable to the presence of these interconnected structures.

Water absorption measurements on WPCs: Assessment of size and direction dependencies in order to design fast and accurate quality control tests

Abstract Wood-plastic composites (WPCs) are water-sensitive materials. Standards describe water absorption protocols on composites to obtain results after a long period of aging. From an industrial point of view, it is necessary to obtain the same information (i.e. equilibrium water content and absorption kinetics) over a short time. In this paper, we propose a new immersion aging protocol based on cubes taken from a reference WPC. This new methodology was validated by varying several test parameters (temperature, sample size, etc.) and applying it to other WPCs. Cubic samples were found to diverge from a Fickian behavior after a certain time of aging because of swelling and cracking that creates another characteristic pore scale and an increase of diffusion coefficient. Compared to the same formulation of cubic samples, the plate samples usually used for water absorption didn't crack. Fick's law approximation was used to determine the diffusion coefficient on plate materials. The coefficients measured in the three directions of WPC decks and a 3D model enabled us to recalculate the apparent coefficient of cubic samples for short-term absorption. Comparison of diffusion coefficients for short and long-term absorption showed the water concentration dependence of composites. Long-term diffusion coefficients and swelling stress coefficients were used in the pseudo-Fickian model to predict the water absorption behavior for composites undergoing water concentration dependence.