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Strength properties of paper are of great significance in terms of its mechanical performance and are attributed to cellulosic fibers. When filler is used in papermaking, the cost and strength properties get reduced but optical properties are improved. So far, modification of fillers using chitosan (CH) is not explored in such a way that all aspects of wet-end of papermaking get covered. The novelty lies in showing the effect of CH as filler modifier at various doses on different fillers and the wet-end application of modified fillers at different doses along with other additives used in papermaking. The impact of addition of modified fillers on end paper properties is also analyzed. Here, CH was applied to modify fillers characteristics so that the ash in paper can be increased without compromising the strength properties. Three different doses (0.25%, 0.50% and 1.00%) of CH were added to the fillers. The addition of modified fillers to bleached mixed hardwood (BMHW) pulp increased the filler retention in paper while the reduction in strength properties was found to be less and in some properties even an increase was observed. The particle size distributions of fillers were found to be affected after modification of fillers. [ABSTRACT FROM AUTHOR]

There is current interest in using agro-based biopolymers in industrial applications. Because cottonseed protein is abundantly available, it would be useful to explore its feasibility as a polymeric additive and possible substitute for petroleum-based materials. In this work, we studied cottonseed protein isolate as a paper additive and observed its effects on the paper’s dry and wet strength. The tensile strength of paper was found to vary with the amount of the protein applied. By application of an 11% protein solution to the paper, the dry and wet strength increased by 33 and 16% compared with the paper by itself, respectively. The combined use of cottonseed protein and an acid (acetic, adipic, aspartic, and citric acids) to promote adhesion resulted in even greater dry paper strength but not in greater wet paper strength. Thermogravimetric analysis, infrared spectroscopy, and scanning electron microscopic studies suggested that the protein interacted with acid and that both components interacted with paper fibers to produce increased strength. [ABSTRACT FROM AUTHOR]

The major benefits of using polymers based EOR include an increase of viscosity of the injected water, increasing sweep efficiency, and reduction in mobility ratio. A variety of polymers are available in the market, yet every polymer is unusable for any field, thus posing selection and how to use challenges in novel EOR technology. This paper focuses on the screening of polymer based on filtration ratio and rheological tests. The Filtration Ratio (FR) test of the polymer solutions has been investigated to check the hydration properties of PHPA polymer by passing it through the nitrocellulose filter paper. The results indicated that FR less than 1.2 ensures proper hydration only if the proper size of filter paper is selected and the filter paper should withstand the pressure. Whereas the presence of monovalent ions slightly increases the FR thus causing the formation of early Filter Cake but can still be used only if FR is less than 1.2. These findings may help the industry to compare wide variety of polymers solutions for a specific well. Only those polymers would be used which passes FR test with little or no filter cake for further rheological tests, thus ensuring proper utilization of available time. [ABSTRACT FROM AUTHOR]

The effect of aging on the properties of paper sized with chitosan, cationic starch, and PVA was investigated under accelerating conditions (90°C and 50% RH). The observations from this study demonstrate that the brightness and pH of papers decrease with an increase in aging time. At each aging time, paper sized with chitosan shows the highest reduction in brightness, whereas decreases in brightness in papers sized with PVA and cationic starch do not show much difference. The results demonstrate that paper sized with any of the polymers gave higher levels of tear index, tensile index, and folding endurance than the control sheet. Statistical analysis indicated that the polymers used in this experiment have a statistically significant effect on the folding endurance of sized paper that was highest in the cases of PVA and chitosan. [ABSTRACT FROM AUTHOR]

The binder plays an important role in transmitting loads and maintaining the stability of paper-based friction materials. Four kinds of binder-based carbon fiber–reinforced paper-based friction materials were prepared. The effects of the ratio of the liquid nitrile butadiene rubber (LNBR) and phenolic resin (PF) content on the friction and wear properties were investigated. It was found that the dynamic and static friction coefficients would increase with an increase in LNBR content. When the content of PF and LNBR was kept at 20 wt%, the friction materials had lower wear rates and better thermal stability. These phenomena indicated that a certain amount of rubber in the binder could improve the friction and wear properties of the friction materials. [ABSTRACT FROM AUTHOR]

Polymers are widely used in the manufacture, converting, and end-use of paper products where the quality of polymer adhesion is important at both paper and fiber levels. This article reviews a number of relevant theories of polymer adhesion, and such adhesion phenomena as revealed in recent investigations of the adhesion between polymer thin films and paper surfaces, the adhesion of polymer molecules to cellulose fibers, and surface forces measurements between model cellulosic surfaces. It is concluded that molecular adhesion and viscoelasticity of cellulose-polymer-cellulose joints play primary roles in the paper strength, which can be tailored by a rational design of polymer additives either as strength enhancers for strong paper products or debonding agents for soft paper tissues. [ABSTRACT FROM AUTHOR]

Fouling of a negatively charged polyurethane surface by substances typical of those occurring in the wet end of paper machines was studied by QCM-D and AFM. The aim was to evaluate the influence of surface forces, adsorption kinetics, viscoelasticity, and morphology of the adsorbed layers on the fouling process, which is discussed in terms of three steps:(1)contacting of deposits with the surface,(2)adherence of the deposits to the surface, and(3)ability of the adsorbed layer to collect further deposits. Substances studied were pitch emulsions, latex, AKD, kaolin and talc dispersions, cationic starch, and other soluble polymers. pH was 5.5–7. Adsorption tendencies depended, as predicted by the DLVO theory, on the ionic strength and valence of simple ions. Kaolin or polystyrene latex adsorbed only above critical salt concentrations. Strongly coagulated pitch emulsions(large aggregate size)adsorbed to a lesser degree than weakly coagulated emulsions(smaller aggregate size), apparently due to the slower diffusion rate of the larger aggregates. [ABSTRACT FROM AUTHOR]

Paper sludge-polypropylene (PP)–ethylene propylene diene terpolymer (EPDM) composites were developed in this study. The paper sludge was used as a filler in PP/EPDM blends, and maleic anhydride-grafted PP (MAPP) and LICA were used as a compatibilizer and a coupling agent, respectively. The mechanical properties, thermal behavior, water absorption, morphology, and the compatibilization mechanism of the composites were investigated. The better mechanical properties (e.g., tensile strength and tensile modulus) and lower water absorption with the addition of both compatibilizer and coupling agent were due to the improvements in the wetting of filler surface and better filler matrix interaction of composites as evidenced from scanning electron microscopy studies. It was found that paper sludge acted as a nucleation agent with the presence of MAPP and LICA. The addition MAPP and LICA also increased the crystallization of PP and thermal stability of PP/EPDM/PS composites. The interaction between MAPP and LICA with paper sludge was confirmed with FTIR. [ABSTRACT FROM AUTHOR]

A simple field method which allows the determination of fluoride in drinking water with a small handheld instrument called Arsenator was developed. Arsenator is a commercially available instrument which was used successfully for reliable determination of arsenic. In the proposed method the functionality of the Arsenator which is based on a photometric measurement of a spot on the reagent paper is expanded to analyse fluoride. A polymeric aluminium complex of 5-(2-carboxyphenylazo)-8-hydroxyquinoline (LH2) has been prepared as a new specific reagent for fluoride. Job's method of continuous variation was adopted for the determination of the composition of the coloured complex, which was further characterized by UV-VIS spectroscopic studies. The molar absorptivity of the complex formation is 8.48 × 103 L mol−1 cm−1at 410 nm. The coloured complex reacts with fluoride on an impregnated paper where its colour changes are dependent on the concentration of fluoride in water samples. The change in the colour was measured using the Arsenator. The method allows a reliable determination of fluoride in the range 0.3 to 2.0 mg L−1. Further spectophotometric determinations of fluoride in drinking water were also studied. The determination is based on the reaction of aluminium complex with fluoride in the examined samples. Beer's law is obeyed in the range 0.3 to 2.0 mg L−1of fluoride at 495 nm. Sensitivity, detection limit and quantitation limit of the method were found to be 0.251 ± 0.007 µg−1 mL, 0.1 mg L−1and 0.3 mg L−1, respectively. The optimum reaction conditions and other analytical conditions were evaluated. The effect of interfering ions on the determination is described. There is no interference by nitrate or chloride. Sulphate interfered only at high concentrations which are not expected in drinking water. [ABSTRACT FROM PUBLISHER]

In this study, the effect of heat treatment on barrier and functionality of polyolefin-coated papers was investigated. The aim was to find the optimal improvements on barrier without losing the applicability of the materials due to physical damages. The results of the study proved considerable improvement in barrier characteristics of the structures. Both water vapor and oxygen transmission rates of LDPE-coatings decreased linearly following the set-temperature until 200°C. At this point, the treatment caused a continuing decrease in oxygen transmission achieving 10 × lower transmission levels than the untreated structure, whereas moisture transport faced corresponding but lower increase. This was considered to be caused by the difference in diameter of the H2O and O2 molecules; the smaller water molecules are able to penetrate between spherulites, whose size increased due to higher treatment temperature followed by cooling. [ABSTRACT FROM AUTHOR]

In order to apply a polymer-based aqueous biphasic system (ABS) extraction to the paper pulping process, the partitioning behavior of six model lignin species (Indulin AC, Indulin C, Reax 85 A, Reax 825 E, Polyfon T, and Alkali lignin) were studied in PEG-2000/NaOH ABS prepared from stock solutions of 40% (w/w) PEG-2000 and increasing concentrations of NaOH. In a given salt concentration, the distribution ratios increase in the order Polyfon T < Reax 825 E < Reax 85 A < Indulin C < Alkali lignin < Indulin AT due to the degree of sulfonation. In both chemical pulping and Organosolv pulping, temperatures in excess of 120 °C are needed to solubilize the lignin from the cellulose, however, the availability of data on all relevant ABS system parameters, especially phase diagrams under process conditions, is limited. Phase diagrams of PEG-2000/(NH4)2SO4 at higher process temperatures have thus been measured. The partitioning of phthalic acid was studied in order to understand temperature effects not only on system composition, but also on phase partitioning. [ABSTRACT FROM AUTHOR]

The wetting behavior of a series of polymer-coated papers has been studied. Different ways of determining the acid–base properties of the polymers are presented. The well-known van Oss–Chaudhury–Good (vOCG) bi–bi polar model is compared with more simplified mono–bi polar and mono–mono polar models. The effect of surface roughness on the wetting was also studied with atomic force microscopy. The overall wetting of each probe liquid was evaluated by calculating the work of adhesion to the polymer surfaces. It is shown that ethylene glycol and water may be considered as mono polar liquids, which simplifies the original vOCG-model. It is also shown that in most cases the surface energy values are in the same range when using both the complex bi–bi polar approach and the simpler mono–mono polar approach. The different polymers used are found to be of a predominating basic character. [ABSTRACT FROM AUTHOR]

The particle morphology of impact polypropylene was examined experimentally in order to understand how the rubber phase produced in the second step of! the polymerisation is distributed inside the growing polymer particles, and how the quantity of rubber produced influences the overall morphology of the final product. It was found that the rubber can pool on the surface of the growing particles, but that this pooling is not uniform. In addition, it was observed that the rubber phase does not [ABSTRACT FROM AUTHOR]

The mechanical properties of woven natural fiber reinforced polymers additively manufactured through Laminated Object Manufacturing (LOM) technology are investigated in this paper. The benefits of both the material and manufacturing process were combined into a sustainable practice, as a potential alternative to traditional synthetic composite materials made from nonrenewable crude oil with limited end-of-life alternatives. Woven jute fiber reinforcements are used to strengthen both synthetic and bio- thermoplastic polymers in creating highly biodegradable composite structures. Such materials, as one of the prospective alternatives for synthetic composites, can be used in many engineering fields such as automobile panels, construction materials, and commodity and recreational products including sports and musical instruments. A LOM 3D printer prototype was designed and built by the authors. All woven jute/polymer biocomposite test specimens made using the built prototype in this study had their mechanical (both tensile and flexural) properties assessed using ASTM test standards and then compared to similar values measured from pure polymer specimens. Improved mechanical characteristics were identified and analyzed. Finally, SEM imaging was performed to identify the polymer infusion and fiber-matrix bonding conditions. [ABSTRACT FROM AUTHOR]

Paper is one of the most important inventions in the history of civilization, and it is an essential commodity to all people in the world. The fact that we make ubiquitous use of a score of paper products makes it easy to underestimate its value and significance. This review is intended to put into perspective the dispersion science involved in papermaking and to describe how our understanding of key processes has evolve since its conception, approximately 2000 years ago, from art to science. Paper is formed from a slurry of fibers and much smaller particles that are often called“fines” and other chemical additives. Ahead of the paper forming process the slurry is subjected to a series of steps, including treatment with polyionic species and passage through unit operations that impose shear forces on the papermaking suspension. These steps alternately disperse the solids apart or re-gather them back together. The overall process is optimized to achieve a highly uniform product, while at the same time achieving high efficiency in retaining fines in the sheet and allowing water to drain relatively quickly from the wet paper as it is being formed. As we approach the 1900-year anniversary of the first detailed account of the papermaking process, it is the goal of this review to explore the scientific principles that underlie the art of papermaking, emphasizing the state of dispersion of the fibrous slurries during various stages of the manufacturing process. Some concepts that arise out of the experience of papermakers have potential applications in other fields. [ABSTRACT FROM AUTHOR]

This paper describes the analysis of a fibre-on-fibre abrasion test, in which two adjacent lengths of fibre contact one another in a twisted geometry. Consideration is given to the various factors contributing to the mechanical actions occurring during the test. Results are presented of a preliminary study, using this fibre-on-fibre abrasion technique, of the progressive changes accompanying the oxidative stabilisation of polyacrylonitrile (PAN) fibres in a set of partially-oxidised commercial samples. The effects of abrasion on the fibres are also examined using scanning electron microscopy (8EM). The analysis predicts that applied tension and level of twist should play major roles in determining the severity of the test, and this is borne out by experiment. Considering the influence of the oxidative treatment on PAN fibres, it is concluded that the abrasion life generally decreases as stabilisation proceeds. The SEM results indicate a transition from plastic to brittle behaviour, which can be accounted for in terms of simple structural models of FAN and oxidised PAN fibres. [ABSTRACT FROM AUTHOR]

Hypochlorite anion has been widely used as a bleaching and disinfecting agent in daily life. Selective and sensitive identification ofOCl-ions from water is very important for researchers. For this purpose, monomeric (NPh), and polymeric (PNPh-Peg) novel fluorescent sensors have been established for the specific and excellently unique sensors that exhibit selective characteristics like excellent resistance to bleaching and a high fluorescence brightness. A multi-functional random polymer (PNPh-Peg) with ICT (intramolecular charge transfer) active para–amino phenol functionality and reactive oxygen species (ROS) responsive, PEG attached are readily prepared via ROMP (ring-opening metathesis polymerization).: An ICT-active random polymer (PNPh-Peg) exhibited an unexpectedly strong cyan blue emission in a water medium compared to that in other common organic solvents, which was dramatically increased by adding a trace amount of NaOCl.: Incorporating PEG moiety in the polymeric backbone increases the water solubility of a copolymer, and the ROS-responsive groups make the polymer a good ROS scavenger. Upon oxidation of the phenol group into carbonyl, both the monomeric (NPh) and polymeric (Norp-PEG oh) sensors showed a selective, noticeable, unusual fluorescence turn-on response towardsanalyteOCl-ions with a very fast response (within three minutes). The detection limit (59.14 nM) and (126.93 nM) were calculated for monomeric and polymeric sensors, respectively. This was a selective, specific oxidation reaction of the completely water-soluble random polymeric sensor (PNPh-Peg) for hypochlorite anions and can be applicable for quantitative measurement of aqueous OCl-. This ICT-active random polymeric molecule (PNPh-Peg) can also be used as a fluorescent sensor for unique OCl- detection from contaminated water by preparing a sensor-coated paper strip. Thus, these multi-functional monomeric (NPh) and polymeric (PNPh-Peg) sensors are anticipated to apply to the environment. [ABSTRACT FROM AUTHOR]

Electronic readers that use rugged flexible substrates potentially offer very attractive characteristics (low-cost processing, lightweight, mechanical flexibility, etc.) and could expand the explosive growth of e-reader devices. In this paper, we demonstrate electrowetting (EW) devices fabricated on flexible substrates, includ-ing paper, polymers (plastics), and metal foils and sheets. EW devices on some of the flexible substrates exhibit characteristics very close to those of conventional EW devices on glass substrates. Prototypes of flexible EW arrays on plastic substrates are demonstrated to switch reversibly by applying a low voltage difference (20 V). The array operation is maintained even when the display is mechanically flexed. These results indicate the promise of flexible EW devices for mobile and other devices, including video rate flexible e-paper. [ABSTRACT FROM AUTHOR]

The dye binding characteristics of 8 mol% NNMBA‐crosslinked polyacrylamide‐supported amine is investigated with Rose Bengal (RB), Methyl Orange (MO), Methylene Blue (MB) and Methyl Red (MR). The influence of the concentration of dye solution on dye binding, time course of dye binding and characterization were explored. It is observed that binding is higher in the case of Rose Bengal and dye binding depends on the polarity, as well as the size of the dye molecule. The photooxidation property of polymer bound RB was investigated towards the oxidation of benzoin to benzil. RB bound polymer acts as an efficient heterogenous photooxidizing agent. [ABSTRACT FROM AUTHOR]

Polymers, with various advantages including lightweight, low cost, flexibility and ease of processing, are popular choices for thermal management in flexible electronics, photovoltaics, fuel cells, etc. In this perspective, we review the recent progress of developing uniaxial thermally conductive polymers and three-dimensional polymers with high thermal conductivity, discuss new opportunities in applying machine learning methods to search for thermally conductive polymers, and finally point out current key challenges and future directions in simulations and experimental measurements. The useful insights in this perspective can guide the rational design of thermally conductive polymers for advanced thermal management. This paper delineates the advantages and recent progress of pristine polymers with high thermal conductivity and provides significant insights on future directions in the simulations and experimental measurements of thermally conductive pristine polymers. [ABSTRACT FROM AUTHOR]

Exposing Pseudomonas aeruginosa biofilm grown on the inner surface of Teflon and silicone tubes to UVC light (265 nm) from light emitting diodes (LED) has previously been shown to substantially reduce biofilm growth. Smaller UVC fluencies were required to disinfect Teflon tubes compared to silicone tubes. Light propagation enhancement in tubes can be obtained if the refractive index of the intra-luminal saline solution is higher than that of the polymer. This condition is achieved by using Teflon tubes with a low refractive index (1.34) instead of the polymers with a high refractive index (1.40-1.50) normally used for tubing in catheter production. Determining whether or not UVC light exposure can disinfect and maintain the intra-luminal number of colony forming units (CFUs) at an exceedingly low level and thus avoid the growth and establishment of biofilm is of interest. The use of UVC diodes is demonstrated to be a preventative disinfection treatment on tubes made of Teflon, which enhances the UVC light propagation, and on tubes made of a softer material, ethylene vinyl acetate (EVA), which is suitable for catheters but much less suitable for UVC light propagation. Simulating an aseptic breach (∼103-104 CFU ml-1), the UVC disinfection set-up was demonstrated using tubes contaminated with planktonic P. aeruginosa. After the tubes (10-20 cm) were inoculated with the bacterial solution for 3 h, they were emptied and filled with saline solutions (0.9-20%). Next UVC fluencies (0-21 mJ cm-2) were applied to the tubes 3 h after inoculation. Colony counts were carried out on liquid samples drawn from the tubes the first day after UVC treatment and liquid and surface samples were collected and analyzed 3-4 days later. A fluence of approximately 1.0 mJ cm-2 was noted as being sufficient for no growth for a period of 3-4 days for the Teflon tubes. Determining the fluence threshold for the EVA tubes was not possible. Almost all of the UVC-treated EVA tubes were disinfected simply by filling the tubes with a saline solution. Direct UVC treatment of the contaminated EVA tubes revealed, however, that a fluence of 21 mJ cm-2 killed the bacteria present in the tubes and kept them disinfected for a period of 3-4 days. [ABSTRACT FROM AUTHOR]

Copyright of Studies in Conservation is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The migration of chemicals from food contact materials into foods is an important issue in food safety. The assessment of materials compliance with regulations includes migration monitoring for many monomers and additives. However, it is recognized that predictive mathematical modelling can be used in many cases, to avoid or to reduce the effort on migration experiments. This article reviews the approaches followed to apply mathematical models to migration, particularly the models used, the approaches to estimate model parameters, and the systems used to experimentally validate the models. Conclusions on the issues requiring further research are drawn. [ABSTRACT FROM AUTHOR]

In this paper, a new three-dimensional network coordination polymer {[Co(TPTC)(HBPDPE)2·2H2O]·3H2O}n [[[(1:1′:4′,1″-terphenyl)-3,3″,5,5″-tetracarboxylic cobalt (II)] dipyridine dihydrate] trihydrate] (Complex 1) was generated under solvothermal synthesis by rigid conjugated ligand H4TPTC ([1:1′:4′,1″-terphengl]-3,3″,5,5″-tetracarboxylic), V-shaped BPDPE (4,4′-bis (pyridyl) diphenyl ether) and Co(II) ion. In complex 1, the neighboring Co(II) ions are linked by deprotonated TPTC4- to achieve a 1D zigzag chain [Co(TPTC)(HBPDPE)2]n, then the adjacent [Co(TPTC)(HBPDPE)2]n chains linked each other by various H-bondings to extend the structure from 1D chain to 3D network. Complex 1 has excellent fluorescence sensing performance and exhibits high sensitivity and selectivity for detecting 2,4,6-trinitrophenol (TNP), the quenching constant Ksv is up to 2.08 × 105 M−1 along with the correlation coefficient R2 of 0.993. Furthermore, the quench mechanisms of this Co-MOF as a sensor to detect nitro- aromatic explosives were studied as well. A new three-dimensional coordination polymer {[Co(TPTC)(HBPDPE)2·2H2O]·3H2O}n (1), constructed by 1D zigzag chains and H-bondings interactions, was synthesized under solvothermal condition by a rigid conjugated ligand H4TPTC ([1:1′:4′,1″-terphengl]-3,3″,5,5″-tetracarboxylic), BPDPE (4,4′-bis (pyridyl) diphenyl) and Co(II) ion. Complex 1 has excellent fluorescence sensing performance for detecting Nitroaromatic explosive (NAE) 2,4,6-trinitrophenol (TNP), the quenching constant Ksv is up to 2.08 × 105 M−1, and the quenching mechanism was studied as well. [ABSTRACT FROM AUTHOR]

The coupling of surfactant and polymer can weaken their shortcomings, improve drag reduction rate, and enhance the stability of drag reduction. This paper takes the cationic surfactant octadecyl trimethyl ammonium chloride and the nonionic polymer polyethylene oxide as the research objects, and uses the coaxial cylinder system of Anton Paar MCR102 to study the synergistic drag reduction of cationic surfactant and nonionic polymer. The experimental results show that cationic surfactants and nonionic polymers has obvious synergistic drag reduction. Compared with 800 ppm OTAC/NaSal solution or 40 ppm PEO solution, the drag reduction increases by 61.49% and 19.78%, respectively. Moreover, the drag reduction rate of the mixed solution is not monotonically increasing with the surfactant concentration. When the OTAC/NaSal concentration reaches polymer saturation point of 1200 ppm, the drag reduction rate of the mixed solution reaches the maximum value of 14.09% and the drag reduction rate increases by 34.15%; when the concentration of OTAC/NaSal is less than 1200 ppm, the drag reduction rate increases with the increase of the concentration of cationic surfactant; however, when the concentration of OTAC/NaSal is greater than 1200 ppm, the drag reduction rate is basically stable. In addition, the shear resistance of the mixed solution is significantly enhanced. [ABSTRACT FROM AUTHOR]

In this paper, a novel viscoelastic constitutive model which can reflect the phase transformation mechanism of multi-shape memory polymer (M-SMP) is established. In this model, M-SMP is regarded as an inhomogeneous body composed of different phases, and the rheological representations of each phase are established based on the viscoelastic mechanics theory. Combined with the level set method, the conversion relationships of each adjacent two phases of M-SMP are established, and then the relationships between each phase are obtained. The constitutive model is used to simulate the thermodynamic behavior of dual-shape memory polymer (D-SMP) and triple-shape memory polymer (T-SMP), and the simulation results are compared with the experimental results and models of relevant literature. Meanwhile, the shape memory behaviors under different correlation rates are studied and analyzed considering the influence of rate correlation. The results show that the model can describe the thermodynamic behavior of M-SMP more accurately and effectively, and in shape memory process of M-SMP, there is a strong rate correlation here. The model can provide a theoretical basis for the engineering application of M-SMP. [ABSTRACT FROM AUTHOR]

In recent years, significant changes have occurred in the field of three-dimensional printing (3D-printing) and it has been applied both in the production of prototypes and in regular production in the following sectors: architecture, construction, automotive, aircraft, biotechnology, fashion, etc. Different technologies for 3D-printing are proposed. Between them, the technology FDM (Fused Deposition Modelling) has the greatest application in the industry due to the low cost and simplified operations. This technology is suitable for 3D-printing of various polymers (PET, ABS, PLA, PETG, etc.), which after preliminary treatment can be metallised by electroless deposition in order to obtain an even metal coating. The present paper describes investigations of some properties of nickel or copper coatings, electroless deposited from two kinds of solutions on 3D-printed and on cast under pressure ABS samples. For deposition of electroless nickel or copper coatings with good adhesion, the influence of the pre-treatment operations was also evaluated in both cases upon deposition on 3D-printed ABS samples with different resolutions (0.8 or 0.25 mm,) and on cast under pressure ABS samples. The thickness of the deposited layers was determined gravimetrically; the morphology and the elemental composition of the layers were examined by SEM or EDS, respectively; the surface roughness of the ABS samples was measured by AFM, and the adhesion of the metal layers was evaluated by a standard test with an adhesive tape (type Test-Method ASTM D 3359-83). [ABSTRACT FROM AUTHOR]

In the past five decades, many new types of polymers, containing nitrogen and phosphorus atoms as a significant part of the polymer backbone, have been synthesized. This paper reviews the developments in the field of polyphosphazenes and their applications. In this paper, synthesis, characterization, functionalization and practical applications of polyphosphazenes are described. [ABSTRACT FROM AUTHOR]

Proteins and peptides are rapidly developing pharmaceutical products and are expected to continue growing in the future. However, due to their nature, their delivery is often limited to injection, with drawbacks such as pain and needle waste. To overcome these limitations, microneedles technology is developed to deliver protein and peptide drugs through the skin. One type of microneedles, known as dissolving microneedles, has been extensively studied for delivering various proteins and peptides, including ovalbumin, insulin, bovine serum albumin, polymyxin B, vancomycin, and bevacizumab. This article discusses polymer materials used for fabricating dissolving microneedles, which are poly(vinylpyrrolidone), hyaluronic acid, poly(vinyl alcohol), carboxymethylcellulose, GantrezTM, as well as other biopolymers like pullulan and ulvan. The paper is focused solely on solvent casting micromoulding method for fabricating dissolving microneedles containing proteins and peptides, which will be divided into one-step and two-step casting micromoulding. Additionally, future considerations in the market plan for dissolving microneedles are discussed in this article. [ABSTRACT FROM AUTHOR]

In this paper, a Serratia marcescens fibrinolytic protease KD was covalently immobilized onto the electrospun prepared glutaraldehyde (GA)-functionalized chitosan/cellulose acetate membrane nanofibres. Enzyme immobilization has been optimized at some conditions such as different GA values, different crosslinking times, different enzyme and pH values, and different times of immobilization. Results exhibited that the optimized immobilization conditions were obtained in 5.0% GA, after 4 h of crosslinking time, after 8 h immobilization time, using 210 mg protein/g support at pH 9.0. Based on these optimal conditions, the best encapsulation yield (EY) and activity recovery (AR) were obtained about 85% and 121.3%, respectively. The immobilized protease showed a 52% enhancement in protease activity than the free protease in pH 10. Furthermore, results displayed that the Vmax values of free and immobilized enzymes towards casein were gained 0.491 and 0.79 µmol/min, respectively. Moreover, the activity of immobilized protease was retained about 75% after incubation at 60 °C for 180 min at pH 9.0, in which the free protease only preserved about 20% of its primary activity. Results exhibited that the protease-NFs kept nearly 73% of its initial activity after three weeks of storage, while the free protease retained about 20% of its initial activity at the same condition. Results showed that the free protease exhibited 31% clot lysis, whereas the immobilized enzyme exhibited 39% clot lysis. The highest hydrolysis value of both proteases was done 17 and 48% after 4 h at 40 °C, respectively. These results indicated that Chit/CA electrospun nanofibres are excellent membranes for protease immobilization with high application in the digestion of protein waste. [ABSTRACT FROM AUTHOR]

Flotation has been used to treat coal over the last century. However, the conventional flotation condition can hardly be applied to ultrafine coal slime (UCS). An alternative combined method, which has the potential to improve UCS separation efficiency, is using high-shear pretreatment (HSP) and polymer regulator. Presented in this paper are the findings from an investigation into the flotation performance and aggregate characteristics of UCS with the assistance of HSP and polyvinylpyrrolidone (PVP). Electrokinetic, laser particle size, and rheology experiments were employed to analyze the influence of HSP and PVP on ultrafine particles. The UCS studied has a high ash content of 53.62%. The flotation results were analyzed through flotation efficiency and selectivity indexes. The results show that the flotation concentrate has less gangue entrainment and high combustible recovery, low ash content (12.74%) and higher flotation efficiency (66.26%) were obtained. Moreover, the results of flotation kinetics illustrate the advantage of using PVP, which improves the cumulative combustible recovery and flotation rate. The introduction of HSP was conducive to the improvement of separation selectivity. These findings provide fundamental insights into the effect of HSP and PVP on ultrafine particles and offer an effective technique for the enhancement of UCS flotation. [ABSTRACT FROM AUTHOR]

Drug-eluting stents (DES) are the best choice of the current era to open the occluded arteries. Its success depends upon the concentration of the drug and overall release kinetics, which in turn is subjected to the polymeric drug carrier and mechanism of drug release at the target area. Each generation of DES possess different characteristics based on different aspects i.e., polymer type, coating layer thickness, and drug concentration have been discussed. This review paper discusses all the polymers utilized in DES systems and their release profiles when combined with multiple drugs for the treatment of coronary heart disease. Drug-coated metal stents are used to support and improve the quality of life of patients with cardiovascular diseases. This review describes the properties of drug-eluting stent from different generations and challenges they offered. Nature of polymeric drug carriers affects the inflammation, lesion healing, rate of restenosis, and thrombosis. Ongoing research in DES technology aims to avoid the challenges offered by non-erodible polymeric drug carriers. Third-generation DES utilizes PLA-based polymers which are biocompatible, flexible, and erodible. Bioresorbable DES is future of DES technology; however, it is still in primitive stages and overcoming the issues of mechanical strength and corrosion. [ABSTRACT FROM AUTHOR]

During the moulding of polymeric pieces, the important temperatures involved, and the gases produced by decomposition of components from the polymer can induce corrosion on the working surface of the steel mould. Polymers can also stick to the mould surface, being their separation (demoulding) one of the critical aspects in their processing. Demoulding agents typically used in this process are expected to contribute in some extend to protect the mould against corrosion. In this work, hybrid sol–gel technology for anti-adherent coatings presented in previous papers is extended to formulations doped with different metallic precursors of proven chemical and wear resistance such as Zn, Ti, and Zr, with the aim to increase the corrosion resistant at the same time that keep good demoulding properties. Different synthetic routes one-pot or two components were followed depending on the doped agent. Sol–gel formulations were applied onto steel substrates by controlled dip coating technique, resulted in ultra-thin films of ∼0.15 µm, being capable to protect micro texturized steel moulds. Hardness of these films was superior (10H) to those formulations with fluorosilane and PDMS used as reference. Corrosion protection was evaluated obtaining good results in both polarization resistance and corrosion rate for Zn (5232 Ω × cm2, 0.08 mm/year), protecting the bare steel up to 6.5 times more in terms of annual corrosion, followed by Zr and Ti. Their behaviour as anti-adherent coating was also discussed and compared with fluorosilane and PDMS-based coatings. [ABSTRACT FROM AUTHOR]

In recent years, additive manufacturing technology has been highly focused on its strong capability in complex geometry manufacturing and great suitability for customised product fabrication. Researchers have recognised the key role of additive manufacturing in leading the next-generation manufacturing, and have conducted extensive research from different aspects, including product design, process development, material modelling and many others. Several design-for-additive manufacturing methods have been proposed, specifically about design, and different computer-aided programmes have been developed, such as geometric modelling-based design, bio-inspired design, evolutionary algorithm-driven design and topology optimisation. However, authors have observed that many of these methods are named 'design for additive manufacturing' without specifying the exact additive manufacturing process. This could be problematic since a general design method cannot reflect the best practice given a specific additive manufacturing process. In this review paper, material extrusion polymer 3D printing is focused specifically. The motive of this paper is to conduct a literature survey about design methods for material extrusion polymer 3D printing, summarising the state of the art and pointing out the underdeveloped research topics; more importantly, some general design-for-additive manufacturing methods will be discussed, especially for their adaption to the material extrusion process. [ABSTRACT FROM AUTHOR]

This paper presents the effectiveness of the copper (Cu)-based coaxial through silicon vias (CTSVs) to reduce crosstalk noise and propagation delay. In the proposed CTSVs, the polymer liners are used as insulating material which cancels the crosstalk functional failures. The impacts of the proposed CTSVs on the electrical performance are noticed for different parameters and properties of the material. Simulations of the proposed CTSVs are executed using the standard HSPICE and SYMICAD tools. The results indicated that the effects of crosstalk are reduced using the polymer liners instead of silicon dioxide (SiO2) liners in the proposed CTSVs. The electrical performances of the proposed CTSVs are investigated for various thicknesses of Cu and BCB. Furthermore, a comparative study has been carried out for the SiO2 and benzocyclobutene (BCB) liners. It is observed that BCB liner-based CTSVs crosstalk noise and delay values are reduced by up to 25.06% and 27.8% compared to the SiO2 liner-based TSVs. [ABSTRACT FROM AUTHOR]

A new generation of advanced composite materials has recently emerged through the use of Carbon Nanotubes (CNTs) as the reinforcing constituent in polymer matrix. In this paper, the dynamic response of polymer sandwich beams with functionally graded face sheets subject to two successive harmonic moving loads has been studied. Three different patterns of CNT's distributions for the face sheets have been investigated: Uniform Distribution (UD), Symmetrically Functionally Graded (SFG) distribution, and Unsymmetrically Functionally Graded (USFG) distribution. A thorough study on the effects of velocity, position, excitation frequency, and the phase angles of loads has been carried out using the Radial Point Interpolation Meshfree (RPIM) method based on the 2D theory of elasticity. The SFG is found to result in the highest stiffness of all three distribution patterns. Increasing the volume fraction of the reinforcement is seen to have resulted in an increase of around 33% in the flexural rigidity of the SFG beam. Also, decreasing the frequency is seen to have suppressed the deflection of the USFG type up to 90%. The current research presents a reliable computational framework to help provide an insight into the design of an optimum sandwich structure subject to a complicated state of loading. [ABSTRACT FROM AUTHOR]

Dust palliatives are commonly used when airborne dust is problematic. Dry soils are treated with a mixture of polymers, such as butyl acrylate vinyl acetate (BA–VA), emulsified in water. Eventual spread through surface runoff or leaching may transport palliative away from the application area. This paper reports a novel method developed for the determination of BA–VA using gel permeation chromatography (GPC) and nuclear magnetic resonance spectroscopy (1H NMR) to provide qualitative and quantitative measurements allowing further investigation of polymer-based soil palliatives. The results showed that the average specific refractive index increments (dn/dc) for BA–VA copolymer in two dust palliatives were 0.055 and 0.038 mL/g. The masses of extracted BA–VA were 1400 and 2900 mg from these products. The corresponding limits of quantification (LOQ) for the extracted BA–VA polymer using a refractive index (RI) detector were 11.63 and 17.04 µg, respectively. [ABSTRACT FROM AUTHOR]

The free energies of mixing a series of water-soluble polymers with cellulose were calculated using the UNIFAC (universal functional group activity coefficients) algorithm, and the results were correlated with measurements of polymer/cellulose adhesion. The more negative the minimum free energy of mixing, the greater the measured adhesion. Adhesion was quantified by single-lap shear test in which regenerated cellulose films were laminated with aqueous polymer. The results are relevant to the use of adsorbed water-borne polymers to strengthen cellulose fiber–fiber bonds in paper. The calculations did not anticipate the exceptional strength-enhancing properties of carboxymethyl cellulose, nor did they predict molecular-weight effects. Nevertheless, the approach may have utility as a general tool to relate polymer chemistry to adhesion performance. [ABSTRACT FROM AUTHOR]

In this paper, we reported a polymer stabilised isotropic phase liquid crystal (PSILC). The influences of different content of chiral dopant and polymer monomer on PSILC were studied. Adding the proper proportion and total content of polymer monomer TMPTA and C12A into liquid crystal with 1.0 wt.% chiral dopant R5011, and UV photo-polymerisation at the isotropic phase, we obtain the Kerr constant greater than 10 nm/V2, hysteresis less than 2.0% and fast response in PSILC. [ABSTRACT FROM AUTHOR]

The quality of borehole sealing is closely related to the sealing materials. As a kind of sealing material, how polymer materials improve the sealing quality has not been deeply analyzed. This paper based on the analyses of the dynamic contact state between polymer material and borehole wall, taking borehole, polymer material and their contact surface as the research object, this paper analyzes the changes of air leakage channel after sealing, the internal particles of foaming material, and the structure characteristics of contact surface. From multi-angle to obtain the sealing mechanism of polymer material. The results are: (1) the reduction rate D equation of the air leakage channel is derived. It positively relates to the expansion support force of sealing material. (2) Polymer materials could reduce the stress and deformation of coal surrounding borehole by 2.3 ~ 4.5% and 15.2% ~ 19.9% respectively, to narrow the air leakage range outside the hole. (3) The unusual structure of polymer foam particles can be well bonded and fixed with the borehole wall, improve the borehole stability, and reduce the air leakage inside the hole. (4) Polymer sealing material can maintain an average gas concentration of 44.90% within 60 days, not less than 30%, and ensure the extraction effect. [ABSTRACT FROM AUTHOR]

This patent review encapsulates information that could be used as a reference by researchers in the fields of coatings and interfaces, biofabrication, tissue engineering, biomaterials, and biomedical engineering, as well as those especially interested in the formulation of hydrogel coatings. The state has been reviewed by introducing what has been innovated, invented, and patented in relation to hydrogel coatings. A detailed analysis of the patentability of hydrogel applications, such as the coating of medical devices to enhance their clinical performance, has been provided. During a search, 2937 patent documents were found. 2012 was the year with the most patent documents (177). Based on the patent classification, all patent documents and most inventions are intended for biomaterials for coating prostheses characterized by their function or physical properties, such as macromolecular materials, hydrogels, and biologically active materials. Additionally, research based on medicinal formulations with unique physical forms is concentrated in the majority of patents, according to knowledge clusters and expert driving factors. Finally, to demonstrate the innovation trends in hydrogel-based coatings, a selection of relevant patent applications and granted patents is proposed at the end of this paper, along with some examples of commercial products based on the patented technologies. [ABSTRACT FROM AUTHOR]

To ensure the desired mechanical properties of adhesively bonded components, maintaining the prescribed mixing quality, i.e. mixing ratio and evenness, of two-component (2K) adhesives is essential. Although different studies proved that mixing errors may exert a negative impact on the bonding result, there are currently no methods available that would allow for continuous monitoring thereof during inline dosing processes. A way out of associated issues is offered by the Electrical Capacitance Tomography (ECT), which enables practitioners to map spatial material distributions and mixing ratios by measuring the capacitances of different media, including adhesives. Therefore, the aim of the study was to investigate the ECT's potential to be used for 2K mixture quality control. Due to the complexity of the matter, the presentation is split into two papers. In this 1st part, all preliminary experimental and analytical work aiming to determine polymer characteristics, above all permittivity, ε, needed to evaluate whether a respective 2K adhesive may be ECT-monitored is presented. For that, a permittivity measurement device (PMD) was developed, which allows for a fast and efficient determination of adhesive permittivities. Subsequently, the PMD was validated with reference dielectrics and then used to determine the permittivities of the components of 16 commercially available 2K adhesives (epoxies and polyurethanes). Finally, the relationship between permittivity and mixing ratio was investigated for a sub-set of four representative ECT-suitable adhesives. It was found that a wide variety of 2K polymers may principally be controlled by ECT and that the relationship between mixing ratio and mixture permittivity can be described by general analytical theories from the literature. As a result, preliminary experimental effort aiming to assess the adhesive suitability for inline ECT-monitoring could be significantly reduced. The latter experiments will be the topic of the 2nd part of the study. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to demonstrate the easy manufacturing and quick characterization of several microtextured functional surfaces on two transparent thermoplastics of general interest for several industrial sectors. Microtextured polymeric surfaces with special optical, tribological and easy-cleaning properties were manufactured via isothermal injection-molding using laser-microtextured steel mold inserts. For that purpose, conventional injection molding of two chosen amorphous transparent polymers (polycarbonate, PC, and polymethyl methacrylate, PMMA) utilizing laser-microtextured steel inserts was carried out, and a detailed morphological and functional characterization of the injected specimens was conducted later on. We also report on the suitable process conditions for the injection molding of these specimens using design of experiment (DOE) techniques. The analysis of the degree of replication (DR%) on the injected samples shows that mold temperature and injection speed are the most relevant parameters to obtain a successful replication and confirm the viability of conventional injection molding as a processing technique to obtain microtextured functional surfaces in amorphous transparent thermoplastics. The success of the procedure is further checked by the confirmation of the obtained surface functionalities by various standard and self-developed methods. [ABSTRACT FROM AUTHOR]

Polyurethanes are highly sought after polymer materials due to their exceptional properties. These properties can be expanded by including 2-hydroxyethyl salicylate in its chemical structure in order to obtain active polymer materials with anti-inflammatory and analgesic properties. These polymers can be used in the manufacture of footwear, stockings and clothing. Furthermore, in order to improve mechanical properties, glycerol and its derivatives with various hydroxy-aliphatic chains can be incorporated into the polyurethanes. Changing the chemical structure of the hard segment (through chain extender amount and crosslinker's structure) may yield improved or modified properties and uses for these polyurethanes, which can be identified by investigating the structure–property relationships for these materials. The incorporation of a crosslinker with longer hydroxy-aliphatic chains (glycerol ethoxylate (Star-PEG)) has significantly improved the mechanical resistance of the polyurethane. At the same time, Star-PEG-polyurethane preserved its very good properties after a year of outdoor environmental exposure, without exposure to direct sunlight. The inclusion of the salicylate component in the polyurethane hard segments develops new and interesting ways to obtain polyurethane elastomers for biomedical applications. We intend to study in detail the medical properties of these polyurethane materials and their maintenance over time in a future paper. [ABSTRACT FROM AUTHOR]

Additive manufacturing technology brings new revolutionary potential for the development of carbon fiber reinforced polymer composites. Continuous carbon fiber reinforced composites developed using fused deposition modeling technology have the characteristics of high specific strength, high specific modulus, light weight, and flexible design, which is the solution direction for low-cost, rapid, and flexible application of advanced composite materials in the future. In this paper, the preparation of continuous carbon fiber reinforced polymer composites with continuous carbon fibers as reinforcement and thermoplastic/thermoset as matrix, surface modification and their mechanical properties are investigated, the interfacial characteristics and properties of continuous carbon fiber reinforced polymer composites under different pretreatment processes, auxiliary processes and post-treatment processes are studied, and the connection between the micro-morphology and the mechanical properties of this composite is further analyzed. The direction of defect resolution of continuous carbon fiber reinforced polymer composites fabricated by fused deposition technology is provided, and the future development direction is envisioned. [ABSTRACT FROM AUTHOR]

Achilles tendon defect is caused by direct or indirect violence that makes it difficult for the tensile strength of the Achilles tendon to resist external forces. It is characterized by a lack of tissue integrity around the Achilles tendon, local bruising or bacterial infection, and ultimately leads to abnormal gait. This paper reviews the recent research progress of biodegradable polymeric materials in treating Achilles tendon defects at home and abroad, mainly introducing the therapeutic impact on the repair of Achilles tendon defects from materials alone, materials combined with drugs or cells. [ABSTRACT FROM AUTHOR]

The detection and quantitation of bisphenol A (BPA) in the environment and food products has been a subject of considerable interest. BPA, a diphenylmethane derivative is a well-known industrial raw material with wide range of applications. It is a well-known endocrine disruptor and acts as an estrogen mimic. BPA is an environmental health concern and its accumulation in hydro-geological cycles is a matter of serious ecological peril. This review basically assesses various chemically modified electrodes composed of diverse components that have been employed to recognize BPA in different matrices. Electrochemical sensors prepared using graphene materials in combination with metals and polymers for selective detection of BPA have been discussed extensively. The emphasis is on detection of BPA in various samples encountered in routine use such as plastic bottles, receipts, baby feed bottles, milk samples, mineralized water, tissue paper, DVDs, and others. Although research in this field is in the exploratory stage, deeper insights into fundamental studies of sensing systems, fast analysis of real samples and validation of sensors are some of the factors that need major impetus. It is expected that chemically modified electrode-based sensing systems will soon take over as a viable option for monitoring diverse pollutants. [ABSTRACT FROM AUTHOR]

Glass transition temperature (Tg) is one of the most significant thermophysical property which is hard to measure experimentally. With the development of machine learning, many molecular presentation methods and prediction algorithms have been proposed for predicting Tg. However, most descriptors of these algorithms are linear, while the values of molecular descriptors obtained from experiments or simulation software may have nonlinear relationships. General nonlinear machine learning methods are difficult to apply for the super high dimensional characteristics of molecular descriptors. In this paper, molecular descriptors are defined in manifold space and manifold learning is used for dimension reduction. Different from other linear algorithms for selecting molecular descriptors, Locally Linear Embedding (LLE) is utilised to reduce dimensionalities by extracting new features from numerous molecular descriptors. The features with dimensionality reduction are fed to the eXtreme Gradient Boosting (XGBoost) model. This ensemble algorithm is suitable for predicting glass transition temperature due to its high adaptability and nonlinear approximation ability. Genetic algorithm (GA) is adopted for optimising the parameters of XGBoost. The combinatorial approach consists of dimensionality reduction, prediction and optimisation. Experimental results show that the proposed machine learning approach LLE-XGBoost-GA has higher accuracy in Tg prediction of polymers. [ABSTRACT FROM AUTHOR]

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