Search

Phosphorylated fibers offer a broad range of applications, particularly in thermal insulation, notably with wood fibers, provided they exhibit improved mechanical characteristics. Despite encountering challenges in applying traditional papermaking methods, the creation of paper or board sheets with phosphorylated pulp fibers remains a challenge. Findings suggest that phosphorylation-modified fibers show increased roughness. Moreover, in comparison with unbeaten kraft sheets (KF) and thermomechanical pulp sheets (TMP), those made from phosphorylated kraft fibers (PKF), using a cationic coagulant and a flocculant, demonstrate significant enhancements in burst index, break index, and tensile energy absorption by 2.12 times, 1.7 times, and 2.77 times, respectively. Similarly, phosphorylated TMP sheets, prepared with a dual polymeric system (coagulant/flocculant), exhibit improvements of 1.42 times, 1.33 times, and 1.82 times, respectively, in these properties. The study emphasizes the ameliorating effect of cationic polymeric agents on the charge impact of phosphorylated fibers on overall sheet quality, while also highlighting the substantial influence of hot-pressing lignin-containing paper on all determined physical properties. [ABSTRACT FROM AUTHOR]

Information coding, recording, encryption, and decryption are of great importance in the field of anti‐counterfeiting, especially in the current AI information era. Herein, a paper‐like hydrogel composed of solely H‐bonded poly(vinyl alcohol) (PVA) and poly(n‐vinylcaprolactam) (PNVCL), namely VAPN, is developed for multiple ways of encryption and decryption based on chemical‐induced phase separation. It not only exhibits excellent ability of ink absorption and retention by the noncovalent H‐bonds and n−π* interactions and good mechanical strength but also maintains a negligible volume change during the phase separation that is crucial for the information fidelity. Given that the noncovalent interactions are the driving force to trigger the phase separation in the hydrogel, available chemical inks are numerous ranging from small molecules to polymers. Furthermore, together with thermally induced phase separation, the different dynamic processes of the association and dissociation between ink molecules and the hydrogel endow the latter with reversible information recording and self‐erasing, temporary or permanent, and customized encryption and decryption. [ABSTRACT FROM AUTHOR]

Following the circular bioeconomy concept, this work studies the potential of an industrial wastepaper residue as an alternative raw material for dissolving pulp‐grade production. Prehydrolysis‐kraft cooking (PHK), elemental chlorine‐free (ECF) bleaching, and acid‐washing treatments were applied to achieve that aim. Considering the high lignin and hemicellulose content of the raw material, it was submitted to PHK pulping to enhance its cellulose content by removing those components. This processing resulted in a remarkable increase of 84 % in pulp Fock reactivity (from 45.6 % to 84.1 %). The dissolution extension and time in solvent systems LiCl/DMAc and NMMO/H2O were discussed regarding the pulp physicochemical properties. The dissolving pulp produced under this work showed great potential as raw material for textile applications, particularly highlighting the innovative process developed to improve its solubility. [ABSTRACT FROM AUTHOR]

Campylobacter jejuni is recognized as the most common species in the genus Campylobacter that causes foodborne diseases. The main reservoirs harboring C. jejuni are poultry products, which are associated with most illnesses, creating a demand for effective detection methods to achieve point-of-need diagnostics. We developed an easy-to-use, hybrid paper/polymer-based microfluidic device that integrates paperbased DNA extraction, isothermal nucleic acid amplification, and lateral flow detection. Overall, the recombinase polymerase amplification (RPA) reaction was completed in 20 min and demonstrated 100% specificity to C. jejuni, including 2 reference strains and 6 wild strains isolated from the agroecosystem, 9 other Campylobacter subspecies strains, and 11 non-Campylobacter strains. The limit of detection (LOD) was 46 CFU/mL with DNA extracted on the cellulose paper. The sensitivity was reduced to 460 CFU/mL on the integrated hybrid paper/polymer-based microfluidic device. This device could detect C. jejuni spiked at concentrations ranging from 101 to 10² CFU/g in chicken meat after an enrichment of 5 to 10 h. For C. jejuni levels of >10² CFU/g, it managed to confirm positive results immediately, without bacterial enrichment. RPA reagents and primers remained stable on the paper platform at 22°C for 12 h. After lyophilization and storage on paper, the RPA reaction showed consistent sensitivity for 3 days, and the LOD was reduced to 103 CFU/mL when storage was extended to 25 days. The use of this hybrid paper/polymer-based microfluidic device enabled detection of Campylobacter in foods with high specificity and sensitivity, demonstrating its potential as a reliable point-of-need diagnostic platform for on-site conditions due to its low cost, portability, and simplicity. [ABSTRACT FROM AUTHOR]

Historically, the recording of information over paper has always been regarded as the most important factor for maintaining records of human activities and spreading civilization. The present work is focusing to formulate hydride paper polymer sheets (HPPSs) using two fluorescence dyes (4-(2,6-diphenylpyridin-4-yl)-N,N-dimethylaniline) (F1) and (4-(2,6-bis(4-methoxyphenyl)pyridin-4-yl)-N,N-dimethylaniline) (F2) for the production of secure hybrid paper polymer sheets each with a different concentration. Mechanical properties, including tensile strength (MPa), Young's modulus (MPa), elongation (mm), folding endurance, and tear resistance (mN m2/g), were determined. Furthermore, a topographical study was carried out using field emission scanning electron microscopes (FE-SEM). In comparison with native paper and polymer films, HPPSs demonstrated a significant improvement in mechanical properties. The fluorescence behavior of applied dyes was evaluated in both solution and solid states with UV–vis and photoluminescence (PL). The results confirmed that excitation of F1 and F2 dyes occurred at 393 nm and 448 nm and emission at 505 nm and 496 nm, respectively. Additionally, the third concentration (3% w/v) of both dyes was observed in solid state to achieve excellent resolution. In the first image, a note is shown under normal light, and in the second image, a picture is shown of the fluorescent security markings under UV light at 365 nm. Based on the results obtained, it is proven that the developed high stable as well as excellent mechanical security HPPSs can be used for paper-based information security due to their optical properties. Further, the density function theory (DFT) calculation was performed in order to identify the composition of the excited and ground states. According to the results, the N,N-dimethylamine substituent played a crucial role in explaining the extraordinarily high luminescence of F1 and F2. [ABSTRACT FROM AUTHOR]

The materials utilized in paper packaging are derived from natural plant fibers, making them both environmentally friendly and biodegradable. However, traditional paper has been vulnerable to water and oil, which has limited its widespread use. In this research, a low-fluorine acrylate emulsion with a short carbon chain (CNF-C 6 FA) was created by employing carboxylated nanocellulose (TOCNF), dodecyl phenol ethoxylate, and sodium dodecyl sulfate as emulsifiers through semi-continuous seed emulsion polymerization. When combined with a specific amount of polyvinyl alcohol, this emulsion is applied to the paper surface to enhance the paper's hydrophobic and lipophobic properties. The findings revealed that paper coated with 5 g/m2 of CNF-C 6 FA achieved an oil-proof grade of 10 and a Cobb value of 13 g/m2, signifying a significant enhancement. It was discovered that TOCNF, acting as an emulsifier, not only maintained emulsion stability through steric hindrance, three-dimensional network structures, or vacancy effects but also conferred exceptional waterproof and oil-repellent properties to the paper. This can be attributed to TOCNF reinforcing the fluorocarbon groups in a directional arrangement, resulting in a dense and smooth coating layer on the paper's surface. The utilization of TOCNF as an emulsifier to produce environmentally friendly, waterproof, and oil-proof paper presents a promising approach for its high-value application. [Display omitted] • Fossil-based surfactants pose health and environmental problems. • Carboxylated nanocellulose (TOCNF) can replace surfactants for emulsifying acrylate polymers. • Carboxylated nanocellulose improves emulsion stability through steric hindrance and three-dimensional network structure. • The paper coated with CNF-C 6 FA has super oil-proof and water-proof dual functions. [ABSTRACT FROM AUTHOR]

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]

This review article covers all types of paper-based humidity sensor, such as capacitive, resistive, impedance, fiber-optic, mass-sensitive, microwave, and RFID (radio-frequency identification) humidity sensors. The parameters of these sensors and the materials involved in their research and development, such as carbon nanotubes, graphene, semiconductors, and polymers, are comprehensively detailed, with a special focus on the advantages/disadvantages from an application perspective. Numerous technological/design approaches to the optimization of the performances of the sensors are considered, along with some non-conventional approaches. The review ends with a detailed analysis of the current problems encountered in the development of paper-based humidity sensors, supported by some solutions. [ABSTRACT FROM AUTHOR]

In this elucidation, we synthesized novel molecularly imprinted polymers (MIPOH1-4) that were used as organic fillers on bagasse pulp to form cellulosic paper sheets, the formation of MIPOH1-4 from the reaction of enaminone 3 with methyl methacrylate monomer in the presence of ethylene glycol dimethyl acrylate and 2,2'-azobisisobutyronitrile. The obtained MIPOH1-4 was confirmed via FT-IR and SEM with different pore sizes. And we noticed that the increase of template 3 increases the hydrogen bond between monomer and template and gave sponge surface of MIPOH4. Furthermore, the computational energies of the template with different monomers utilize DFT/B3LYP/6-31G (d) level to know the stability of polymers and hydrogen bonding between them. So that we applied that in paper manufacture through the adsorption of MIPOH4 as an organic filler on bagasse pulp to form novel cellulosic paper sheets with different concentrations and these sheets which characteristic through FT-IR, SEM, sizing test, tensile strength, and elucidation their antimicrobial activity with theoretical and docking studies. The MIPOH4 and cellulosic paper sheets showed the thermal stability and high tendency of sizability of these paper sheets and concluded the interaction between cellulose fibers of pulp with MIPOH polymer with physical hydrogen bonding. [ABSTRACT FROM AUTHOR]

A novel hydrophilic As(V) ion-imprinted cryogel (IIC) was green prepared by cryogelation in aqueous environment which was coincident with the adsorption condition and can improve the specific recognition performance. The methacrylamido propyl trimethyl ammonium chloride (MPTAC) was selected as the functional monomer and the saturated adsorption capacity of the prepared IIC and NIC were 55.0 mg/g and 29.4 mg/g, and with high imprinting factor of 1.87. Additionally, the prepared IIC showed admirable reusability and high selectivity, and the recovery was in the range 81.2–97.9% with RSD range of 1.9–4.3%, which was similar to the value obtained by hydride generation atomic absorption spectrometry. IIC can be used as solid material for colorimetric detection at the ultraviolet wavelength of 858 nm without color interference of material matrix, in the range 5–200 μg/L (R2 = 0.990) with a detection limit of 0.970 µg/L. Obviously, this synthetic strategy provides a simple, efficient, and green method for the preparation of water-compatible ion-imprinted polymers providing selective separation and detection of trace As(V) in real complex samples. [ABSTRACT FROM AUTHOR]

In recent years, paper has become an essential substrate material for developing different types of sensors, from wearable devices to single‐use test strips and biosensors. In parallel, a polymer‐based toolbox has emerged in order to add additional functions to these paper‐based analytical devices. In this article, examples are compiled from the recent literature showing microfluidic systems based on printing impermeable polymer barriers with different methods as well as the implementation of electrochemical, fluorescent, and colorimetric polymer‐based transducers in paper‐based analytical platforms. Externally actuated or dissolvable polymer valves and reservoirs, analyte concentrators, and separation devices, as well as polymer‐based recognition elements (molecularly imprinted polymers) printed on paper substrates are also reviewed. The search has revealed a plethora of possibilities for developing complex lab‐on‐chip devices implementing different polymer‐based components in them. The ability of patterning these polymers with common printing methods that do not require specialized facilities paves the way for mass producing this kind of advanced paper‐based analytical device. [ABSTRACT FROM AUTHOR]

Hyperuricemia (HUA) has gradually become a public health burden as an independent risk factor for a variety of chronic diseases. Herein, a user-friendly point-of-care (POC) detection system (namely "Smart-HUA-Monitor") based on smartphone-assisted paper-based microfluidic is proposed for colorimetric quantification of HUA urinary markers, including uric acid (UA), creatinine (CR) and pH. The detection limits of UA and CR were 0.0178 and 0.5983 mM, respectively, and the sensitivity of pH were 0.1. The method was successfully validated in artificial urine samples and 100 clinical samples. Bland-Altman plots showed a high consistency between μPAD and the testing instruments (HITACHI 7600 Automatic Analyzer, URIT-500B Urine Analyzer and AU5800B automatic biochemical analyzer) in hospital. Smart-HUA-Monitor provides an accurate quantitative, rapid, low-cost and reliable tool for the monitoring and early diagnosis of HUA urine indicators. [Display omitted] • We proposed a POCT system based on smartphone-assisted paper microfluidics for quantification of urine UA, CR and pH. • The reliability of this work was evaluated by 100 clinical samples, which is of great significance for the diagnosis of HUA. • "Smart-HUA-Monitor" provides a POC tool with high accuracy and good repeatability for the daily monitoring of HUA. [ABSTRACT FROM AUTHOR]

Mineral oil has been widely used as liquid insulation for high voltage equipment such as a transformer. Due to environmental consideration and long-term availability, there are many efforts to find new liquid insulating materials that are environmentally friendly and renewable. Natural ester is among the candidates for those purposes. In order to be applicable, its interaction with the kraft paper as well as its degradation characteristics is essential to be studied. Accelerated thermal aging is a method that typically been used to assess the performance of oil and paper in the laboratory. In this paper, the result of the degree of polymerization (DP), tensile strength (TS), and Fourier transform infrared spectroscopy (FTIR) measurement were done to examine the degradation characteristic of kraft paper. FTIR which expected to be a new nondestructive diagnosis method of transformer insulation is used to determine the changes of the chemical bond of the kraft paper. The results show that moisture content affects the decrease of DP and TS characteristics. Hence, the FTIR measurement of kraft paper shows that the absorption intensity of C=O and C-H bond increase during the aging. Meanwhile, the absorbance intensity of the O-H bond decreases during aging time. Through regression method, it can be shown that the correlation between DP values to the peak absorbance is influenced by oil-paper moisture equilibrium. Exponential regression method is appropriate for high moisture condition and linear regression is suitable for low moisture condition. [ABSTRACT FROM AUTHOR]

In this work, recycled paper sludge (RPS), composed of non-recyclable fibres, was used as a carbon source for bacterial nanocellulose (BNC) production. The biomass was enzymatically hydrolysed with Cellic CTec 2 to produce a sugar syrup with 45.40 g/L glucose, 1.69 g/L cellobiose and 2.89 g/L xylose. This hydrolysate was used for the optimization of BNC fermentation by static culture, using Komagataeibacter xylinus ATCC 700178, through response surface methodology (RSM). After analysis and validation of the model, a maximum BNC yield (5.69 g/L, dry basis) was obtained using 1.50% m/v RPS hydrolysate, 1.0% v/v ethanol and 1.45% m/v yeast extract/peptone (YE/P). Further, the BNC obtained was used to produce composites. A mixture of an amino-PolyDiMethylSiloxane-based softener, polyethyleneglycol (PEG) 400 and acrylated epoxidized soybean oil (AESO), was incorporated into the BNC membranes through an exhaustion process. The results show that BNC composites with distinct performances can be easily designed by simply varying the polymers percentage contents. This strategy represents a simple approach towards the production of BNC and BNC-based composites. [ABSTRACT FROM AUTHOR]

Enzyme-linked immunosorbent assay (ELISA) is widely used for the detection of disease biomarkers. However, it utilizes time-consuming procedures and expensive instruments, making it infeasible for point-of-care (POC) analysis especially in resource-limited settings. In this work, a multicolorimetric ELISA biosensor integrated on a paper/polymer hybrid microfluidic device was developed for rapid visual detection of disease biomarkers at point of care, without using costly equipment. This multicolormetric ELISA platform was built on multiple distinct color variants resulted from the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) and the etching of gold nanorods (AuNRs). The vivid color changes could be easily distinguished by the naked eye, and their red mean values allowed quantitative biomarker detection, without using any sophisticated instruments. When this multicolorimetric ELISA was integrated on a paper/polymer hybrid analytical device, it not only provided integrated processing and high portability but also enabled fast assays in about 50 min due to the unique advantages of paper/polymer hybrid devices. The limit of detection of 9.1 ng/μL of the hepatitis C virus core antigen, a biomarker for hepatitis C, was achieved using this multicolorimetric ELISA platform. This multicolor ELISA analytical device provides a new versatile, user-friendly, affordable, and portable immunosensing platform with high potential for on-site detections of various viruses, proteins, and biomarkers for low-resource settings such as at home, public venues, rural areas, and developing nations. [ABSTRACT FROM AUTHOR]

The aim of this study was the valorization of paper sludge waste from paper industry in designing one-part geopolymer cement using ground granulated blast furnace slag as main precursor. The effects of increasing the amount of paper sludge pretreated with a constant amount of sodium hydroxide (2% of slag) on mechanical strength, heat evolution, setting time and durability were analyzed. The reaction products were characterized using X-ray diffraction and thermogravimetric analysis. The findings showed that paper sludge can successfully be used as a secondary source of calcium carbonate in the one-part (“just add water”) geopolymer. The compressive strength of the cured geopolymer increased with increasing the amount of paper sludge, and the non-reacted sludge acted as a filler. The maximum strength (42 MPa, 28 d) was reached at 18 wt-% paper sludge addition. The main reaction products were calcium aluminate silicate hydrate and hydrotalcite-like cementitious gels. From the perspective of its blast-furnace slag content, strength properties, water absorption and setting time, the one-part geopolymer cement could be classified as a CEM IIIC and Type 32.5N class cement under the European standard EN-197. [ABSTRACT FROM AUTHOR]

Paper spray mass spectrometry has received considerable attentions in recent years due to its simple operation, low cost and without tedious sample pretreatment prior to analysis. However, paper spray ionization (PSI) as a type of electrospray-based ionization source, there are few reports on exploring the ionization performance differences between it and two frequently used electrospray ionization (ESI) and nanoelectrospray ionization (nanoESI). Herein the ionization performance of above three ionization sources was compared systematically by using gasolines, myoglobin, cytochrome c and glycidyl azide polymer (GAP) as samples. According to the obtained results, the ionization performance demonstrated the following trend: PSI

Green liquor dregs wastes coming from pulp and paper production are currently disposed in landfills at a huge cost for industry and the environment. In this work, a novel and more sustainable waste management strategy is proposed. Dregs were used for the first time as fine filler in the production of biomass fly ash-based geopolymeric mortars. The influence of the dregs incorporation amount on the fresh (geopolymer kinetics and mortars workability) and hardened-state (mechanical resistance, water absorption and capillary water absorption) properties of the mortars was evaluated. Although dregs incorporation reduce the flow workability (up to 19%), their presence and amount did not significantly alter the geopolymerization kinetics. Additionally dregs-containing mortars exhibited enhanced tensile (up to 71%) and compressive strength (up to 34%), and lower water absorption in comparison with the reference mortar. These results demonstrate the feasibility of using dregs as fine filler in geopolymers production. Moreover the mortars were produced using mainly biomass fly ash waste as aluminosilicate source which further reduces the environmental impact of the pulp and paper industry. [ABSTRACT FROM AUTHOR]

Information is provided on the properties of technical-purpose papers based on heat-resistant superhigh modulus (SHM) para-aramid fibres containing heterocyclic rings. Various methods of producing such papers are reviewed. The properties of samples of the heat-resistant papers are listed. The results of study and comparison of chemical resistance of the obtained papers are adduced. [ABSTRACT FROM AUTHOR]

This study compares the environmental performance of Mexican banknotes printed on high-durability cotton paper (HD paper) and thermoplastic polymer (polymer) through a life cycle assessment to appraise the environmental impacts from the extraction of raw materials to the final disposal of the banknotes. The functional unit was defined considering the next parameters: 1) lifespan of the banknotes, stablished in 31.5 and 54 months for HD paper and polymer, respectively; 2) denomination, selecting $200 pesos banknotes; 3) a 5 year time frame and 4) a defined amount of money, in this case stablished as the monthly cash supply of an average Mexican household, equaling $12,708 pesos. Accordingly, 121 pieces for the HD paper and 71 pieces for the polymer banknotes were analyzed. The results favor the banknotes printed on polymer substrate primarily because of the longer lifespan of this type of material; however, there is a considerable environmental impact in the stages of distribution, followed by the extraction of the raw materials (crude oil) during manufacturing. Regarding the HD cotton paper, the major impact corresponds to extraction of the raw materials, followed by the distribution of the banknotes. The inclusion of the automatic teller machines (ATMs) in the life cycle assessment of banknotes shows that the electricity required by these devices became the largest contributor to the environmental impacts. Additionally, the sensitivity analysis that the average lifetime of the banknotes is a determining factor for the environmental impacts associated with the whole life cycle of this product. The life cycle stages that refer to the extraction of the raw materials, combined with the average lifetime of the banknotes and the electricity required during the usage stage, are determining factors in the total environmental impact associated with Mexican banknotes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Paper-based electrodes coated with polymers, mimick the lignocellulosic biomass. • Lignin penetrates deeply in the paper as shown by SEM and CV analyses. • The presence of lignin forms a barrier, avoiding a redox probe to reach the electrode. • Ligninolytic enzymes degraded this biomimetic substrate and allowed to recover the signal. Lignin is the most important natural source of aromatic compounds. The valorisation of lignin into aromatics requires fractionation steps that can be catalysed by ligninolytic enzymes. However, one of the main limitations of biological lignin fractionation is the low efficiency of biocatalysts; it is therefore crucial to enhance or to identify new ligninolytic enzymes. Currently, the screening of ligninolytic activities on lignin polymers represents a technological bottenleck and hinders the characterization and the discovery of efficient ligninolytic biocatalysts. An efficient and fast method for the measurement of such enzymatic activities is therefore required. In this work, we present a new electrochemical tool based on lignin-coated paper electrodes for the detection and the characterization of ligninolytic activity. The suitability of this method is demonstrated using a catalase-peroxidase isolated from Thermobacillus xylanilyticus. [ABSTRACT FROM AUTHOR]

Hybrid microfluidic systems that are composed of multiple different types of substrates have been recognized as a versatile and superior platform, which can draw benefits from different substrates while avoiding their limitations. This review article introduces the recent innovations of different types of low-cost hybrid microfluidic devices, particularly focusing on cost-effective polymer- and paper-based hybrid microfluidic devices. In this article, the fabrication of these hybrid microfluidic devices is briefly described and summarized. We then highlight various hybrid microfluidic systems, including polydimethylsiloxane (PDMS)-based, thermoplastic-based, paper/polymer hybrid systems, as well as other emerging hybrid systems (such as thread-based). The special benefits of using these hybrid systems have been summarized accordingly. A broad range of biological and biomedical applications using these hybrid microfluidic devices are discussed in detail, including nucleic acid analysis, protein analysis, cellular analysis, 3D cell culture, organ-on-a-chip, and tissue engineering. The perspective trends of hybrid microfluidic systems involving the improvement of fabrication techniques and broader applications are also discussed at the end of the review. [ABSTRACT FROM AUTHOR]

Most of the super hydrophobic paper surfaces prepared at present will change the original properties of the paper and can not be used for oil-water separation continuously. There is not yet much systematic research on super hydrophobic modification of paper-based materials. The use of polymers and inorganic fillers for synergistic modification is also relatively rare. In this paper, fluorine-containing epoxy polymer P(GMA- r -DFMA) and KH550 modified nano-SiO 2 were mixed to obtain an organic-inorganic hybrid super hydrophobic solution, which was chemically cross-linked to the surface of paper fibers to form a micro- and nano-thin coating to construct a super hydrophobic surface, but the original properties of the paper remain unchanged. The optimal parameters (polymer concentration, soaking time, drying time, drying temperature) for building super hydrophobic surface on paper were explored, and the optimal conditions are the polymer concentration of 7 mg/mL, soaking time of 5 h, drying time of 6 h, drying temperature of 100 °C. Under the optimum conditions, the water contact angle of the modified paper surface is 164 ± 2o and the water rolling angle is 5 ± 2o. The surface of the super hydrophobic modified paper contaminated with toner can be self-cleaned by water droplets. Compared with the unmodified paper, the whiteness, smoothness and glossiness of the surface of the super hydrophobic modified paper have not changed greatly. When the oils were n -hexane, n -octane and trichloromethane, the oil-water separation efficiency of the modified paper could reach 99.9 %, 99.9 % and 98 %, and the effects were stable. Super hydrophobic modified paper in water formed a large number of bubbles on its surface, resulting in silver mirror phenomenon. SEM results showed that the pore structure of the paper was not changed after modification. The surface of the original paper fiber is very smooth, but the surface of the super hydrophobic modified paper fiber has a large number of micro and nano protrusions. • Fluorine epoxy polymer and nano-SiO 2 were used to construct super hydrophobic paper, meanwhile original properties unchanged. • WCA is 164±2o and WRA is 5±2o. The super hydrophobic paper contaminated with toner can be self-cleaned by water droplets. • The whiteness, smoothness and glossiness of the super hydrophobic modified paper have not changed greatly. • The separation efficiency of the modified paper could above 98% when the oils were n -hexane, n -octane and trichloromethane. [ABSTRACT FROM AUTHOR]

[Display omitted] • Paper-based modification for a CA15-3 self-indicated test-strip. • Paper modified with a molecularly imprinted polymer (MIP) for CA15-3. • Paper with MIP concentrates (selectively) CA15-3 on its surface. • Coloured signal generated by reaction of TMB substrate with a peroxidase. • Peroxidase enzyme action upon substrate controls the colour intensity. The combination of molecularly-imprinted polymers (MIPs) on paper substrates for capturing a cancer antigen 15–3 (CA15-3) with the traditional coloured transduction scheme of enzyme-linked immunosorbent assay (ELISA) using 3,3′,5,5′-tetramethylbenzidine (TMB), horseradish peroxidase (HRP) and H 2 O 2 is presented here for the first time. Here, the paper surface was modified with a silane derivative containing an amine function that allows subsequent binding of 3-aminophenylboronic acid (3-APBA). The target protein, CA15-3, was then bound via the boronic groups of APBA. The empty space around CA15-3 was filled by polymerization of dopamine. Finally, the CA15-3 template was removed by breaking the imine function to create vacant sites for which CA15-3 has a high affinity. Binding of CA15-3 was detected by oxidation of TMB substrate by HRP in the presence of H 2 O 2. The results showed that the MIP was able to selectively recognize CA15-3 within 3–500 U mL−1, even in complex samples. Quantitative data were extracted by analysing the colour coordinates of images captured with a smartphone using ImageJ. This selective behaviour was confirmed by comparison with a control material (non– polymer, NIP). Overall, the described approach has advantages over conventional ELISA, namely low cost and high stability, which is due to the use of MIP as a trapping element acting as a selective pre-concentration point of CA15-3. To our knowledge, this is the first biomimetic ELISA (B-ELISA) on paper substrate used for macromolecules such as proteins. We believe that this approach has the potential to be applied to other protein disease biomarkers, making it a suitable tool for screening glycoproteins at the point-of-care. [ABSTRACT FROM AUTHOR]

Information on industrial paper obtained from special purpose heat-resistant and fire-resistant fibers by the method of fiber swelling is presented. Results of a study of the effect of fiber cutting length on the mechanical properties the paper are presented. Corresponding dependencies are established. [ABSTRACT FROM AUTHOR]

In continuation of previously reported results, the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene-1-ium acetate was also found to be a powerful non-derivatizing solvent for cellulosic waste such as paper and cardboard. The ionic liquid could dissolve all the present bio-polymers (cellulose, hemicellulose, and lignin) in high concentrations, resulting in solutions with visco-elastic properties that were suitable for dry-jet wet fiber spinning. The cellulosic raw materials were refined gradually to identify the influence of residual components on the spinnability of the respective solution. Polymer degradation and losses in the spinning process could be avoided nearly entirely. With the exception of virtually unrefined cardboard, all the samples showed excellent spinnability, resulting in fibers with high tensile strength. Prototype textiles were produced to validate the quality of the fibers and demonstrate the possibility of using residual lignin in cardboard as a natural dye. [ABSTRACT FROM AUTHOR]

It is well established that copper sulfide is formed due to reaction of sulfur with copper conductors in transformers and reactors. However, there is very little experimental evidence to demonstrate copper sulfide diffusion into bulk of paper. Diffusion experiments have been carried out on three samples of kraft paper having different thickness. Positron Annihilation Lifetime Spectroscopy has been used to investigate the possibilities of copper sulfide diffusion into bulk of paper. This study has demonstrated that copper sulfide can diffuse into the bulk of paper leading to either increase or decrease in free volume of paper. The reasons for changes in free volume of paper due to copper sulfide deposits are explained. The consequences of copper sulfide diffusion on PD, voltage-current characteristics under ac and volume resistivity are discussed. Electric field simulation has been used to explain the effects of Cu ions and copper sulfide formation on electric stress distribution across paper. [ABSTRACT FROM AUTHOR]

A flexible microporous polymer paper (MPP) is prepared with the polymer tubes obtained from the Sonogashira coupling reaction of 1,4-diiodotetrafluorobenzene and 1,3,5-triethynylbenzene. MPP has an interconnected network structure of polymer tubes and shows a hierarchical pore structure. Relatively large pores are formed among entangled polymer tubes, while micro- and mesopores are generated in the tube walls. MPP is foldable, mechanically stable, and stretchable. When the folding stress is removed, a wrinkle forms along the folded line, as observed in common papers composed of cellulose pulps. The mechanical stability of MPP results from electrostatic interactions between electron deficient tetrafluorobenzene units and electron rich triethynylbenzene units in the polymer. The tensile stress-tensile strain curve shows that MPP can elongate up to 15% strain. MPP is superhydrophobic, showing a water contact angle of 162° and can be used for the filtration of small molecules such as a dye and iodine. [ABSTRACT FROM AUTHOR]

Molecular chirality has traditionally been viewed as a binary property where a molecule is classified as either chiral or achiral, yet in recent decades, mathematical methods for quantifying chirality have been explored. Here, we use toy molecular systems to systematically compare the performance of two state-of-the-art chirality measures: (1) the Continuous Chirality Measure (CCM) and (2) the Chirality Characteristic (χ). We find that both methods exhibit qualitatively similar behavior when applied to simple molecular systems such as a four-site molecule or the polymer double-helix, but we show that the CCM may be more suitable for evaluating the chirality of arbitrary molecules or abstract structures such as normal vibrational modes. We discuss a range of considerations for applying these methods to molecular systems in general, and we provide links to user-friendly codes for both methods. We aim for this paper to serve as a concise resource for scientists attempting to familiarize themselves with these chirality measures or attempting to implement chirality measures in their own work. [ABSTRACT FROM AUTHOR]

Highlights • MIPs/CDs grafted paper-based sensor for selective and sensitive determination of 3-MCPD. • CDs were intercepted in the paper and MIPs was also directly formed on the paper-based sensor. • The composites exhibited high adsorption capacity and excellent selectivity. • This method could be applied for the detection of 3-MCPD in soy sauce samples. Abstract 3-Monochloropropane-1,2-diol (3-MCPD) is a common food processing contaminant and a simple, rapid, sensitive and low cost monitoring technology is needed due to its potential carcinogenic nature. Carbon dots directly intercepted on filter paper provide high fluorescence intensity and can be adapted for use as a sensor. We synthesized a carbon dot-filter paper in combination with a molecularly imprinted polymeric film to extract 3-MCPD from samples. This grafted paper-based sensor exhibited a high adsorption capacity (68.97 mg g−1), an excellent selectivity (imprinting factor = 4.5) and a low detection limit (0.6 ng mL−1). Recoveries ranged from 97.2% to 105.3% with relative standard deviations <5.6%. The results obtained using this method were linearly correlated to those of the classic GC–MS method (r = 0.998). Based on the Chinese National Standard, this study provides a novel and powerful platform for the simple, rapid, sensitive and on-site analysis of 3-MCPD in soy sauce. [ABSTRACT FROM AUTHOR]

This brief Technical Report summarizes the key points on the nomenclature of macromolecules and polymers. [ABSTRACT FROM AUTHOR]

Development of rapid, sensitive, and visual detection of nitroaromatic explosives is of great importance for homeland security and human safety. Herein, three novel fluorescent nanoporous polymers (FNPs), HPP-1–HPP-3, were first prepared by Heck reactions of octavinylsilsesquioxane with ethene derivatives containing bis-, tri-, or tetrakis- bromophenyl groups. Based on highly sensitive detection of explosives, including p -nitrotoluene (NT), 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), 4-nitrophenol (NP), 2,4-dinitrophenol (DNP) and picric acid (PA), and high selectivity for detecting TNT and PA, by HPP-2 dispersion in ethanol, a fluorescent paper sensor was developed by a new fabrication process, i.e. , vacuum filtrating of HPP-2 dispersion in ethanol, followed by washing and natural drying. The resultant paper sensor was found to be sensitive to explosives in the solution, solid and vapor phase with a rapid response time of < 10 s by visually observing the fluorescence quenching phenomenon. Moreover, this paper sensor is recyclable with desirable fluorescence resuming ratio, which is higher than 75% after 10 times recycle detection. This developed paper sensor is promisingly applied for rapid, on-site and visual sensing of explosive residuals. The remarkable fluorescence and reusability of this sensor could be expanded to other fluorescence detection of residuals. [ABSTRACT FROM AUTHOR]

Physics-guided machine learning (PGML) methods are emerging as valuable tools for modelling the constitutive relations of solids due to their ability to integrate both data and physical knowledge. While various PGML approaches have successfully modeled time-independent elasticity and plasticity, viscoelasticity remains less addressed due to its dependence on both time and loading paths. Moreover, many existing methods require large datasets from experiments or physics-based simulations to effectively predict constitutive relations, and they may struggle to model viscoelasticity accurately when experimental data are scarce. This paper aims to develop a physics-guided recurrent neural network (RNN) model to predict the viscoelastic behavior of solids at large deformations with limited experimental data. The proposed model, based on a combination of gated recurrent units (GRU) and feedforward neural networks (FNN), utilizes both time and stretch (or strain) sequences as inputs, allowing it to predict stress dependent on time and loading paths. Additionally, the paper introduces a physics-guided initialization approach for GRU–FNN parameters, using numerical stress–stretch data from the generalized Maxwell model for viscoelastic VHB polymers. This initialization is performed prior to training with experimental data, helping to overcome challenges associated with data scarcity. [ABSTRACT FROM AUTHOR]

Photochromic inks have shown disadvantages, such as poor durability and high cost. Self-healable hydrogels have shown photostability and durability. Herein, a viologen-based covalent polymer was printed onto a paper surface toward the development of a multi-stimuli responsive chromogenic sheet with thermochromic, photochromic, and vapochromic properties. Viologen polymer was created by polymerizing a dialdehyde-based viologen with a hydroxyl-bearing dihydrazide in an acidic aqueous medium. The viologen polymer was well immobilized as a colorimetric agent into a polyvinyl alcohol (PVA)/tricarboxy cellulose (TCC)-based self-healable hydrogel. The viologen/hydrogel nanocomposite films were applied onto a paper surface. The coloration measurements showed that when exposed to ultraviolet light, the orange layer printed on the paper surface switched to green. The photochromic film was used to develop anti-counterfeiting prints using the organic hydrogel composed of a PVA/TCC composite and a viologen polymer. Reversible photochromism with strong photostability was observed when the printed papers were exposed to UV irradiation. A detection limit was monitored in the range of 0.5–300 ppm for NH3(aq). The exposure to heat (70 °C) was found to reversibly initiate a colorimetric change. [ABSTRACT FROM AUTHOR]

Pyrolysis characteristics of Tetra Pak, a paperboard-polyethylene-aluminium foil, were investigated in this study with a focus on the synergistic effect between its individual components. Scanning electron microscopy analysis indicated that molten LDPE coating on cellulose surface led to suppression on mass and heat transfer and the increased activation energy of pyrolysis reaction. Samples of individual components and simulated Tetra Pak packaging were pyrolyzed in a thermogravimetric analyzer at various heating rates. Synergistic effect between cellulose and LDPE on E a and the formation of characteristic products are investigated: Kinetic analysis showed that the cellulose decomposition peak in the simulated mixture exhibited a higher E a than that of pure cellulose at each conversion rate. For LDPE, the free radicals formed from cellulose pyrolysis enhanced the degradation of plastic polymers, resulting that E a of its decomposition peak in the mixture being lower in comparison to pure LDPE, with a discrepancy of around 16–27 kJ·mol−1. The formation of characteristic products including levoglucosan, furfural, 5-hydroxymethylfurfural, and alkanes from pyrolysis of cellulose and LDPE mixture with different mass ratios was further investigated in a micro-pyrolyzer. The results suggested that synergistic effects and physical barrier existed during fast pyrolysis between cellulose and LDPE. The extent of the synergy effect depended on the proportion of cellulose and LDPE in the mixture. • Synergistic effect was investigated during pyrolysis of Tetra Pak. • Molten LDPE coating on cellulose increases E a of cellulose pyrolysis. • The extent of synergy effect depends on the proportion of cellulose and LDPE. [ABSTRACT FROM AUTHOR]

In this work, gold nanoparticles (AuNPs) and a molecular imprinted polymer (MIP) were modified on an exfoliated graphite paper (EGP) surface to fabricate a novel electrochemical sensor for tertiary butylhydroquinone (TBHQ) selective detection. The scanning electron microscope image showed that the sensor possessed a three-dimensional (3D) structure with AuNPs and MIP uniform coverage. The high surface area of the 3D sensor and the thin film of MIP made the imprinted cavities situate at the surface or approximately to the surface of the sensor to speed up the mass transfer. Due to the good conduction of AuNPs and EGP, as well as large surface area of EGP, the sensor showed a high sensitivity for TBHQ detection. The linear range were 8.0 × 10 −8 − 1.0 × 10 −4 mol/L and 7.0 × 10 −8 mol/L, in a range of 8.0 × 10 −8 − 1.0 × 10 −6 mol/L, 1.0 × 10 −6 –1.0 × 10 −4 mol/L. And the limit of detection (LOD) was 1.2 × 10 −8 mol/L (S/N = 3). Owing to the specific adsorption of MIP, the sensors can selectively recognize TBHQ from its structural similar compounds. The sensor has been applied to analyze TBHQ in real samples with satisfactory results. The simple, low cost, and effective sensor reported here has promising perspectives for other compounds rapid recognition and sensitive detection. [ABSTRACT FROM AUTHOR]

Security inks based on photoluminescent materials are mostly investigated for security applications, such as information encryption and decryption, anti‐counterfeiting, and data storage. Although they are invisible to the naked eye under ambient light, they can be detected under ultraviolet or near‐infrared light. Herein, a new kind of secret paper made from network‐structured ultralong hydroxyapatite nanowires and cellulose fibers has been developed. White vinegar, a common cooking ingredient, is used as an invisible security ink. Covert information on the secret paper written with white vinegar is totally invisible under natural light, but it can be decrypted and clearly read after exposure to fire; the response time to fire is short (<10 s). The ways of writing on the secret paper are diverse by using various pens loaded with white vinegar. [ABSTRACT FROM AUTHOR]

There is a continuing demand for bio-sustainable and readily recyclable polymers for hot food packaging and hot beverage containers. An important candidate for these applications is poly(lactic acid), PLA, which possesses insufficient heat deflection temperature (HDT) performance, short of being fully crystallized. In order to address this issue, correlations were established for the observed enhancement in HDT with PLA resin after annealing with both thermal properties and the crystallinity of PLA (Ingeo™ 4032D) and extrusion melt blends thereof. The kinetic parameters of crystallization (reaction order, n and rate constant, k (s)) were obtained after fitting the Avrami equation. The reaction order for all of the systems had an n of approximately 3. Models derived from the Avrami equation with n ~ 3 are consistent with systems that undergo heterogeneous nucleation and subsequent spherulitic crystal growth. The addition of paper and talc did not change the model but did change the rate of crystallization. An increased quantity of cellulosic filler led to an increased rate of crystallization. The smaller particle sized fillers offered the greatest improvement in the rate of crystallization. However, the smaller-sized inorganic fillers did not appear to further improve HDT above that of the annealed blends of PLA/paper. The melting temperature for the PLA and all of the blends thereof formed containing paper from different sources of talc had identical melting temperatures ( T ). The variations in the HDTs of the composites were not found to be mirrored in the T . Annealing typically raised the crystallinity from approximately 10-15 to 30-40%. In situ determinations of enhanced moduli via annealing were performed using solid torsion bar dynamic mechanical spectroscopy, the results of which support the findings obtained via DSC. The annealed PLA/paper blends were found to be superior overall to the PLA/talc blends and are, importantly, sustainable. [ABSTRACT FROM AUTHOR]

This paper proposes a layer-by-layer acoustic travel time approximation method based on ray theory for total focusing method (TFM) imaging in carbon fiber reinforced polymer (CFRP) laminates. The method considers the anisotropy in every monolayer and heterogeneity of CFRP, which approximates the path of propagation as straight in the whole material. The application of this method to TFM imaging is called TravelTimeAppro-TFM. In comparison to isotropic-TFM and Dijkstra-TFM, the experimental results indicated that TravelTimeAppro-TFM outperforms isotropic-TFM in terms of imaging amplitude gain with a maximum gain of 4.67 dB. On the other hand, this approach reduces the computational work compared to Dijkstra-TFM. The proposed method demonstrates significant improvements in both focusing performance and the speed of calculation. This paper also investigates the effective angular range of the layer-by-layer acoustic travel time approximation method through experimental and finite element simulation analysis. [ABSTRACT FROM AUTHOR]

Conductive paper was prepared via in situ chemical oxidative polymerization of 3,4-ethylenedioxythiophene (EDOT) in pulp suspension by using iron(III) p-toluenesulfonate (Fe(OTs)3) as both an oxidant and a dopant source. The deposition of poly(3,4-ethylenedioxythiophene) (PEDOT) on the pulp fiber surface was verified and characterized by ATR-FTIR and SEM analyses. The factors affecting the conductivity of the PEDOT-coated paper were investigated, and the preparation conditions of the conductive paper with a low resistivity and excellent environmental stability was obtained. The optimum reaction temperature and time were 60 °C and 4 h, respectively. The molar ratio of EDOT to Fe(OTs)3 of 1:1 was optimal when considering both cost and performance factors. The conductivity of the PEDOT-coated paper could be controlled by adjusting EDOT concentration. The threshold concentration of EDOT was about 3 g⋅L-1, and a volume resistivity as low as 5.9x10³ Ω⋅cm could be achieved, which reached the conductivity range of an electrical conductor. The environmental stability of the PEDOT-coated conductive paper was very good due to the much higher oxidation potential of PEDOT. [ABSTRACT FROM AUTHOR]

This paper presents a method to improve the mechanical properties and breakdown strength of aramid insulation paper. By combining molecular dynamics simulation and experimental analysis, the mechanisms for these improvements were studied. By investigating the relationships between the micro parameters of the models and the nanoparticle content, the optimum nanoparticle content was established to be 1 wt.%. Subsequently, an insulation paper with the same content of nanoparticles as the simulation experiment was prepared in the laboratory and its tensile strength, breaking elongation, power frequency breakdown strength, and other characteristic parameters were tested. The results showed that the properties of the insulation paper modified by nano-SiO2 had greatly improved. Finally, the interface interaction and microscopic mechanism by which the nano-SiO2 improved the properties of the insulation paper were analyzed. On the one hand, a strong interfacial interaction formed between the nanoparticles and the aramid fiber, which allowed them to combine well; on the other hand, the addition of nanoparticles effectively reduced the free volume of the aramid fiber. Therefore, the mechanical properties, thermal stability, and electrical properties of the aramid insulation paper were improved. [ABSTRACT FROM AUTHOR]

Porous carbon is a pivotal material for electrochemical applications. The manufacture of porous carbon has relied on chemical treatments (etching or template) that require processing in all areas of the carbon/carbon precursor. We present a unique approach to preparing porous carbon nanospheres by inhibiting the pyrolytic condensation of polymers. Specifically, the porous carbon nanospheres are obtained by coating a thin film of ZnO on polystyrene spheres. The porosity of the porous carbon nanospheres is controlled by the thickness of the ZnO shell, achieving a BET-specific area of 1,124 m²/g with a specific volume of 1.09 cm³/g. We confirm that under the support force by the ZnO shell, a hierarchical pore structure in which small mesopores are connected by large mesopores is formed and that the pore-associated sp³ defects are enriched. These features allow full utilization of the surface area of the carbon pores. The electrochemical capacitive performance of porous carbon nanospheres was evaluated, achieving a high capacitance of 389 F/g at 1 A/g, capacitance retention of 71% at a 20-fold increase in current density, and stability up to 30,000 cycles. In particular, we achieve a specific area-normalized capacitance of 34.6 µF/cm², which overcomes the limitations of conventional carbon materials. [ABSTRACT FROM AUTHOR]

Abstract Use of paper-based devices for affordable diagnostics is gaining interest due to unique advantages such as affordability, portability, easy disposability and inherent capillarity. As capillary transportation is an integral component of paper-based devices, low sample volume with faster measurement becomes an additional advantage. We have developed a simple, paper-based microfluidic device suitable for measuring the viscosity of Newtonian fluids as well as a few non-Newtonian fluids with sample volume as little as 12–20 μL. The results could be obtained much faster than the conventional methods. A comparative analysis of the results obtained with our paper-based viscometer and with that of the conventional Ostwald viscometer shows a correlation coefficient greater than 0.99. Apart from viscosity measurement, the paper-based devices were tested for protein denaturation and polymer molecular weight determination. Our results show that the paper-based viscometer could be a potential alternative for the conventional viscometers in the viscosity range from 0.9 cP up till ∼40 cP, with added benefits in terms of time, cost and low sample volume requirement. Graphical abstract Image 1 Highlights • Paper-based viscometer (PBV) with correlation coefficient >0.999 w.r.t. Ostwald's. • First PBV to measure viscosity of Newtonian and non-Newtonian fluids. • First report of use of PVB for protein-stability and molecular weight determination. [ABSTRACT FROM AUTHOR]

Polymers and surfactants are used in many technological and industrial applications such as the manufacture of functional materials and coatings, personal care and pharmaceutical products, food science, paints, anti-icing fluids, tertiary oil recovery and the paper industry. Polymer–surfactant mixtures are particularly important in shampoos and conditioners. However, as in almost every other industry over the past five or more decades, the performance of hair care formulations has been significantly improved by the use of petrochemical-derived ingredients. As a result, cosmetic formulations, and hair care formulations in particular, have been based primarily on polymers and surfactants that are neither renewable, nor derived from environmentally friendly processes, nor have a positive environmental impact. This contrasts with the extensive use of natural and renewable products, mainly plant extracts, in cosmetics in ancient times. Therefore, the substitution of currently used ingredients with others of natural origin has been a top priority for the cosmetic industry over the last two decades, and in order to achieve greater consumer acceptance, it is crucial to maintain and, where possible, improve the technical performance of such products. This paper describes the complexities and challenges of developing greener shampoo and conditioner ingredients and formulations to meet current and future needs, and outlines a methodological approach based on model hair surfaces and a selection of appropriate experimental and numerical techniques to achieve our goals. Some encouraging technical routes using biosurfactants, biopolymers and bio-based polymers are presented, along with the significant opportunity to obtain a wide range of green ingredients through molecular design and well-controlled biotechnological processes. Similar concerns apply to other cosmetic products such as waxes, fragrances, bleaching agents, etc. [ABSTRACT FROM AUTHOR]

The demand for high-performance bio-based materials towards achieving more sustainable manufacturing and circular economy models is growing significantly. Kraft lignin (KL) is an abundant and highly functional aromatic/phenolic biopolymer, being the main side product of the pulp and paper industry, as well as of the more recent 2nd generation biorefineries. In this study, KL was incorporated into a glassy epoxy system based on the diglycidyl ether of bisphenol A (DGEBA) and an amine curing agent (Jeffamine D-230), being utilized as partial replacement of the curing agent and the DGEBA prepolymer or as a reactive additive. A D-230 replacement by pristine (unmodified) KL of up to 14 wt.% was achieved while KL–epoxy composites with up to 30 wt.% KL exhibited similar thermo-mechanical properties and substantially enhanced antioxidant properties compared to the neat epoxy polymer. Additionally, the effect of the KL particle size was investigated. Ball-milled kraft lignin (BMKL, 10 μm) and nano-lignin (NLH, 220 nm) were, respectively, obtained after ball milling and ultrasonication and were studied as additives in the same epoxy system. Significantly improved dispersion and thermo-mechanical properties were obtained, mainly with nano-lignin, which exhibited fully transparent lignin–epoxy composites with higher tensile strength, storage modulus and glass transition temperature, even at 30 wt.% loadings. Lastly, KL lignin was glycidylized (GKL) and utilized as a bio-based epoxy prepolymer, achieving up to 38 wt.% replacement of fossil-based DGEBA. The GKL composites exhibited improved thermo-mechanical properties and transparency. All lignins were extensively characterized using NMR, TGA, GPC, and DLS techniques to correlate and justify the epoxy polymer characterization results. [ABSTRACT FROM AUTHOR]

Recent experiments by Brückner et al. [Science 380, 1357 (2023)] have observed an anomalous chain length dependence of the time of near approach of widely separated pairs of genomic elements on transcriptionally active chromosomal DNA. In this paper, I suggest that the anomaly may have its roots in internal friction between neighboring segments on the DNA backbone. The basis for this proposal is a model of chain dynamics formulated in terms of a continuum scaled Brownian walk (sBw) of polymerization index N. The sBw is an extension of the simple Brownian walk model widely used in path integral calculations of polymer properties, differing from it in containing an additional parameter H (the Hurst index) that can be tuned to produce varying degrees of correlation between adjacent monomers. A calculation using the sBw of the mean time τc for chain closure predicts—under the Wilemski–Fixman approximation for diffusion-controlled reactions—that at early times, τc varies as the 2/3 power of N, in close agreement with the findings of the Brückner et al. study. Other scaling relations of that study, including those related to the probability of loop formation and the mean square displacements of terminal monomers, are also satisfactorily accounted for by the model. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract In this work, we constructed a sensing system on Janus paper with hydrophilic side and hydrophobic side via depositing polymer precursor onto one side of qualitative filter paper. Water in humid environment (including liquid water, condensed moisture airflow and gaseous humid atmosphere) will be captured and gathered in the hydrophilic region of Janus paper due to the asymmetric hydrophobicity and hygroscopicity, which can induce the novel directional deformation. Additionally, MWCNTs (multiwalled carbon nanotubes) were loaded onto hydrophobic region beforehand to construct conductive network. The resistance of the conductive network changes synergistically as the Janus paper deforms in humid environment. Thus, the novel Janus paper realized the induction of environment humid factors, and conversion from the deformation signals to the desirable electric signals. The Janus paper also shows excellent stability in cycle use. [ABSTRACT FROM AUTHOR]

Owing to the multiple potential health risks caused by exposure to BPA and the strengthened regulation of BPA-containing thermal papers, much concern has been raised recently regarding a BPA-type color developer in thermal papers. However, few efforts have so far been focused on the development of safer alternative materials to BPA. In this study, we examined the use of polymeric materials as a safer replacement for BPA in thermal papers. For this objective, a series of phenolic polymers, phenol-formaldehyde novolac and resole (PF-N and PF-R) and BPA-formaldehyde novolac and resole (BPAF-N and BPAF-R), were prepared. Among these polymers, a BPAF-N-type polymer was determined to be the most appropriate candidate for a developer material in thermal papers. Through printing tests of the prepared thermal papers, it was found that BPAF-N_8 polymer has a high static sensitivity and dark contrast of thermal papers similar to those of BPA, whereas the BPAF-N_16 and BPAF-N_30 polymers have lower static sensitivities than BPFA-N_8 and BPA. [ABSTRACT FROM AUTHOR]