Cyclopentasiloxane (D5) as a Non-Polar Masking Agent for Water-Sensitive Substrates During Polar Solvent Treatment

D5 (decamethylcyclopentasiloxane), a non-polar solvent that evaporates slowly, was tested for its suitability as a temporary masking agent for water-sensitive media on paper objects undergoing aqueous treatment. Three different treatment-related settings were tested on five different paper types, some prepared with water-soluble inks. In 10-min water immersion treatments, D5 proved largely ineffectual in protecting the water-soluble inks. In conjunction with melt-applications of cyclododecane, the addition of D5 enhanced its barrier function only in one case. To test the ability of D5 to prevent tideline formation, the test samples received applications of water, acetone, and a water-ethanol-mixture, creating an interface with freshly D5-impregnated areas. The papers were evaluated visually (VIS, UVA), some after artificial aging. D5 diminished the formation of visible tidelines in the two internally sized papers with low water absorbency in contact with acetone and the ethanol-water mixture, but did not prevent tidelines in contact with water. It also did not protect water-absorbent paper. The results indicate that D5, which is miscible with ethanol and acetone, may disperse tidelines caused by these solvents, but it proved largely insufficient for protecting media during water immersion.

Physico-chemical properties of gathot (fermented cassava) flour applied on edible film

The objective of this research is to examine the physicochemical properties of gathot and its potential as an edible film. The materials used included dried gathot, carrageenan, and glycerol with 4 levels of treatment and 5 repetitions. The treatment was in the form of variation of gathot flour’s concentration (0.00; 0.75; 1.00; 1.25 %). The test was conducted on gathot flour, covering scavenging ability, bulk density, water absorbency, color brightness, proximate analysis and crude fiber with descriptive analysis. Gathot flour-derived edible film’s characteristics were tested for tensile strength and water vapor transmission rate (WVTR) to examine whether gathot flour-derived edible film was able to compete with commercial bioplastics through quantitative statistical analysis and Completely Randomized Design (RAL) and processing with SPSS 23.0. The results of physicochemical test on gathot flour were scavenging ability 49.37%; bulk density 0.57 g/mL; water absorbency 2.37 g/g; color brightness 17.42; water content 9.32%; protein content 4.76%; fat content 0.13%; ash content 0.09%; carbohydrate 85.70%; and crude fiber 3.54%. The average results of edible film’s characteristics test with a variation of gathot flour’s concentration were tensile strength 1.41-3.00 N/mm2 and water vapor transmission rate (WVTR) 5.42-6.99%. From the perspective of physicochemical properties, it is concluded that gathot flour is almost equal to wheat flour and tapioca flour. In addition, gathot flour-derived edible film at up to concentration level 1.25% has met the criteria for the edible film with moderate properties and complied with the standard bioplastic packaging.

Innovative Banana Fiber Nonwoven Reinforced Polymer Composites: Pre- and Post-Treatment Effects on Physical and Mechanical Properties

Four types of nonwovens were prepared from different sections of the banana tree e.g., outer bark (OB), middle bark (MB), inner bark (IB) and midrib of leaf (MR) by wet laid web formation. They were reinforced with two different types of matrices e.g., epoxy and polyester, to make eight variants of composites. Treatments including alkali on raw fibers, water repellent on nonwovens and gamma radiation on composites were applied in order to investigate their effects on properties of the composites such as water absorbency, tensile strength (TS), flexural strength (FS) and elongation at break (Eb%). Variations in the morphological structure and chemical composition of both raw banana fibers and fibers reinforced by the treatments were analyzed by Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM). OB composites exhibited higher water absorbency, TS and FS and lower Eb% compared to other types of composites. Epoxy composites were found to have 16% lower water absorbency, 41.2% higher TS and 39.1% higher FS than polyester composites on an average. Water absorbency of the composites was reduced 32% by the alkali treatment and a further 63% by water repellent treatment. TS and FS of the composites were on average improved 71% and 87% by alkali treatment and a further 30% and 35% by gamma radiation respectively.

Water-Preserving and Salt-Resistant Slow-Release Fertilizers of Polyacrylic Acid-Potassium Humate Coated Ammonium Dihydrogen Phosphate

Polyacrylic acid (PAA) has high water absorbency but poor salt resistance. Humic acid (HA) extracted from lignite was introduced into the cross-linked copolymer systems of AA to improve the water absorbency and salt-tolerance. A polyacrylic acid-potassium humate (PAA-KHA) coated ammonium dihydrogen phosphate (ADP) fertilizer with water-preserving, salt-resistant and slow-release properties was prepared. The main properties of HA extracted from lignite oxidized by H2O2 were studied. Furthermore, the synthesis process, water absorbency of PAA-KHA in deionized water and in NaCl solution, morphologies of PAA-KHA, and the slow-release performance of the fertilizer (ADP@PAA-KHA) were investigated. The results showed PAA-KHA had a layered interpenetrating network, which can provide sufficient storage space for water and nutrients. The salty water absorbency of PAA-KHA increased by about 3 times compared to PAA. Both the PO43− and NH4+ cumulative release of ADP@PAA-KHA with a coating rate of 10% in deionized water, were less than 20% within 24 h, and were 55.71% and 28.04% after the 15th day, respectively. The weight change of ADP@PAA-KHA before and after absorbing water was about 53 times in deionized water and about 4 times in 1 wt% of NaCl salty water. The results show that ADP@PAA-KHA has excellent properties of water retention, salt resistance and slow-release. This will efficiently improve the utilization of fertilizer and reduce the irrigation water consumption at the same time.

Formalin-casein enhances water absorbency of calcium alginate beads and activity of encapsulated Metarhizium brunneum and Saccharomyces cerevisiae

The control of root-feeding wireworms has become more challenging as synthetic soil insecticides have been progressively phased out due to environmental risk concerns. Innovative microbial control alternatives such as the so-called attract-and-kill strategy depend on the rapid and successful development of dried encapsulated microorganisms, which is initiated by rehydration. Casein is a functional additive that is already used in food or pharmaceutical industry due to its water binding capacity. Cross-linked forms such as formalin-casein (FC), exhibit altered network structures. To determine whether FC influences the rehydration of alginate beads in order to increase the efficacy of an attract-and-kill formulation for wireworm pest control, we incorporated either casein or FC in different alginate/starch formulations. We investigated the porous properties of alginate/starch beads and subsequently evaluated the activities of the encapsulated entomopathogenic fungus Metarhizium brunneum and the CO2 producing yeast Saccharomyces cerevisiae. Adding caseins altered the porous structure of beads. FC decreased the bead density from (1.0197 ± 0.0008) g/mL to (1.0144 ± 0.0008) g/mL and the pore diameter by 31%. In contrast to casein, FC enhanced the water absorbency of alginate/starch beads by 40%. Furthermore, incorporating FC quadrupled the spore density on beads containing M. brunneum and S. cerevisiae, and simultaneous venting increased the spore density even by a factor of 18. Moreover, FC increased the total CO2 produced by M. brunneum and S. cerevisiae by 29%. Thus, our findings suggest that rehydration is enhanced by larger capillaries, resulting in an increased water absorption capacity. Our data further suggest that gas exchange is improved by FC. Therefore, our results indicate that FC enhances the fungal activity of both fungi M. brunneum and S. cerevisiae, presumably leading to an enhanced attract-and-kill efficacy for pest control. Graphic abstract

Innovated Banana Fiber Nonwoven Reinforced Polymer Composites: Effects of Pre- and Post-treatments on Physical and Mechanical Properties

Four types of nonwovens were prepared from different sections of the banana tree e.g., outer bark (OB), middle bark (MB), inner bark (IB) and midrib of leaf (MR) by wet laid web formation. They were reinforced on two different types of matrices e.g., epoxy (E) and polyester (P) to make eight variants of composites. Different concentration (5–15%) of NaOH and water repellent (WR); and different doses (100-500krd) of gamma radiation were applied in different stages of process. The properties like water absorbency, tensile strength (TS), flexural strength (FS) and elongation at break (Eb%) were investigated. OB composites were exhibited higher water absorbency, TS and FS but lower Eb% than other types of composites. Epoxy composites were found to have 16% lower water absorbency, 41.2% higher TS and 39.1% higher FS than polyester composites on an average. Alkali treatment reduced the water absorbency by 32%; improved the TS by 71%; improved the FS by 87% on an average at 15% NaOH. Water repellent treatment (on alkali treated composites) decreased the absorbency by 63% at 10% WR but increased 6.3% at 15% WR. Gamma radiation improved the TS of 30% and FS of 35% on an average at a dose of 100krd for IB and 200krd for other composites. Further increment of dose reduced both the FS and TS.

An Innovative Computational Strategy to Optimize Different Furnish Compositions of Tissue Materials Using Micro/Nanofibrillated Cellulose and Biopolymer as Additives

The furnish management of tissue materials is fundamental to obtain maximum quality products with a minimum cost. The key fiber properties and fiber modification process steps have a significant influence on the structural and functional properties of tissue paper. In this work, two types of additives, a commercial biopolymer additive (CBA) that replaces the traditional cationic starch and micro/nanofibrillated cellulose (CMF), were investigated. Different formulations were prepared containing eucalyptus fibers and softwood fibers treated mechanically and enzymatically and both pulps with these two additives incorporated independently and simultaneously with drainage in the tissue process range. The use of these additives to reduce the percentage of softwood fibers on tissue furnish formulations was investigated. The results indicated that a maximum of tensile strength was obtained with a combination of both additives at the expense of softness and water absorbency. With a reduction of softwood fibers, the incorporation of additives increased the tensile strength and water absorbency with a slight decrease in HF softness compared with a typical industrial furnish. Additionally, a tissue computational simulator was also used to predict the influence of these additives on the final end-use properties. Both additives proved to be a suitable alternative to reduce softwood fibers in the production of tissue products, enhancing softness, strength and absorption properties.

Novel Superabsorbent Polymer Composites Based on α-Cellulose and Modified-Zeolite: Synthesis, Characterization, Water Absorbency and Water Retention Capacity

Most superabsorbent polymers (SAP) are fully based on synthetic polymer (from petroleum resources) but costly, nondegradable, and environment-unfriendly. To overcome these disadvantages, biodegradable and renewable natural materials are suggested to be added into SAP. In this article, a new kind of SAP composites was synthesized by using AA, AM, α-cellulose, and modified-zeolite (MZE) as raw materials. The prepared novel SAP composite was analyzed by FTIR, XRD, SEM and TGA. Then, its water absorbency and water retention capacity were evaluated. The AA and AM were successfully grafted on α-cellulose chains and the introduction of MZE as an inorganic filler which is uniformly dispersed in the SAP composite matrix, both resulting in more undulant and coarser surface with abundant hydrophilic groups for novel SAP composites. By contrast with poly(AA-co-AM), the water absorbency of prepared novel SAP composites is increased by 93.88% in distilled water and 89.58% in 0.9 wt.% NaCl solution, respectively. Meanwhile, the retained water time of these SAP composites is 11.2 hs evaluated at 50 °C, increasing the water retention capacity by 71.79%. Moreover, both Tonset and Tpeak of prepared novel SAP composites are slightly increased compared with α-cellulose-poly(AA-co-AM), showing the introduction of MZE can slightly improve the thermal stability of novel SAP composites. The excellent water absorbency and retention capacity of novel SAP composites show it can be used as a water-keeping material for agricultural and horticulture applications.