Synthetic fibers, mainly polyethylene terephthalate (PET), polyamide (PA), polyacrylonitrile (PAN) and polypropylene (PP), are the most widely used polymers in the textile industry. These fibers surpass the production of natural fibers with a market share of 54.4%. The advantages of these fibers are their high modulus and strength, stiffness, stretch or elasticity, wrinkle and abrasion resistances, relatively low cost, convenient processing, tailorable performance and easy recycling. The downside to synthetic fibers use are reduced wearing comfort, build-up of electrostatic charge, the tendency to pill, difficulties in finishing, poor soil release properties and low dyeability. These disadvantages are largely associated with their hydrophobic nature. To render their surfaces hydrophilic, various physical, chemical and bulk modification methods are employed to mimic the advantageous properties of their natural counterparts. This review is focused on the application of recent methods for the modification of synthetic textiles using physical methods (corona discharge, plasma, laser, electron beam and neutron irradiations), chemical methods (ozone-gas treatment, supercritical carbon dioxide technique, vapor deposition, surface grafting, enzymatic modification, sol-gel technique, layer-by-layer deposition of nano-materials, micro-encapsulation method and treatment with different reagents) and bulk modification methods by blending polymers with different compounds in extrusion to absorb different colorants. Nowadays, the bulk and surface functionalization of synthetic fibers for various applications is considered as one of the best methods for modern textile finishing processes (Tomasino, 1992). This last stage of textile processing has employed new routes to demonstrate the great potential of nano-science and technology for this industry (Lewin, 2007). Combination of physical technologies and nano-science enhances the durability of textile materials against washing, ultraviolet radiation, friction, abrasion, tension and fading (Kirk–Othmer, 1998). European methods for application of new functional finishing materials must meet high ethical demands for environmental-friendly processing (Fourne, 1999). For this purpose the process of textile finishing is optimized by different researchers in new findings (Elices & Llorca, 2002). Application of inorganic and organic nano-particles have enhanced synthetic fibers attributes, such as softness, durability, breathability, water repellency, fire retardancy and antimicrobial properties (Franz, 2003; McIntyre, 2005; Xanthos, 2005). This review article gives an application overview of various physical and chemical methods of inorganic and organic structured material as potential modifying agents of textiles with emphasis on dyeability enhancements. The composition of synthetic fibers includes polypropylene (PP), polyethylene terephthalate (PET), polyamides (PA) or polyacrylonitrile (PAN). Synthetic fibers already hold a 54% market share in the fiber market. Of this market share, PET alone accounts for almost 50% of all fiber materials in 2008 (Gubitz & Cavaco-Paulo, 2008). Polypropylene, a major component for the nonwovens market accounts for 10% of the market share of both natural and synthetic fibers worldwide (INDA, 2008 and Aizenshtein, 2008). It is apparent that synthetic polymers have unique properties, such as high uniformity, mechanical strength and resistance to chemicals or abrasion. However, high hydrophobicity, the build-up of static charges, poor breathability, and resistant to finishing are undesirable properties of synthetic materials (Gubitz & Cavaco-Paulo, 2008). Synthetic textile fibers typically undergo a variety of pre-treatments before dyeing and printing is feasible. Compared to their cotton counterparts, fabrics made from synthetic fibers undergo mild scouring before dyeing. Nonetheless, these treatments still create undesirable process conditions wh
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The invention relates to the use of modified starch obtainable by treating amylose containing starch in aqueous medium with an enzyme from the group of the α-1,4-α-1,4-glucosyl transferases (EC 2.4.1.25) or an enzyme the activity of which corresponds to that of enzymes from the group just mentioned, as an agent for forming a thermoreversible gel. The invention also relates to products in the form of a thermoreversible gel having as gel-forming substance a modified starch as defined. The invention further relates to the use of a modified starch as defined in the form of an aqueous solution.
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Active antifungal packaging is a technological solution for reducing the postharvest losses of fruits and vegetables associated with phytopathogens. Anthracnose (Colletotrichum gloeosporioides) is the principal fungus that causes post-harvest avocado fruit decay. In this study, antifungal sachets filled with oregano oil-starch capsules were prepared, and their active effects were demonstrated on Hass avocado fruits. Oregano oil (31 % of carvacrol) was encapsulated with corn starch by spray drying. Tyvek sachets (4 × 4 cm) filled with 80 (T1) and 160 mg (T2) of oregano oil-starch capsules (99.35 ± 1.86 mg g − 1) were fabricated. The antifungal effects of the sachets were tested in vitro and in vivo using a humidity chamber (90–95 % relative humidity (RH)) on fruits inoculated with anthracnose. The results showed that T1 and T2 inhibited 75.21 ± 2.81 and 100 % in vitro growth of anthracnose at 25 °C for 12 days. Furthermore, Hass avocado fruits stored in a humidity chamber at 25 °C for 6 days showed that only T2 significantly (p < 0.05) reduced the area of lesion produced by artificial inoculation of Hass avocado fruits with anthracnose. On average, the lesion area in the Hass avocado fruits treated with T2 was 13.94 % smaller than that in the control fruit.
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Verduurzaming van de chemische en landbouwsector is essentieel om de klimaat- en circulaire doelstellingen te halen. Eén van de mogelijkheden om de chemische sector te vergroenen is om hernieuwbare grondstoffen als feedstock voor productie te gebruiken. Met name laagwaardige reststromen uit de agrarische sector komen hiervoor in aanmerking. In dit project wordt beoogd om koeienurine, die gescheiden is opgevangen van de ontlasting, te valoriseren richting hoogwaardige componenten voor (fijn)chemie en meststoffen. De focus zal in eerste instantie liggen op de isolatie van hippuurzuur en hieruit te synthetiseren benzoëzuur en glycine en de verwaarding van de resterende fractie richting natuurlijke meststoffen (kalium en ureum) voor de akker/tuinbouw. Het verkregen groene benzoëzuur is een goed alternatief voor het huidige uit de petrochemie gesynthetiseerde zuur en kan bijvoorbeeld als natuurlijk conserveringsmiddel in mengvoeders worden gebruikt. In een latere fase zullen ook overige waardevolle componenten (allantoine, creatinine, creatine, etc.) uit urine van koeien worden geïsoleerd en gevaloriseerd. Een succesvol project draagt bij aan het verbeteren van de business case van veetelers en maakt de scheiding van urine en ontlasting in de stallen aantrekkelijker. Additionele revenuen die uit de bioraffinage van urine worden verkregen kunnen gebruikt worden om de gedane investeringen in het “koeientoilet” terug te verdienen. De scheiding van urine en ontlasting levert een significante reductie in ammoniak-emissies op en draagt hiermee bij aan het oplossen van het “stikstofprobleem”. Reductie van CO2 wordt o.a. bewerkstelligd door verminderd gebruik van kunstmest en vervanging van uit de petrochemie afkomstige chemicaliën (benzoëzuur) door synthese uit natuurlijke (hernieuwbare) grondstoffen.
Aiming for a more sustainable future, biobased materials with improved performance are required. For biobased vinyl polymers, enhancing performance can be achieved by nanostructuring the material, i.e. through the use of well-defined (multi-)block, gradient, graft, comb, etc., copolymer made by controlled radical polymerization (CRP). Dispoltec has developed a new generation of alkoxyamines, which suppress termination and display enhanced end group stability compared to state-of-art CRP. Hence, these alkoxyamines are particularly suited to provide access to such biobased nanostructured materials. In order to produce alkoxyamines in a more environmentally benign and efficient manner, a photo-chemical step is beneficial for the final stage in their synthesis. Photo-flow chemistry as a process intensification technology is proposed, as flow chemistry inherently leads to more efficient reactions. In particular, photo-flow offers the benefit of significantly enhancing reactant concentrations and reducing batch times due to highly improved illumination. The aim of this project is to demonstrate at lab scale the feasibility of producing the new generation of alkoxy-amines via a photo-flow process under industrially relevant conditions regarding concentration, duration and efficiency. To this end, Zuyd University of Applied Sciences (Zuyd), CHemelot Innovation and Learning Labs (CHILL) and Dispoltec BV want to enter into a collaboration by combining the expertise of Dispoltec on alkoxyamines for CRP with those of Zuyd and CHILL on microreactor technology and flow chemistry. Improved access to these alkoxyamines is industrially relevant for initiator manufacturers, as well as producers of biobased vinyl polymers and end-users aiming to enhance performance through nanostructuring biobased materials. In addition, access in this manner is a clear demonstration for the high industrial potential of photo-flow chemistry as sustainable manufacturing tool. Further to that, students and professionals working together at CHILL will be trained in this emerging, industrially relevant and sustainable processing tool.
In the context of sustainability, the use of biocatalysis in organic synthesis is increasingly observed as an essential tool towards a modern and ‘green’ chemical industry. However, the lack of a diverse set of commercially available enzymes with a broad selectivity toward industrially-relevant substrates keeps hampering the widespread implementation of biocatalysis. Aminoverse B.V. aims to contribute to this challenge by developing enzymatic screening kits and identifying novel enzyme families with significant potential for biocatalysis. One of the most important, yet notoriously challenging reaction in organic synthesis is site-selective functionalization (e.g. hydroxylation) of inert C-H bonds. Interestingly, Fe(II)/α-ketoglutarate-dependent oxygenases (KGOs) have been found to perform C-H hydroxylation, as well as other oxyfunctionalization, spontaneously in nature. However, as KGOs are not commercially available, or even extensively studied in this context, their potential is not readily accessible to the chemical industry. This project aims to demonstrate the potential of KGOs in biocatalysis. In order to achieve this, the following challenges will be addressed: i) establishing an enzymatic screening methodology to study the activity and selectivity of recombinant KGOs towards industrially relevant substrates, ii) establishing analytical methods to characterize KGO-catalyzed substrate conversion and product formation. Eventually, the proof-of-principle demonstrated during this project will allow Aminoverse B.V. to develop a commercial biocatalysis kit comprised of KGO enzymes with a diverse activity profile, allowing their application in the sustainable production of either commodity, fine or speciality chemicals. The project consortium is composed of: i) Aminoverse B.V, a start-up company dedicated to facilitate chemical partners towards implementing biocatalysis in their chemical processes, and ii) Zuyd University, which will link Aminoverse B.V. with students and (bio)chemical professionals in creating a novel collaboration which will not only stimulate the development of (bio)chemical students, but also the translation of academic knowledge on KGOs towards a feasible biocatalytic application.
