Effects of surfactant adjuvants on plant leaf cuticle barrier properties

التفاصيل البيبلوغرافية
العنوان:	Effects of surfactant adjuvants on plant leaf cuticle barrier properties
بيانات النشر:	Malmö högskola, Institutionen för biomedicinsk vetenskap (BMV) Malmö University, Faculty of Health and Society 2014
تفاصيل مُضافة:	Fagerström, Anton
نوع الوثيقة:	Electronic Resource
مستخلص:	I avhandlingen undersöks växelverkan mellan det yttersta lagret på växters blad (cutikeln), aktiva substanser, och ämnen som tillsätts för att öka bekämpningsmedlens effekt, i detta fall vissa former av tensider. Barriären som hindrar upptag av främmande ämnen i växten sitter i cutikeln. Det är väl känt att tensider förstärker effekten av aktiva substanser. Kunskapen är dock liten om de mekanismer som underlättar upptaget i växtblad. Det övergripande målet i avhandlingen är att öka kunskapen om hur dessa mekanismer verkar. Att klargöra vilka effekter tensider har på cutikeln och hur dessa möjliggör ett ökat upptag av aktiva substanser. Ytterligare ett mål är att bidra till en mer ekologiskt hållbar användning och förnuftig applicering av bekämpningsmedel inom jordbrukssektorn. Det senare av dessa två mål kan uppnås genom att använda den mest effektiva tensiden för respektive bekämpningsmedel, samt det mest effektiva bekämpningsmedlet för respektive växtsort för att på så vis minimera mängden bekämpningsmedel. Men optimering kräver givetvis förståelse. Det övergripande målet har uppnåtts genom kartläggning av vad som sker i växelverkan mellan tensid, vatten och växtblad. Beståndsdelarna som upprätthåller bladets barriäregenskaper beskrivs, samt hur deras smältbeteende och strukturella egenskaper förändras då vatten tillförs och då tensider är närvarande. En ny modell av vaxbarriären i cutikeln etableras och kartläggs. Modellen används till att undersöka de mjukgörande effekterna tensider och vatten har på cutikeln. Hur tensider ordnar sig i en vattenlösning och hur ordningen förändras när vatten avdunstar beskrivs i avhandlingen. Vidare kartläggs hur tensider absorberas i cutikeln och vilka strukturer som påverkas där. Drivkraften för upptag av bekämpningsmedel i växtblad förklaras, hur tensider påverkar drivkraften och vilka egenskaper hos en blandning som påverkar upptaget utrönas. Hur tensider påverkar parametrar i barriären beskrivs också. Dessa parametrar behand The focus of this project has been the mechanisms of action of surfactants as agricultural adjuvants and the physico-chemical interactions between adjuvant, carrier formulation, and leaf surface. To increase the understanding of this complex system, model systems have been evaluated in parallel to in vitro studies of plant leaf cuticle. Investigations on how thermodynamic, structural and rheological properties of leaf surface constituents are affected by surfactant absorption and hydration have been central. The main techniques employed in the project are: Environmental Scanning Electron Microscopy, Differential Scanning Calorimetry, Optical Phase Contrast Microscopy with Temperature Resolution, Quartz Crystal Microbalance with Dissipation, Small- and Wide-angle X-ray Diffraction, and Franz type diffusion cells. The effects that surfactants exert on the structure of native intact plant leaf cuticle were investigated by Small- and Wide-Angle X-ray diffraction (SWAXD). The wax has a broad melting interval between 40 and 80 C which comprises a crystalline transition from orthorhombic to hexagonal sub-cell. This transition is facilitated by addition of surfactants. Both intact cuticle and extracted wax also possess lamellar long range order. Clivia is an appropriate model plant since it is related to, and has similar leaf characteristics as, some of the most important crop plants, wheat and barley. It is easy to cultivate indoors, and the leaves are wide enough to be evaluated in vitro through diffusion cell experiments. The barrier is very tough; if it works on Clivia it most probably will work in the field as well. The model of plant leaf intracuticular wax can be used to estimate formulations effects on the cuticle structure. A model was based on a leaf wax extract and comprised 1-docosanol (C22H45OH) and dotriacontane (C32H66). The thermotropic phase behaviour of the model was investigated, and the structure of individual phases in the model wax - water system was d
مصطلحات الفهرس:	Adjuvant, Surfacant, Cuticle, Tebuconazole, Diffusion, Clivia miniata Regel leaf, Model wax, Phase diagram, Hydration, Eutectic melting, Crystalline domains, Softening, Wax film, Quartz Crystal Microbalance with dissipation (QCM-D), Differential Scanning Calorimetry (DSC), Small- and Wide-angle X-ray Diffraction (SWAXD), Natural Sciences, Naturvetenskap, Doctoral thesis, comprehensive summary, info:eu-repo/semantics/doctoralThesis, text
URL:	http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-7345 Malmö University Health and Society Dissertations, 1653-5383 ; 3
الإتاحة:	Open access content. Open access content info:eu-repo/semantics/openAccess
ملاحظة:	application/pdf English
أرقام أخرى:	UPE oai:DiVA.org:mau-7345 urn:isbn:978-91-7104-576-8 urn:isbn:978-91-7104-575-1 Local 17029 1234789958
المصدر المساهم:	UPPSALA UNIV LIBR From OAIster®, provided by the OCLC Cooperative.
رقم الأكسشن:	edsoai.on1234789958
قاعدة البيانات:	OAIster

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