Vesicles of double hydrophilic pullulan and poly(acrylamide) block copolymers : a combination of synthetic- and bio-derived blocks

The formation of vesicular structures with average diameters from 200 to 300 nm consisting of double hydrophilic diblock copolymers pullulan-b-poly(N,N-dimethylacrylamide) (Pull-b-PDMA) and pullulan-b-poly(N-ethylacrylamide) (Pull-b-PEA) in aqueous solution is described. Bio-derived pullulan was depolymerized and functionalized with alkyne endgroups. Furthermore, azide end functionalized acrylamide blocks PDMA and PEA were synthesized via RAFT polymerization. Individual blocks were conjugated via copper catalyzed azide alkyne cycloaddition (CuAAC) to afford defined double hydrophilic block copolymers. Aqueous solutions of the synthesized block copolymers showed formation of completely hydrophilic vesicles that were observed via various techniques including dynamic light scattering (DLS), static light scattering (SLS), laser scanning confocal microscopy (LSCM), and cryogenic scanning electron microscopy (SEM)

Perencanaan unit pengolahan pangan home industry pudding in cup dengan kapasitas produksi 60 cup/hari

Hidangan penutup (dessert) adalah hidangan yang pada umumnya disajikan pada tahap akhir waktu makan. Salah satu hidangan penutup yang disukai anak-anak hingga orang dewasa ialah pudding. Pudding merupakan makanan pencuci mulut dengan tekstur yang lembut, rasanya manis, dan disajikan dalam bentuk dingin. Pudding susu merupakan salah satu produk olahan susu serta merupakan inovasi produk agar konsumen tidak merasa bosan untuk mengkonsumsi susu. Pudding in cup diproduksi sebanyak 60 cup/hari dengan empat macam varian rasa, yaitu chocolate, milo, oreo, dan strawberry dengan jumlah masing-masing 15 cup. Lokasi produksi terletak di Jalan Kutisari Indah Utara 5/15 Surabaya, Jawa Timur. Usaha pudding in cup dijalankan oleh satu orang pemilik dan tambahan pekerja sebanyak satu orang dengan jam kerja enam jam per hari. Pemasaran pudding in cup dilakukan di area Surabaya melalui media sosial, penyebaran brosur, dan ikut serta dalam berbagai event yang ada. Berdasarkan faktor teknis dan ekonomi, usaha pudding in cup layak didirikan dan dioperasikan karena memiliki laju pengembalian modal sesudah pajak (ROR) sebesar 281,65% yang menunjukkan lebih besar dari nilai MARR 12,87%, waktu pengembalian modal sesudah pajak selama 4,20 bulan., dan titik impas atau Break Even Point (BEP) sebesar 32,80%

Self-assembly of double hydrophilic poly(2-ethyl-2-oxazoline)-b-poly(N-vinylpyrrolidone) block copolymers in aqueous solution

The self-assembly of a novel combination of hydrophilic blocks in water is presented, namely poly(2-ethyl-2-oxazoline)-b-poly(N-vinylpyrrolidone) (PEtOx-b-PVP). The completely water-soluble double hydrophilic block copolymer (DHBC) is formed via copper-catalyzed polymer conjugation, whereas the molecular weight of the PVP is varied in order to study the effect of block ratio on the self-assembly process. Studies via dynamic light scattering, static light scattering as well as microscopy techniques, e.g., cryo scanning electron microscopy or laser scanning confocal microscopy, show the formation of spherical particles in an aqueous solution with sizes between 300 and 400 nm. Particles of the DHBCs are formed without the influence of external stimuli. Moreover, the efficiency of self-assembly formation relies significantly on the molar ratio of the utilized blocks. The nature of the formed structures relies further on the concentration, and indications of particular and vesicular structures are found

Pure hydrophilic block copolymer vesicles with redox- and pH-cleavable crosslinks

The self-assembly of a novel double hydrophilic block copolymer consisting of biocompatible blocks, namely pullulan-b-poly(N-vinylpyrrolidone), is presented. Completely hydrophilic spherical structures with an average apparent radius of 800 nm at increased concentrations in water are observed via dynamic light scattering as well as cryo scanning electron microscopy and confocal laser scanning microscopy techniques. Moreover, the pullulan block is converted to present aldehyde groups acting as anchor point for crosslinker attachments. It is demonstrated, that the oxidized self-assembled particles could be crosslinked via the bifunctional crosslinker cystamine forming dynamic covalent imine linkages with aldehyde groups. The afforded vesicles with an average diameter of 700 nm are stable upon high dilution and could be observed via cryo scanning electron microscopy and transmission electron microscopy. Furthermore, it is possible to cleave the crosslinking bonds with the treatment of acid or the application of a reducing agent. The responsivity is a key feature taking future applications in the biomedical sector into account

Macromolecules

The formation of submicron particles consisting of double hydrophilic diblock copolymers of poly(ethylene oxide) and poly(N-vinylpyrrolidone) (PEO-b-PVP) in aqueous solution is described. Block copolymers were synthesized via reversible deactivation radical polymerization using a PEO-xanthate as macro RAFT/MADIX chain transfer agent. Increasing polymer concentrations in aqueous solutions, the block copolymer is able to self-assemble into spherical structures with apparent hydrodynamic diameters in the range between 200 nm and 2 μm. The self-assembly was further improved by copolymerization with a more hydrophilic monomer, N-vinylimidazole (VIm). Submicron particles from PEO-b-P(VP-co-VIm) were preserved via cross-linking utilizing imidazolium formation with a dihalogenide. Thus, submicron double hydrophilic particles were obtained that are stable in organic solvents and under high dilution. Almost quantitative formation of submicron particles with an average diameter of 200 nm can be afforded by the self-assembly in the polar organic solvent DMF and subsequent crosslinking as well. Furthermore, the obtained particles show a promising ability to incorporate various molecules for delivery and release, here exemplified with simple dyes

Thermoadaptive supramolecular α-cyclodextrin crystallization-based hydrogels via double hydrophilic block copolymer templating

Supramolecular hydrogels play a prominent role in contemporary research of hydrophilic polymers. Especially, hydrogels based on α-cyclodextrin/poly(ethylene glycol) (α-CD/PEG) complexation and crystal formation are studied frequently. Here, the effect of double hydrophilic block copolymers (DHBCs) on α-CD/PEG hydrogel properties is investigated. Therefore, a novel DHBC, namely poly(N-vinylpyrrolidone)-b-poly(oligo ethylene glycol methacrylate) (PVP-b-POEGMA), was synthesized via a combination of reversible deactivation radical polymerization and modular conjugation methods. In the next step, hydrogel formation was studied after α-CD addition. Interestingly, DHBC-based hydrogels showed a significant response to thermal history. Heating of the gels to different temperatures led to different mechanical properties after cooling to ambient temperature, i.e., gels with mechanical properties similar to the initial gels or weak flowing gels were obtained. Thus, the hydrogels showed thermoadaptive behavior, which might be an interesting property for future applications in sensing