Physical Adhesion Research Articles

Soluble Polyimide Coated UHMWPE Fibers with Multiple Property Enhancements: Surface Activity, Tensile Strength, Heat Resistance, Acid Resistance, and Erasability.

Ultrahigh molecular weight polyethylene (UHMWPE) fibers possess excellent mechanical properties, yet their applications are severely limited by surface inertness and low melting points. To enhance surface activity and temperature resistance, soluble polyimide (PI) is applied to the surface of UHMWPE fibers. A mussel-inspired biomimetic polycatechol/polyamine (PA) coating is initially constructed on the UHMWPE fiber surface by oxidative self-polymerization, serving as a secondary reaction platform. Subsequently, multifunctional UHMWPE-PA-PI fibers are prepared by depositing soluble PI on the fiber surface via impregnation. The PA and PI layers are firmly bonded by hydrogen bonding interactions and physical adhesion. The results show that the PI-coated UHMWPE fiber surface exhibits enhanced chemical activity, hydrophilicity, and thermal stability, with an increased thermal decomposition temperature of approximately 30 °C. Compared to pristine UHMWPE, the breaking force of UHMWPE-PA-PI fibers increases by 14.9%, and the interfacial adhesion strength between the fiber and rubber improves by 65.5%. The PI coatings also provide thermal insulation, acid resistance, and erasability functionalities. This modification strategy is highly efficient, simple, and less damaging, offering a novel solution to address UHMWPE fibers' surface inertness and temperature intolerance.

Direct Metal Transfer on Swellable Hydrogel with Dehydration-Induced Physical Adhesion.

Composites of hydrogels and metals are gaining interest because of each material's unique properties. However, the stable adhesion of metals on hydrogels is challenging due to the mechanical mismatch at the soft-hard interface and the liquidity of the water components in hydrogels. We propose a facile physical-adhesion method that involves the dehydration process of hydrogels to transfer metals from a glass substrate. This method is based on the hydrophobic interaction between polymer chains and metals and is stable, even in water. Continuous metal wiring was achieved on a swollen hydrogel, and electrical conduction was effective for a soft electronic device. Therefore, our method could be a versatile method for integrating hydrogels and metals.

Nanocasting synthesis of mesoporous CeO2 particle abrasives from mesoporous SiO2 hard templates for enhanced chemical mechanical polishing performance

Mesoporous abrasive particles exhibit superior chemical mechanical polishing/planarization (CMP) performance, as compared with the corresponding bulk materials. Nevertheless, the lack of control over the shape and particle size or distribution extremely restricts the development of mesoporous abrasives and their potential applications. To overwhelm these drawbacks, pure and ytterbium-doped mesoporous ceria (mCeO2 and mCeYbO2) spheres with well-defined morphology and good uniformity were synthesized via a straightforward nanocasting strategy using high-quality mesoporous silica spheres as hard templates and metal nitrates as precursors. The resulting samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, UV–vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, Zeta potential, and N2 adsorption-desorption measurements. The as-prepared mCeO2 and mCeYbO2 products exhibited enriched surface defects (trivalent Ce, vacancy oxygen, hydroxyls) and polycrystalline porous frameworks with a surface area of up to 160 m2/g and pore size of 4–7 nm. Benefiting from these synergistic attributes, the flexible and defective particle abrasives enabled significant improvements in both surface quality and removal efficiency during oxide-CMP, as compared to commercial CeO2. A possible CMP mechanism was proposed on the basis of the physical contact state, adsorption and adhesion behavior, as well as tribochemical interaction occurred at CeO2–SiO2 interfaces. This work demonstrates highly promising abrasive materials advancement combining architecture and defect engineering towards high-performance oxide-CMP.

Preparation and characteristics of soy protein isolate - Sea buckthorn flavone emulsion and their effects of on quality and heterocyclic amines of roasted mutton granules

A soy protein isolate (SPI) - sea buckthorn flavonoid emulsion was developed to study its effects on roasted lamb quality and heterocyclic amine (HAAs) precursors. The emulsion was stable with uniformly dispersed, well-encapsulated droplets averaging 0.1 to 10 μm. CLSM confirmed its good physical stability, small particle size, and uniform dispersion. FTIR the existence of hydrogen bond, hydrophobic interaction and physical adhesion between SPI and sea-buckthorn flavonoids. The emulsion improved lamb pellet texture by reducing chewiness and hardness, increasing adhesion, and decreasing browning. The emulsion-treated roasted mutton showed a 47.95–53.56 % increase in DPPH scavenging activity and MDA content reduction from 60.78 to 17.80 nmol/mg, indicating strong antioxidant activity and lipid oxidation inhibition. For both precursors and HAAs, there was a significant intensity of inhibition, where creatine decreased by about 44.91–68.34 %, glucose by 84.47 %–97.74 %, and the seven HAAs, Norharman, Harman, IQ, MeIQ, MeIQx, AαC, and PhIP, were inhibited by 79.64 %, respectively, 88.76 %, 65.07 %, 87.27 %, 96.16 %, 89.30 % and 49.44 %, respectively. This study aimed to develop a novel soy protein isolate-sea buckthorn flavonoid emulsion and evaluate its potential to improve roasted lamb quality while inhibiting the formation of harmful HAAs.

Abstract B074: Aberrant pericytes in PDAC: effects on endothelial-pericyte adhesion, vascular integrity, and tumor microenvironment

Abstract Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in men and women in the U.S., with a 5-year survival rate of 13%. Within the PDAC tumor microenvironment (TME), morphologically aberrant leaky vessels are responsible for hypoxia and impaired immune response, which likely reduces the efficacy of cancer therapies. We and others showed that pericyte (PC) coverage significantly correlates with vascular integrity, function, and intratumor hypoxia. Therefore, understanding the contribution of abnormal PC to the TME evolution is a critical step toward PDAC treatment options. Consequently, we hypothesize that correcting such undesirable phenotype via vascular normalization will enhance treatment efficacy. Our study revealed that tumor-associated pericytes across all PDAC tumor tissues exhibited ectopic alpha-smooth muscle actin (αSMA) cytoskeletal protein expression up to 10 times higher than normal pericytes, which was significantly correlated with vascular leakiness and hypoxia. Our previous publication showed that PDAC-derived extracellular vesicles are potent inducers of αSMA expression in pericytes characterized by biomechanical abnormalities. To evaluate the vascular functional defect, we performed a tube formation assay showing abnormal pericytes contribute to abnormal vasculatures in vitro. Our investigation aims to uncover the cause of the abnormal pericyte phenotype that disrupts the physical adhesion between pericytes and endothelial cells (EC), resulting in compromised vasculature. Our findings reveal consistently upregulated monocarboxylate transporters in vascular cells. To enhance EC-pericyte adhesion, we investigated lactate metabolic communication, which is tightly linked due to the proximity of ECs and pericytes. We have shown that in PDAC, MCT1 lactate exporters are upregulated in EC. Conversely, MCT12 lactate importers are highly expressed in pericytes. The high amount of lactate produced by ECs decreases the pH in the basement membrane. So, we knocked down MCT1 transporters in ECs to increase basement pH, leading to improved PC-EC attachment and pericyte homeostasis. Finally, we performed single-cell RNA sequencing to determine the pathological signature of tumor pericytes and identify potential target molecules for vascular normalization. In conclusion, our study indicates that tumor-associated pericytes undergo phenotype switching and disturbed metabolic communication under the influence of pancreatic cancer cells. These aberrant pericytes might contribute to non-optimal vascular integrity and function. Single-cell RNA sequencing helped understand the molecular signature of the PDAC pericyte, providing a powerful tool to develop novel targeting strategies for vascular normalization. Future work includes exploring the vascular normalization approach by suppressing pericyte phenotype switching to enhance vascular function and chemo- and immunotherapeutic efficacy. Citation Format: Vikneshwari Natarajan, Sangdeuk Ha, Jiha Kim. Aberrant pericytes in PDAC: effects on endothelial-pericyte adhesion, vascular integrity, and tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B074.

Water-resistant adhesive tackified by dynamic adhesion factor of nucleotide

Underwater adhesives have gained much attention across diverse fields including tissue adhesives, wearable electronics, and underwater electronics. However, it remains challenging to design a tough and stable underwater adhesion interface only relying on physical adhesion mechanisms, because the adhesion factors of the physical adhesives are limited and bound by molecular networks. Inspired by the toughening theory of “sacrificial bonds”, we present a strategy of dynamic adhesion factor to fabricate a tough and stable underwater adhesion interface. The adhesives tackified by nucleotide of dynamic adhesion factor are successfully developed and demonstrate excellent adhesion behavior in aquatic environments. The adhesion factor of nucleotide featuring reversible dynamic structural characteristics not only facilitates easier interaction with the substrate but also effectively dissipates failure stress and mitigates stress concentration when exposed to destructive stress. Moreover, the adhesives exhibit excellent recyclability, on-demand detachability, and long-term stability. Importantly, this strategy demonstrated a universality for variable monomers to construct tough underwater adhesion. It is anticipated that the dynamic adhesion factor strategy will inspire a new paradigm in the advancement of next-generation water-resistant adhesives.

Synergistic effects of the physical modification and chemical passivation enabling efficient perovskite solar cells

Inverted perovskite solar cells (IPSCs) with poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) as hole transport materials exhibit superior stability and low-temperature processibility. However, the hydrophobicity of PTAA renders it difficult to prepare high-quality perovskite films due to the low wettability of perovskite precursor solutions, resulting in poor crystallization of perovskites and undesirable interface properties of PTAA/perovskites. Herein, a porous layer of Al2O3 nanoparticles functionalized using 2-thenoylacetonitrile (2-T-OACN) molecules is incorporated into the PTAA/perovskite interface. The physical adhesion of Al2O3 nanoparticles on the PTAA layer could enhance the surface wettability for perovskite precursor solutions, resulting in uniform perovskite films being realized on the PTAA layer. Meanwhile, 2-T-OACN adsorbed on the Al2O3 nanoparticles could form C=O··· Pb2+ and C≡N ···Pb2+ coordination interactions with the bottom surface of perovskites, thus passivating the defects at the PTAA/perovskite interface. Moreover, the electron-rich thiophene groups in 2-T-OACN molecules further promote interfacial charge carrier transport and thus significantly lower the interfacial recombination. Consequently, the IPSCs show a high efficiency of 23.3 %, which is largely improved compared with that of 19.4 % efficiency for control IPSCs. The synergistic strategy of the physical modification and chemical passivation provides a feasible approach for modulating the crystallization of perovskites and buried interface properties for IPSCs.

Dual-ROS-scavenging and dual-lingering nanozyme-based eye drops alleviate dry eye disease

Efficiently removing excess reactive oxygen species (ROS) generated by various factors on the ocular surface is a promising strategy for preventing the development of dry eye disease (DED). The currently available eye drops for DED treatment are palliative, short-lived and frequently administered due to the short precorneal residence time. Here, we developed nanozyme-based eye drops for DED by exploiting borate-mediated dynamic covalent complexation between n-FeZIF-8 nanozymes (n-Z(Fe)) and poly(vinyl alcohol) (PVA) to overcome these problems. The resultant formulation (PBnZ), which has dual-ROS scavenging abilities and prolonged corneal retention can effectively reduce oxidative stress, thereby providing an excellent preventive effect to alleviate DED. In vitro and in vivo experiments revealed that PBnZ could eliminate excess ROS through both its multienzyme-like activity and the ROS-scavenging activity of borate bonds. The positively charged nanozyme-based eye drops displayed a longer precorneal residence time due to physical adhesion and the dynamic borate bonds between phenyboronic acid and PVA or o-diol with mucin. The in vivo results showed that eye drops could effectively alleviate DED. These dual-function PBnZ nanozyme-based eye drops can provide insights into the development of novel treatment strategies for DED and other ROS-mediated inflammatory diseases and a rationale for the application of nanomaterials in clinical settings.Graphical

Biocompatible Composite Filaments Printable by Fused Deposition Modelling Technique: Selection of Tuning Parameters by Influence of Biogenic Hydroxyapatite and Graphene Nanoplatelets Ratios.

The proposed strategy for the extrusion of printable composite filaments follows the favourable association of biogenic hydroxyapatite (HA) and graphene nanoplatelets (GNP) as reinforcement materials for a poly(lactic acid) (PLA) matrix. HA particles were chosen in the <40 μm range, while GNP were selected in the micrometric range. During the melt-mixing incorporation into the PLA matrix, both reinforcement ratios were simultaneously modulated for the first time at different increments. Cylindrical composite pellets/test samples were obtained only for the mechanical and wettability behaviour evaluation. The Fourier-transformed infrared spectroscopy depicted two levels of overlapping structures due to the solid molecular bond between all materials. Scanning electron microscopy and surface wettability and mechanical evaluations vouched for the (1) uniform/homogenous dispersion/embedding of HA particles up to the highest HA/GNP ratio, (2) physical adhesion at the HA-PLA interface due to the HA particles' porosity, (3) HA-GNP bonding, and (4) PLA-GNP synergy based on GNP complete exfoliation and dispersion into the matrix.

Hybrid Epoxy Composites Based on Basalt Fabric: A Case Study of Low‐Temperature Plasma Treatment and Reduced Graphene Oxide Flakes Addition

The purpose of this study is to present a novel method for producing mechanically strong epoxy composite laminates of different compositions, reinforced with basalt fabric and reduced graphene oxide flakes. The laminates are prepared with basalt fabric, which is subjected to low‐temperature plasma treatment. This approach is aimed to enhance the adhesion of fabric to resin filled with reduced graphene oxide flakes. Physical properties, adhesion, and mechanical properties of the obtained materials are determined. Based on the experiments, it is found that the tensile strength is improved by 6–21% after using reduced graphene oxide filler, 9–23% after plasma treatment, and up to 27% using the combination of plasma and reduced graphene. It is found that the highest improvement of tensile strength is obtained for epoxy composite with 0.5 wt% graphene‐based filler and 3 min basalt fiber plasma treatment with 25 W plasma power.

Preparation and properties of high abrasion resistant superhydrophobic coating on the PCB

Abrasion resistance has become the bottleneck restricting the application of superhydrophobic surface. It is extremely necessary to design superhydrophobic surface with high abrasion resistance in practical application environment. However, the coexistence of superhydrophobic property and abrasion resistance is a difficult challenge to balance. In this study, a superhydrophobic coating with high abrasion resistance was obtained in combination with three gradients of roughness/wettability, physical adhesion and chemical coupling on the printed circuit board (PCB) surface. The realization of high abrasion resistance of the coating mainly depended on controlling the curing time of the adhesive layer and the way of air injection, so that the micro-nano structure could achieve the effect of semi-embedded. The PCB surface still maintained superhydrophobicity with the water contact angle higher than 150° after a series of tests such as 800 cycles of tape peeling, 400 cycles of knife scraping, 2600 cm of sandpaper abrasion, 425 g of falling sand impacting, and 60 min of water impacting, which fully proved the high abrasion resistance of the coating and the strong adhesion between the coating and the substrate. The preparation process is high efficiency and suitable for large area application, which will provide an extremely valuable idea for improving the waterproof of PCB and promote the true applications of superhydrophobic coating in many fields.

Novel solar-induced wastewater purification materials originated from ore tailing solid waste

Ore tailings (OT) are solid waste produced as a by-product of the mining industry, posing serious environmental challenges. Ensuring the low-carbon and environmentally friendly development of mineral raw materials, enhancing the reclamation, reuse and recycling rate of raw materials in the full lifecycle, presents a significant challenge. To achieve high-value utilization of OT and solve the problem of clean water supply, a novel solar evaporation wastewater purification material was developed using modified ore tailing/acrylate composite photothermal coating. The photothermal functional modified ore tailings (OT@PDA@CB) were fabricated by grafting carbon black (CB) and polydopamine (PDA) onto the OT surface through the physical adhesion of active chemical groups, synergistically enhancing broadband light absorption ability of OT@PDA@CB/acrylate coating. UV–Vis-NIR spectra showed increased absorption in visible and near-infrared (NIR) light. Surface temperature of OT@PDA@CB/acrylate coating under 1200 W/m−2 illumination increased to 65.6 °C compared with 52.6 °C of OT/acrylate coating due to increased light absorption, resulting in an evaporation rate of 0.89 kg·m−2·h−1 within 1 h. The solar evaporation efficiency for OT@PDA@CB evaporator was 48.3%, which was 192.7% higher than that in blank acrylate sample. The obtained OT@PDA@CB/acrylate composite photothermal coating demonstrated versatile abilities for desalination, heavy-metal purification and organic contaminant removal. This work offers a straightforward approach for high-value utilization of inexpensive mineral solid wastes and green solar-induced wastewater purification technique.

Enhancing Electrical and Physical Contacts of Copper‐Electroplated Silicon Heterojunction Solar Cells through Chemical Pretreated Seed Layers

Copper electroplating offering the potential to replace low‐temperature sintered silver pastes holds significant promise as a metallization process for silicon heterojunction (SHJ) solar cells (SCs). To unlock the full potential of copper electroplating, it is crucial to enhance the contact properties between the electroplated grids and the indium tin oxide (ITO) films, addressing both contact resistivity and physical adhesion. Herein, a zinc‐assisted Fe2+ system to modify the ITO film is used, leading to the formation of an In/Sn/SnO mixed‐metal transition layer. This transition layer serves as a seed layer for metal electroplating, reducing contact resistivity and enhancing the mechanical connection between the electroplated metals and the ITO films. Following the ITO pretreatment process, the contact resistivity is significantly reduced from 1.4 to 0.2 mΩ cm2, and the peel force value of the pretreated sample reaches 14.2 N mm−1, which is 75.3% higher than that of the untreated sample. The proof‐of‐concept SHJ SC with copper electroplating after ITO pretreatment achieves a remarkable power conversion efficiency of 22.6%. These results clearly demonstrate that ITO pretreatment using the zinc‐assisted Fe2+ system is an effective approach for enhancing contact properties and improving the performance of copper‐electroplated SHJ SCs, showcasing significant potential for industry applications.

Enhancing interfacial adhesion and electrical conductivity of steel/polymer composites via molecular adhesion for sustainable structural materials

Steel/Polymer Composites (SPCs) represent a promising class of materials that combine the strengths of steel and polymers, making them ideal candidates for various structural applications. Notably, they offer heat shielding properties, energy absorption, reduced noise, vibration, and harshness, high rigidity, as well as weight reduction benefits. Achieving robust interfacial adhesion between steel and polymer, while maintaining electrical conductivity for welding, presents a significant challenge in SPC development. Conventional SPCs relying on physical adhesion through polymer coating are susceptible to environmental factors, compromising durability. To address this, novel adhesion concepts are explored, leveraging molecular-level interactions. In this study, we investigate the adhesion between electro-galvanized iron steel treated with a phosphate conversion coating and four polymers: polyethylene (PE), acrylonitrile-butadiene-styrene (ABS), Nylon 6, and Polyketone. The primary amines are anchored on the steel surface using 3-aminopropyltriethoxysilane (APTES), while maleic anhydride (MA) is introduced onto the polymer chains. The adhesion strength of the SPCs dramatically increased from 0 to 11.5 MPa for PE, from 1.5 to 11.1 MPa for ABS, from 12.7 to 14.1 MPa for Nylon 6 and from 7.1 to 14.2 for Polyketone. In particular, the adhesion strength of Nylon 6 was maintained at 89.0% for 7 d aging despite moisture absorption being fatal to interfacial adhesion. The findings suggest two presumable interactions at the steel/polymer interface, including molecular adhesion. In order to enable spot welding of these SPCs, mechano-chemistry was employed to embed carbon-based graphitic materials within the plastic matrix, enhancing electrical conductivity. The selection of Polyketone as a core material facilitates the adsorption of conductive fillers, such as Carbon Nanotubes (CNT) and Graphite Platelets (GPs). Graphite Nanoplatelets-Polyketone, with smaller lateral dimensions (50 ∼ 100 nm), exhibits the highest electrical conductivity of 207.5 S/cm. Scanning Electron Microscopy (SEM) confirms effective filler adsorption without pre-treatment. This comprehensive study enhances our understanding of SPC development, shedding light on innovative approaches to achieve robust adhesion, electrical conductivity, and suitability for spot welding applications.

Investigations of the influence of organic aggregate on physical mechanical and adhesion properties of sulfur-containing arbolite

The main issue of this study is to investigate the effect of the porous structure of organic aggregate on cement stone and on the nature of the contact zone. As it is known, porous aggregate draws away some of the moisture from the adjacent cement stone layers, which promotes their compaction. In turn, the contact layers of the sulfur-containing binder also undergo changes. Also in the work, sulfur and its derivatives are used as an additive for chemical treatment. It is known that sulfur itself is a strong reducing agent, so it can affect the morphology and chemical composition of the surface of the organic aggregate of sulfur-containing arbolites. It was found that the highest index of efficiency coefficient equal to 1.02 and 1.01 have samples of sulfur-containing arbolite based on shredded cane and cotton stalks. The study of the structure of contact zones of sulfur-containing binder with shredded mercerized cane on samples from the binder dough with inclusion of shredded cane fiber showed that it has a dense and strong binder shell with a width of 35-60 μm. The results confirm that mercerization of cellulosic organic aggregates of sulfur-containing arbolites increases its adhesion ability. The obtained results of the study can be used for the manufacture of wall materials for low-rise construction.

Advances in Regulating Cellular Behavior Using Micropatterns.

Micropatterns, characterized as distinct physical microstructures or chemical adhesion matrices on substance surfaces, have emerged as a powerful tool for manipulating cellular activity. By creating specific extracellular matrix microenvironments, micropatterns can influence various cell behaviors, including orientation, proliferation, migration, and differentiation. This review provides a comprehensive overview of the latest advancements in the use of micropatterns for cell behavior regulation. It discusses the influence of micropattern morphology and coating on cell behavior and the underlying mechanisms. It also highlights future research directions in this field, aiming to inspire new investigations in materials medicine, regenerative medicine, and tissue engineering. The review underscores the potential of micropatterns as a novel approach for controlling cell behavior, which could pave the way for breakthroughs in various biomedical applications.

Evaluating ammonia sensors based on two-dimensional pure and silicon-decorated biphenylene using DFT calculations

Within this piece of research, the performance of two-dimensional pure and silicon-decorated monolayers of biphenylene (PBPML and SBPML) in detecting ammonia (NH3) was investigated though DFT calculations. In spite of the fact that PBPML adsorbed NH3 better than other reported 2D materials, NH3 had a physical adhesion on the surface of PBPML and the adhesion energy was −0.037 eV. After decorating the Si atom, the NH3 adhesion capacity of PBPML changed significantly and there was a dramatic change in its electronic attributes. The SBPML can be considered as an encouraging sensor for NH3 with a structural solidity at ambient temperatures, the recovery time of 0.84 s at 300 K, charge transport of 0.56 e and significant adhesion energy of −0.72 eV. The results demonstrated that the SBPML was suitable for sensing NH3 and it was suitable for practical applications. This work can provide insights into the designing and development of biomolecule sensors with high efficiency.

Geometry effect of different PTFE fillers on self-lubricating PF composites: Mechanical and tribological properties

In order to further improve the performance of polytetrafluoroethylene (PTFE) as lubricant additives, PTFE fiber bundles (PTFE-F) were prepared by wet spinning to enhance phenolic resin (PF), and PTFE powders (PTFE-P) were used as a contrast phase. PF-based composites were prepared by hot pressing sintering, and their tribological properties were tested by ball-on-disc friction tests. The results showed that the shore hardness and compressive strength of PF-15 wt% PTFE-F were severally 5.8 % and 58.6 % higher than that of PF-15 wt% PTFE-P. The COF of PF-15 wt% PTFE-F and PF-15 wt% PTFE-P were 0.102 and 0.088, while the wear rates were 2.53 × 10−7mm3/Nm and 1.59 × 10−4 mm3/Nm respectively, with a difference of 628 times. It has been demonstrated that the transfer film formed on the friction pair ball is multi-layer structure, which formed by the physical adhesion of PTFE and the tribochemical reaction between the PTFE and the steel ball. Therefore, the geometry effect idea can be used to fabricate a new kind of self-lubricating materials applied widely in the fields of navigation, aviation, and aerospace.

Formulation and Evaluation of Serum Gel from Sengkubak Leaf Extract (Pycnarrhena Cauliflora Diels)

Background: Serum has a high concentration but a low viscosity. a facial serum that has a fairly good ability to absorb into the skin, releases the active substance of the serum well and is easy to apply to the face. Sengkubak (Pycnarrhena cauliflora Diels) is a type of plant in the Menispermaceae family which can be found in West Kalimantan. Sengkubak also has good potential to be developed as a source of antioxidant compounds Objectives: Knowing the optimal formulation of sengkubak leaf extract serum gel (Pycnarrhena Cauliflora Diels) and knowing the evaluation of the physical properties of Sengkubak leaf extract serum gel (Pycnarrhena Cauliflora Diels) Method: The study used a quasi-experimental design method with varying concentrations of 1 gram, 1.5 grams and 2 grams of natrosol. Serum gel was evaluated for physical organoleptic, homogeneity, spreadability, dry time, adhesion, pH, and viscosity. Results: The results of the observations on the viscous liquid organoleptic test and on the homogeneity test of homogeneous preparations. the most optimal spreadability test results were formulation 1, the most optimal drying time was formulation 1. the most optimal adhesion test results were formulation 1, the most optimal ph test results were formula 1, and the most optimal viscosity test were formulation 2. Conclusion: The most optimal serum gel of sengkubak leaf extract (Pycnarrhena Cauliflora Diels) is formulation 1, with a concentration of 1 gram.

Investigation of novel natural polymer composition with acacia for the production of disposable plastic like material

In a different perspective to natural polymers’ methodologies and techniques, this research explores the possibility of the production of natural plastic-like material by different methodology, relying on and benefiting from natural bonding between the components, and with minor energy consumed to achieve the highest possible material strength. The methodology is similar to the followed methodology in the production of polycarbonate plastics, depends on molecular interactions rather than physical adhesion forces, Similar to many of the petroleum-based plastics types fabrication, the blending technique followed the default polycarbonate plastics technique; which is mixing binder, solvent and thickening agent by equal ratios, while additives by determined ratios are added to acquire the blend specific physical and mechanical properties. however, the used components are 100 % natural components, to obey the global trends for cleaner and greener environment. The composites have been prepared from Acacia as a binder, starch as thickening agent filler, and water as the matrix solvent, cellulosic fibers and glycerine are added by limited ratios as additives, then the composites were subjected to different characterization techniques to measure some mechanical properties such as tensile strength and degradability. The results showed good strength values. Natural sustainable degradable composites have been obtained and 5.217 MPa tensile strength has been achieved without any mechanical, chemical or physical treatments, which is much higher than the same TPS if cured in the same conditions without any treatments.